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Introduction The empty pelvis syndrome is a significant source of morbidity following pelvic exenteration surgery. It remains poorly defined with research in this field being heterogeneous and of low quality. Furthermore, there has been minimal engagement with patient representatives following pelvic exenteration with respect to the empty pelvic syndrome. ‘PelvEx—Beating the empty pelvis syndrome’ aims to engage both patient representatives and healthcare professionals to achieve an international consensus on a core outcome set, pathophysiology and mitigation of the empty pelvis syndrome.Methods and analysis A modified-Delphi approach will be followed with a three-stage study design. First, statements will be longlisted using a recent systematic review, healthcare professional event, patient and public engagement, and Delphi piloting. Second, statements will be shortlisted using up to three rounds of online modified Delphi. Third, statements will be confirmed and instruments for measurable statements selected using a virtual patient-representative consensus meeting, and finally a face-to-face healthcare professional consensus meeting.Ethics and dissemination The University of Southampton Faculty of Medicine ethics committee has approved this protocol, which is registered as a study with the Core Outcome Measures in Effectiveness Trials Initiative. Publication of this study will increase the potential for comparative research to further understanding and prevent the empty pelvis syndrome.Trial registration number NCT05683795.

Purpose: Patterns of failure and salvage therapy options for patients with anal squamous cell carcinoma (ASCC) who recur after definitive-intent intensity-modulated radiation therapy (IMRT) with concurrent chemotherapy are not well described., Methods and Materials: We identified consecutive patients with ASCC treated with definitive-intent IMRT between July 2005 and December 2019. Relevant patient and tumor parameters, disease outcomes (locoregional failure [LRF], distant failure, progression-free survival, colostomy-free survival, and overall survival [OS]), patterns of failure, and salvage therapies were collected. Failures were analyzed using competing risk methods, whereas survival endpoints were estimated using the Kaplan-Meier method. Univariate and multivariate analyses were performed. Landmark analyses were conducted by considering whether patients had LRF within 12 months of completing IMRT., Results: A total of 375 patients were identified with a median follow-up of 6 years. Stage breakdown was 15%, 23%, and 62% for the American Joint Committee on Cancer stages 0 to I, II, and III, respectively. Six-year rates of LRF, distant failure, progression-free survival, colostomy-free survival, and OS were 12%, 13%, 73%, 76%, and 80%, respectively. Disease recurred in 74 patients. Among the 45 patients with LRF, 39 (87%) failed within the anorectum, with 25 anal canal, 6 anal margin, and 8 rectal recurrences. Only 4 (9%) patients had isolated nodal failure. Patients experiencing LRF had worse 6-year OS than patients without LRF (44% vs 86%, P < .0001). Approximately 30% of patients who underwent salvage therapy were alive to 10 years after recurrence, compared with none of the patients who were managed with chemotherapy alone or the best supportive care., Conclusions: This large ASCC cohort managed with definitive-intent IMRT demonstrated excellent rates of locoregional control and survival. Isolated regional nodal failures were uncommon, whereas the majority of LRFs occurred within the anorectum, despite dose escalation by tumor stage. We observed poor outcomes for patients experiencing locoregional disease recurrence, even after aggressive salvage treatment., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Potential differences in organ preservation between total neoadjuvant therapy (TNT) regimens integrating long-course chemoradiotherapy (LCCRT) and short-course radiotherapy (SCRT) in rectal cancer remain undefined., Patients and Methods: This natural experiment arose from a policy change in response to the COVID-19 pandemic during which our institution switched from uniformly treating patients with LCCRT to mandating that all patients be treated with SCRT. Our study includes 323 locally advanced rectal adenocarcinoma patients treated with LCCRT-based or SCRT-based TNT from January 2018 to January 2021. Patients who achieved clinical complete response were offered organ preservation with watch-and-wait (WW) management. The primary outcome was 2-year organ preservation. Additional outcomes included local regrowth, distant recurrence, disease-free survival (DFS), and overall survival (OS)., Results: Patient and tumor characteristics were similar between LCCRT (n = 247) and SCRT (n = 76) cohorts. Median follow-up was 31 months. Similar clinical complete response rates were observed following LCCRT and SCRT (44.5% versus 43.4%). Two-year organ preservation was 40% [95% confidence interval (CI) 34% to 46%] and 31% (95% CI 22% to 44%) among all patients treated with LCCRT and SCRT, respectively. In patients managed with WW, LCCRT resulted in higher 2-year organ preservation (89% LCCRT, 95% CI 83% to 95% versus 70% SCRT, 95% CI 55% to 90%; P = 0.005) and lower 2-year local regrowth (19% LCCRT, 95% CI 11% to 26% versus 36% SCRT, 95% CI 16% to 52%; P = 0.072) compared with SCRT. The 2-year distant recurrence (10% versus 6%), DFS (90% versus 90%), and OS (99% versus 100%) were similar between WW patients treated with LCCRT and SCRT, respectively., Conclusions: While WW eligibility was similar between cohorts, WW patients treated with LCCRT had higher 2-year organ preservation and lower local regrowth than those treated with SCRT, yet similar DFS and OS. These data support induction LCCRT followed by consolidation chemotherapy as the preferred TNT regimen for patients with locally advanced rectal cancer pursuing organ preservation., (Copyright © 2024 European Society for Medical Oncology. Published by Elsevier Ltd. All rights reserved.)

Background: Neoadjuvant therapy leads to a clinical complete response in a considerable proportion of patients with locally advanced rectal cancer, allowing for possible nonoperative management. The presence of mucin on magnetic resonance imaging (MRI) after neoadjuvant therapy leads to uncertainty about residual disease and appropriateness of a watch-and-wait strategy in patients with no evidence of disease on proctoscopy (endoscopic clinical complete response)., Methods: MRI reports for locally advanced rectal cancer patients seen between July 2016 and January 2020 at Memorial Sloan Kettering Cancer Center were queried for presence of mucin in the tumor bed on MRI following neoadjuvant therapy. Clinicodemographic, pathologic, and outcome data were compiled and analyzed., Results: Of 71 patients with mucin on posttreatment MRI, 20 had a clinical complete response, and 51 had abnormalities on endoscopy and/or physical exam. One patient with a clinical complete response opted out of watch-and-wait; thus, 19 (27%) patients entered watch-and-wait, and 52 (73%) patients were planned for surgery (non-watch-and-wait). Of the 19 watch-and-wait patients, 15 (79%) have had no local regrowth with median follow-up of 50 months (range = 29-76 months), while 4 (21%) experienced regrowth between 9 and 29 months after neoadjuvant therapy. Of the 52 patients who were planned to have surgery (non-watch-and-wait), 49 underwent resection while 3 developed metastatic disease that precluded curative-intent surgery. Of the 49 patients who underwent surgery, 5 (10%) had a pathologic complete response (including the patient with an endoscopic clinical complete response)., Conclusions: The presence of mucin after neoadjuvant therapy for locally advanced rectal cancer does not preclude watch-and-wait management in otherwise appropriate candidates who achieve an endoscopic clinical complete response., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

As cancers progress, they become increasingly aggressive-metastatic tumours are less responsive to first-line therapies than primary tumours, they acquire resistance to successive therapies and eventually cause death 1,2 . Mutations are largely conserved between primary and metastatic tumours from the same patients, suggesting that non-genetic phenotypic plasticity has a major role in cancer progression and therapy resistance 3-5 . However, we lack an understanding of metastatic cell states and the mechanisms by which they transition. Here, in a cohort of biospecimen trios from same-patient normal colon, primary and metastatic colorectal cancer, we show that, although primary tumours largely adopt LGR5 + intestinal stem-like states, metastases display progressive plasticity. Cancer cells lose intestinal cell identities and reprogram into a highly conserved fetal progenitor state before undergoing non-canonical differentiation into divergent squamous and neuroendocrine-like states, a process that is exacerbated in metastasis and by chemotherapy and is associated with poor patient survival. Using matched patient-derived organoids, we demonstrate that metastatic cells exhibit greater cell-autonomous multilineage differentiation potential in response to microenvironment cues compared with their intestinal lineage-restricted primary tumour counterparts. We identify PROX1 as a repressor of non-intestinal lineage in the fetal progenitor state, and show that downregulation of PROX1 licenses non-canonical reprogramming., Competing Interests: Competing interests: K.G. is listed as an inventor on US patent 11,464,874, and US provisional patent applications 63/478,809 and 63/478,829 on targeting L1CAM to treat cancer, submitted by MSKCC. D.P. is on the scientific advisory board of Insitro. J.S. is a consultant for Paige AI. R.Y. has served on the advisory board for Pfizer, Mirati Therapeutics, Revolution Medicine, Loxo@Lilly and Amgen, received a speaker’s honorarium from Zai Lab, and has received research support from Pfizer, Boehringer Ingelheim, Mirati Therapeutics, Daiichi Sankyo, FogPharma and Boundless Bio. J.G.-A. owns stock in Intuitive Surgical. R.C. is a consultant for Sanavia Oncology, S2 Genomics and LevitasBio. The other authors declare no competing interests., (© 2024. The Author(s).)

Purpose: Outcome for patients with nonmetastatic, microsatellite instability (MSI) colon cancer is favorable: however, high-risk cohorts exist. This study was aimed at developing and validating a nomogram model to predict freedom from recurrence (FFR) for patients with resected MSI colon cancer., Patients and Methods: Data from patients who underwent curative resection of stage I, II, or III MSI colon cancer in 2014-2021 (model training cohort, 384 patients, 33 events; median follow-up, 38.8 months) were retrospectively collected from institutional databases. Variables associated with recurrence in multivariable analysis were selected for inclusion in the clinical calculator. The calculator's predictive accuracy was measured with the concordance index and validated using data from patients who underwent treatment for MSI colon cancer in 2007-2013 (validation cohort, 164 patients, eight events; median follow-up, 84.8 months)., Results: T category and number of positive lymph nodes were significantly associated with recurrence in multivariable analysis and were selected for inclusion in the clinical calculator. The calculator's concordance index for FFR in the model training cohort was 0.812 (95% CI, 0.742 to 0.873), compared with 0.759 (95% CI, 0.683 to 0.840) for the staging schema of the eighth edition of the American Joint Committee on Cancer Staging Manual. The concordance index for the validation cohort was 0.744 (95% CI, 0.666 to 0.822), confirming robust predictive accuracy., Conclusion: Although in general patients with nonmetastatic MSI colon cancer had favorable outcome, patients with advanced T category and multiple metastatic lymph nodes had higher risk of recurrence. The clinical calculator identified patients with MSI colon cancer at high risk for recurrence, and this could inform surveillance strategies. In addition, the model could be used in trial design to identify patients suitable for novel adjuvant therapy.

(1) Background: Adenosquamous carcinoma (ASC) is a rare subtype of colon cancer. Its rarity makes characterization challenging, although colonic ASC is believed to present at more advanced stages and have worse outcomes versus adenocarcinoma. This study aims to characterize the clinicopathological characteristics and clinical outcomes of colonic ASC. (2) Methods: This is a single-center, retrospective review of patients diagnosed with colonic ASC from 2000 to 2020. Data extracted included patient demographics, staging at diagnosis, tumor clinicopathologic and genetic characteristics, and clinical outcomes. (3) Results: Among 61,126 patients with colorectal cancer, 13 (0.02%) had colonic ASC, with a mean age at diagnosis of 48.7 years. The cecum/ascending colon was the most common primary site (6/13, 46.2%), and all except one patient was diagnosed with Stage III or IV disease. Among the eight patients with mismatch repair genetics available, only one was mismatch repair deficient. Eleven patients (84.6%) underwent surgery, and 11 likewise received some form of chemotherapy. Recurrence occurred in 7 of 13 patients (53.8%), and the overall five-year survival rate was 38.5%. The median survival rate was 39.4 months overall (30.5 months for Stage III, 23.7 months for Stage IV). (4) Conclusions: Overall, colonic ASC is rare, and this cohort of colonic ASC patients demonstrated advanced stage at diagnosis, frequent recurrence, and poor overall survival. Additional research remains to compare these characteristics with those of comparably staged adenocarcinoma and to develop specific management recommendations.

Objective: To establish globally applicable benchmark outcomes for pelvic exenteration (PE) in patients with locally advanced primary (LARC) and recurrent rectal cancer (LRRC), using outcomes achieved at highly specialised centres., Background Data: PE is established as the standard of care for selected patients with LARC and LRRC. There are currently no available benchmarks against which surgical performance in PE can be compared for audit and quality improvement., Methods: This international multicentre retrospective cohort study included patients undergoing PE for LARC or LRRC at 16 highly experienced centres between 2018 and 2023. Ten outcome benchmarks were established in a lower-risk subgroup. Benchmarks were defined by the 75th percentile of the results achieved at the individual centres., Results: 763 patients underwent PE, of which 464 patients (61%) had LARC and 299 (39%) had LRRC. 544 patients (71%) who met predefined lower risk criteria formed the benchmark cohort. For LARC patients, the calculated benchmark threshold for major complication rate was ≤44%; comprehensive complication index (CCI): ≤30.2; 30-day mortality rate: 0%; 90-day mortality rate: ≤4.3%; R0 resection rate: ≥79%. For LRRC patients, the calculated benchmark threshold for major complication rate was ≤53%; CCI: ≤34.1; 30-day mortality rate: 0%; 90-day mortality rate: ≤6%; R0 resection rate: ≥77%., Conclusions: The reported benchmarks for PE in patients with LARC and LRRC represent the best available care for this patient group globally and can be used for rigorous assessment of surgical quality and to facilitate quality improvement initiatives at international exenteration centres., Competing Interests: Conflicts of interest and disclosures: Julio Garcia-Aguilar disclosures - Ethicon (Professional Services and Activities) and Intuitive Surgical Inc. Equity (Professional Services and Activities)., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Abdominoperineal resection (APR) has been advocated for persistent or recurrent disease after failure of chemoradiation (CRT) for anal squamous cell cancer (SCC). Treatment with salvage APR can potentially achieve a cure. This study aimed to analyze oncological outcomes for salvage APR in a recent time period at a comprehensive cancer center. Methods: A retrospective review of all patients who underwent APR for biopsy-proven persistent or recurrent anal SCC between 1 January 2007 and 31 December 2020 was performed. Patients with stage IV disease at the time of initial diagnosis and patients with missing data were excluded. Univariate analysis was used with a chi-square test for categorical variables, and non-parametric tests were used for continuous variables. Kaplan-Meier survival analysis was performed to evaluate disease-specific (DSS), post-APR local recurrence-free (RFS), and disease-free survival (DFS). Results: A total of 96 patients were included in the analysis: 39 (41%) with persistent disease and 57 (59%) with recurrent SCC after chemoradiation had been completed. The median follow-up was 22 months (IQR 11-47). Forty-nine patients (51%) underwent extended APR and/or pelvic exenteration. Eight (8%) patients developed local recurrence, 30 (31%) developed local and distant recurrences, and 16 (17%) developed distant recurrences alone. The 3-year DSS, post-APR local recurrence-free survival, and disease-free survival were 53.8% (95% CI 43.5-66.5%), 54.5% (95% CI 44.4-66.8%), and 26.8% (95% CI 18.6-38.7%), respectively. In multivariate logistic regression analysis, positive microscopic margin (OR 10.0, 95% CI 2.16-46.12, p = 0.003), positive nodes in the surgical specimen (OR 9.19, 95% CI 1.99-42.52, p = 0.005), and lymphovascular invasion (OR 2.61 95% CI 1.05-6.51, p = 0.04) were associated with recurrence of disease. Gender, indication for APR (recurrent vs. persistent disease), HIV status, extent of surgery, or type of reconstruction did not influence survival outcomes. Twenty patients had targeted tumor-sequencing data available. Nine patients had PIK3CA mutations, seven of whom experienced a recurrence. Conclusions: Salvage APR for anal SCC after failed CRT was associated with poor disease-specific survival and low recurrence-free survival. Anal SCC patients undergoing salvage APR should be counseled that microscopic positive margins, positive lymph nodes, or the presence of lymphovascular invasion in the APR specimen are prognosticators for disease relapse. Our results accentuate the necessity for additional treatment strategies for the ongoing treatment challenge of persistent or recurrent anal SCC after failed CRT.

Background: The Memorial Sloan Kettering clinical calculator for estimating the likelihood of freedom from colon cancer recurrence on the basis of clinical and molecular variables was developed at a time when testing for microsatellite instability was performed selectively, based on patient age, family history, and histologic features. Microsatellite stability was assumed if no testing was done., Objective: This study aimed to validate the calculator in a cohort of patients who had all been tested for microsatellite instability., Design: Retrospective cohort analysis., Settings: Comprehensive cancer center., Patients: This study included consecutive patients who underwent curative resection for stage I, II, or III colon cancer between 2017 and 2019., Intervention: Universal testing of mircrosatellite phenotype in all cases., Main Outcome Measures: The calculator's predictive accuracy was assessed using the concordance index and a calibration plot of predicted versus actual freedom from recurrence at 3 years after surgery. For a secondary sensitivity analysis, the presence of a tumor deposit(s) (disease category N1c) was considered equivalent to one positive lymph node (category N1a)., Results: With a median follow-up of 32 months among survivors, the concordance index for the 745 patients in the cohort was 0.748 (95% CI, 0.693-0.801), and a plot of predicted versus observed recurrences approached the 45° diagonal, indicating good discrimination and calibration. In the secondary sensitivity analysis for tumor deposits, the concordance index was 0.755 (95% CI, 0.700-0.806)., Limitations: This study was limited by its retrospective, single-institution design., Conclusions: These results, based on inclusion of actual rather than imputed microsatellite stability status and presence of tumor deposits, confirm the predictive accuracy and reliability of the calculator. See Video Abstract ., Validacin De Una Calculadora Clnica Que Predice La Ausencia De Recurrencia Postquirurgica Del Cncer De Colon Sobre La Base De Variables Moleculares Y Clnicas: ANTECEDENTES:La calculadora clínica del Memorial Sloan Kettering para la estimación de la probabilidad de ausencia de recurrencia del cáncer de colon sobre la base de variables clínicas y moleculares, se desarrolló en un momento en que las pruebas para la inestabilidad de microsatélites se realizaban de forma selectiva, basadas en la edad del paciente, los antecedentes familiares y las características histológicas. Se asumía la estabilidad micro satelital si no se realizaba ninguna prueba.OBJETIVO:El objetivo de este estudio fue validar la calculadora en una cohorte de pacientes a los que se les había realizado la prueba de inestabilidad de microsatélites.DISEÑO:Análisis de cohorte retrospectivo.AJUSTE:Centro integral de cáncer.PACIENTES:Pacientes consecutivos con cáncer de colon que fueron sometidos a resección curativa por cáncer de colon en estadios I, II o III entre los años 2017 y 2019.PRINCIPALES MEDIDAS DE RESULTADO:La precisión predictiva de la calculadora fue evaluada mediante el índice de concordancia y un gráfico de calibración de la ausencia de recurrencia predecida versus la real a los 3 años tras la cirugía. A los efectos de un análisis secundario de sensibilidad, la presencia de depósito(s) tumoral(es) (categoría de enfermedad N1c) se consideró equivalente a un ganglio linfático positivo (categoría N1a).RESULTADOS:Con una mediana de seguimiento de 32 meses entre los supervivientes, el índice de concordancia para los 745 pacientes de la cohorte fue de 0,748 (intervalo de confianza del 95 %, 0,693 a 0,801), y una gráfica de recurrencias previstas versus observadas se acercó a la diagonal de 45°, indicando una buena discriminación y calibración. En el análisis secundario de sensibilidad para depósitos tumorales, el índice de concordancia fue de 0,755 (intervalo de confianza del 95 %, 0,700 a 0,806).LIMITACIONES:Diseño retrospectivo, institución única.CONCLUSIONES:Estos resultados, basados en la inclusión real del estado de estabilidad de microsatélites en lugar de imputado y la presencia de depósitos tumorales, confirman la precisión predictiva y la confiabilidad de la calculadora. (Traducción-Dr Osvaldo Gauto )., (Copyright © The ASCRS 2023.)

Colorectal cancer (CRC) cells show some alterations in lipid metabolism, including an increased fatty acid elongation. This study was focused on investigating the effect of a small interfering RNA (siRNA)-mediated decrease in fatty acid elongation on CRC cells' survival and migration. In our study, the elongase 4 ( ELOVL4 ) and elongase 6 ( ELOVL6 ) genes were observed to be highly overexpressed in both the CRC tissue obtained from patients and the CRC cells cultured in vitro (HT-29 and WiDr cell lines). The use of the siRNAs for ELOVL4 and ELOVL6 reduced cancer cell proliferation and migration rates. These findings indicate that the altered elongation process decreased the survival of CRC cells, and in the future, fatty acid elongases can be potentially good targets in novel CRC therapy.

Background: There is limited knowledge on long-term bowel, sexual, and urinary function after combined modality therapy for anal squamous-cell cancer., Objective: This study aimed to evaluate long-term changes in patients treated with combined modality., Design: This was a retrospective study of prospectively collected patient-reported outcome surveys., Setting: This study was conducted at a single institution., Patients: There were 143 patients with stage I to III anal cancer who were treated with chemoradiation and had completed the survey., Main Outcome Measures: This study included patient-reported outcomes reflecting bowel, sexual, and urinary function., Results: Thirty-nine percent of patients had major low anterior resection syndrome at baseline. Major low anterior resection syndrome remained stable (38%; 95% CI, 31%-46%) with no change over time (OR 0.95; 95% CI, 0.74-1.21; p = 0.7). Higher rates of major low anterior resection syndrome were observed for patients who had major low anterior resection syndrome at baseline (OR 20.7; 95% CI 4.70-91.3; p < 0.001) and for females (OR 2.14; 95% CI, 1.01-4.56; p = 0.047). On 5-point scales, we saw a nonsignificant increased level of sexual arousal during sexual activity after therapy for women (β for 1 year = 0.15; 95% CI, -0.01 to 0.32; p = 0.072) and nonsignificant decreased confidence in getting and keeping an erection after therapy for men (β for 1 year = -0.33; 95% CI, -0.66 to 0.00; p = 0.053)., Limitations: This was a single-institution study and only patients who answered the questionnaire were included in the study., Conclusions: A significant proportion of patients have major low anterior resection syndrome at baseline and after successful treatment for anal cancer. Having major low anterior resection syndrome at baseline was the biggest predictor of having major low anterior resection syndrome after treatment. Bowel, sexual, and urinary function did not improve over time up to 2 years after end of treatment. Physicians should counsel their patients before treatment that baseline poor bowel function is a risk factor for posttreatment bowel dysfunction. See Video Abstract at http://links.lww.com/DCR/C29 ., Evaluacin De Los Resultados Informados Por Los Pacientes Con Cncer Anal De Clulas Escamosas Que Se Someten a Una Terapia De Modalidad Combinada: ANTECEDENTES:Existe un conocimiento limitado sobre la función intestinal, sexual y urinaria a largo plazo después de la terapia de modalidad combinada para el cáncer anal de células escamosas.OBJETIVO:Evaluar los cambios a largo plazo en la función intestinal, sexual y urinaria en pacientes tratados con modalidad combinada.DISEÑO:Este fue un estudio retrospectivo de encuestas de resultados informadas por pacientes recolectadas prospectivamente.ESCENARIO:Institución única.PACIENTES:Fueron 143 pacientes con cáncer anal en estadio I-III que fueron tratados con quimiorradiación y completaron la encuesta.PRINCIPALES MEDIDAS DE RESULTADO:Resultados reportados por el paciente que reflejan la función intestinal, sexual, y urinaria.RESULTADOS:Treinta y nueve por ciento de los pacientes tenían puntajes importantes de síndrome de resección anterior bajo al inicio del estudio. Las puntuaciones del síndrome de resección anterior baja mayor permanecieron estables (38 %; IC del 95%: 31 %, 46 %) sin cambios con el tiempo (OR 0,95, IC del 95%: 0,74, 1,21, p = 0,7). Se observaron tasas más altas de puntuaciones del síndrome de resección anterior baja mayor para los pacientes que tenían puntuaciones del síndrome de resección anterior baja mayor desde el inicio (OR 20,7; IC del 95%: 4,70; 91,3, p < 0,001) y para las mujeres (OR 2,14; IC del 95%: 1,01, 4,56; p = 0,047). En escalas de 5 puntos, observamos un aumento no significativo del nivel de excitación sexual durante la actividad sexual después de la terapia para las mujeres (β durante 1 año = 0,15; IC del 95%: -0,01, 0,32; p = 0,072) y una disminución no significativa de la confianza en lograr y mantener una erección después de la terapia para hombres (β para 1 año = -0,33; IC del 95%: -0,66, 0,00; p = 0,053).LIMITACIONES:Este es un estudio de una sola institución. Solo se incluyeron en el estudio los pacientes que contestaron el cuestionario.CONCLUSIONES:Una proporción significativa de pacientes tienen puntajes de síndrome de resección anterior muy bajos al inicio del estudio y después de un tratamiento exitoso para el cáncer anal. Tener puntajes de síndrome de resección anterior bajos importantes al inicio del estudio fue el predictor más importante de tener puntajes de síndrome de resección anterior bajos importantes después del tratamiento. La función intestinal, sexual y urinaria no mejoró con el tiempo hasta 2 años después de finalizar el tratamiento. Los médicos deben aconsejar a sus pacientes antes del tratamiento que la mala función intestinal inicial es un factor de riesgo para la disfunción intestinal posterior al tratamiento. Consulte Video Resumen en http://links.lww.com/DCR/C29 . (Traducción-Dr. Yolanda Colorado )., (Copyright © The ASCRS 2022.)

Introduction: Radiation therapy (RT) for anorectal cancer after prior prostate cancer RT is usually avoided due to concern for complications. Data on this topic is scarce. Our aim was to evaluate tolerability, toxicity, and clinical outcomes associated with a second course of pelvic radiation in men with de novo anorectal cancers previously treated with RT for prostate cancer., Materials/methods: We conducted a single-institution retrospective study of men treated with RT for rectal or anal cancer after prior prostate RT. Toxicity data were collected. Treatment plans were extracted to assess doses to organs at risk and target coverage. Cumulative incidence was calculated for local and distant progression. Kaplan-Meier curves were used to estimate overall survival (OS) and progression-free survival (PFS)., Results: We identified 26 patients who received anorectal RT after prostate cancer RT: 17 for rectal cancer and 9 for anal cancer. None had metastatic disease. Prior prostate RT was delivered using low dose rate brachytherapy (LDR), external beam RT (EBRT), or EBRT + LDR. RT for rectal cancer was delivered most commonly using 50.4Gy/28 fractions (fr) or 1.5 Gy twice-daily to 30-45 Gy. The most used RT dose for anal cancer was 50Gy/25 fr. Median interval between prostate and anorectal RT was 12.3 years (range:0.5 - 25.3). 65% and 89% of rectal and anal cancer patients received concurrent chemotherapy, respectively. There were no reported ≥Grade 4 acute toxicities. Two patients developed fistulae; one was urinary-cutaneous after prostate LDR and 45Gy/25fr for rectal cancer, and the other was recto-vesicular after prostate LDR and 50Gy/25fr for anal cancer. In 11 patients with available dosimetry, coverage for anorectal cancers was adequate. With a median follow up of 84.4 months, 5-yr local progression and OS were 30% and 31% for rectal cancer, and 35% and 49% for anal cancer patients, respectively., Conclusion: RT for anorectal cancer after prior prostate cancer RT is feasible but should be delivered with caution since it poses a risk of fistulae and possibly bleeding, especially in patients treated with prior LDR brachytherapy. Further studies, perhaps using proton therapy and/or rectal hydrogel spacers, are needed to further decrease toxicity and improve outcomes., Competing Interests: PR reports prior research funding from and is a consultant for EMD Serono. MJZ is a consultant for Boston Scientific. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Hilal, Wu, Reyngold, Cuaron, Navilio, Romesser, Dreyfuss, Yin, Zhang, Bai, Berry, Zinovoy, Nusrat, Pappou, Zelefsky, Crane and Hajj.)

Purpose: Prospective data on the efficacy of a watch-and-wait strategy to achieve organ preservation in patients with locally advanced rectal cancer treated with total neoadjuvant therapy are limited., Methods: In this prospective, randomized phase II trial, we assessed the outcomes of 324 patients with stage II or III rectal adenocarcinoma treated with induction chemotherapy followed by chemoradiotherapy (INCT-CRT) or chemoradiotherapy followed by consolidation chemotherapy (CRT-CNCT) and either total mesorectal excision (TME) or watch-and-wait on the basis of tumor response. Patients in both groups received 4 months of infusional fluorouracil-leucovorin-oxaliplatin or capecitabine-oxaliplatin and 5,000 to 5,600 cGy of radiation combined with either continuous infusion fluorouracil or capecitabine during radiotherapy. The trial was designed as two stand-alone studies with disease-free survival (DFS) as the primary end point for both groups, with a comparison to a null hypothesis on the basis of historical data. The secondary end point was TME-free survival., Results: Median follow-up was 3 years. Three-year DFS was 76% (95% CI, 69 to 84) for the INCT-CRT group and 76% (95% CI, 69 to 83) for the CRT-CNCT group, in line with the 3-year DFS rate (75%) observed historically. Three-year TME-free survival was 41% (95% CI, 33 to 50) in the INCT-CRT group and 53% (95% CI, 45 to 62) in the CRT-CNCT group. No differences were found between groups in local recurrence-free survival, distant metastasis-free survival, or overall survival. Patients who underwent TME after restaging and patients who underwent TME after regrowth had similar DFS rates., Conclusion: Organ preservation is achievable in half of the patients with rectal cancer treated with total neoadjuvant therapy, without an apparent detriment in survival, compared with historical controls treated with chemoradiotherapy, TME, and postoperative chemotherapy.

Background: Current guidelines recommend restaging with MRI after neoadjuvant therapy for rectal cancer, but the accuracy of restaging MRI in estimating circumferential margin involvement requires additional clarification., Objective: The objective of this study was to measure the accuracy of circumferential resection margin assessment by MRI after neoadjuvant therapy and identify characteristics associated with accuracy., Design: MRI data were retrospectively analyzed for concordance with the findings of whole-mount pathology analysis of the corresponding surgical specimens. Univariate and multivariate logistic regression analyses were performed to identify characteristics associated with accuracy., Setting: This study was conducted at a comprehensive cancer center., Patients: Included in the study were consecutive patients who underwent total mesorectal excision for rectal cancer between January 2018 and March 2020 after receiving neoadjuvant therapy and undergoing restaging with MRI., Main Outcome Measures: The primary outcome of this study included accuracy, sensitivity, specificity, and positive and negative predictive values for categorizing the circumferential resection margin as threatened; mean and paired mean differences were in proximity of the margin., Results: Of the 94 patients included in the analysis, 39 (41%) had a threatened circumferential resection margin according to MRI at restaging, but only 17 (18%) had a threatened margin based on pathology. The accuracy of MRI in identifying a threatened margin was 63.8%, with margin proximity overestimated by 0.4 cm on average. In multivariate logistic regression, anterior location of the margin and tumor proximity to the anal verge were independently associated with reduced MRI accuracy., Limitations: A limitation was the retrospective design at a single institution., Conclusions: The knowledge that MRI-based restaging after neoadjuvant therapy overestimates circumferential margin proximity may render some surgical radicality unnecessary and thereby help avoid the associated morbidity. With the recognition that MRI-based assessment of margin proximity may not be reliable for anterior margin and for distal tumors, radiologists may want to use greater caution in interpreting images of tumors with these characteristics and to acknowledge the uncertainty in their reports. See Video Abstract at http://links.lww.com/DCR/B814., La Irm En La Reestadificacin Luego De Terapia Neoadyuvante En El Cncer De Recto Sobrestima La Proximidad Del Margen De Reseccin Circunferencial Segn Lo Determinado Comparativamente Con La Pieza De Anatomopatologa: ANTECEDENTES:Las pautas actuales recomiendan la re-estadificación por medio de la resonancia magnética luego de terapia neoadyuvante en los casos de cáncer de recto, pero la precisión de la reevaluación con la IRM para estimar el grado de implicación del margen circunferencial requiere aclaraciones adicionales.OBJETIVO:Medir el grado de exactitud en la evaluación del margen de resección circunferencial mediante resonancia magnética después de la terapia neoadyuvante e identificar las características asociadas con la precisión.DISEÑO:Se analizaron retrospectivamente los datos de resonancia magnética para determinar la concordancia entre los hallazgos del análisis de la pieza de anatamopatología y las muestras quirúrgicas correspondientes. Se realizó el análisis de regresión logística univariada y multivariada para identificar las características asociadas con la exactitud.AJUSTE:Centro oncológico integral.PACIENTES:Todos aquellos que se sometieron consecutivamente a una excisión total del mesorrecto por cáncer rectal entre Enero 2018 y Febrero 2020 luego de recibir terapia neoadyuvante y someterse a una re-estadificación por imágenes de resonancia magnética (IRM).PRINCIPALES MEDIDAS DE RESULTADO:La exactitud, la sensibilidad y especificidad; los valores predictivos positivos y negativos para categorizar el margen de resección circunferencial como amenazado; la diferencia media y las medias pareadas de proximidad a los margenes.RESULTADOS:De los 94 pacientes incluidos en el análisis, 39 (41%) tenían un margen de resección circunferencial amenazado según la resonancia magnética en la re-estadificación, pero solo 17 (18%) tenían un margen amenazado basado en la patología. La precisión de la resonancia magnética para identificar un margen amenazado fue del 63,8%, con la proximidad del margen sobreestimada en 0,4 cm en promedio. En la regresión logística multivariada, la ubicación anterior de los bordes de resección y la proximidad del tumor al margen anal se asociaron de forma independiente con la reducción en la precisión de la resonancia magnética.LIMITACIONES:Diseño retrospectivo en una institución única.CONCLUSIONES:El saber que la re-estadificación basada en la IRM, luego de terapia neoadyuvante sobreestima la proximidad de la lesión a los márgenes circunferenciales, hace innecesaria cierta radicalidad quirúrgica complementaria, lo que ayuda a evitar morbilidad asociada. Reconociendo que la evaluación de proximidad de los márgenes de resección basada en la resonancia magnética, no puede ser confiable en casos de márgenes anteriores y en casos de tumores distales. Los radiólogos recomiendan tener más precaución en la interpretación de imágenes de tumores con estas características y reconocen cierto desasosiego en sus informes. Consulte Video Resumen en http://links.lww.com/DCR/B814., (Copyright © The ASCRS 2021.)

Purpose: Pelvic radiation therapy (RT) is standard of care for patients with locally advanced rectal cancer (LARC). Premature ovarian insufficiency (POI) in premenopausal women is a possible side effect. The purpose of our study was to evaluate factors associated with POI in women younger than 50 years, treated with pelvic RT for LARC, including those who underwent ovarian transposition (OT)., Methods and Materials: We retrospectively reviewed the records of women younger than 50 years treated with pelvic RT for LARC at our institution between 2001 and 2019. Clinical and hormonal data were used to determine ovarian function. The ovaries and uterus were contoured and dose volume histograms were generated. Association of clinical and dosimetric factors with POI within 12 months of RT was evaluated using Wilcoxon-rank sum test and Fisher's exact test., Results: We identified 76 premenopausal women at time of RT with median age of 43 years (range, 20-49). Twenty-six women (34%) underwent OT. Neoadjuvant, concurrent, and adjuvant chemotherapy was administered in 56 (74%), 69 (91%), and 26 (34%) women, respectively. Median RT dose was 50 Gy/25 fractions. Among 75 women with 12 months of follow-up, 25% had preservation of ovarian function, all in the OT group. Ovarian function was preserved in 19 (76%) women who underwent OT. The median of ovarian mean dose was 1.7 Gy in the OT group versus 44.8 Gy in the non-OT group ( P < .001). OT and age at RT were significantly associated with POI ( P < .001). No patient with ovarian mean dose less than 1.36 Gy developed POI., Conclusions: OT was significantly associated with reduced risk of POI by enabling lower radiation doses to the ovaries. OT should be considered in young patients undergoing pelvic RT. Although there appears to be a significant association between ovarian mean dose and POI, larger studies are needed to find a dosimetric threshold. Our results suggest keeping the dose to the ovaries as low as reasonably achievable in patients who undergo OT and pelvic RT., (© 2021 The Author(s).)

Tumor infiltrating lymphocytes (TIL), which represent host adaptive response to the tumor, were first identified at scanning magnification to select areas with the highest counts on hematoxylin and eosin slides, quantitated per high-power field (HPF), and analyzed for association with recurrence-free survival (RFS) in 848 patients. Highest TIL in a single HPF was analyzed as a continuous and categorical variable, and optimal cutoff analysis was performed to predict RFS. Highest TIL count in a single HPF ranged from 0 to 45, and the optimal cutoff for TIL high vs TIL low was determined to be ≥ 3 vs < 3 with a concordance probability estimate of 0.74. In the entire cohort, 5-year RFS was 90.2% (95% CI = 83.7-94.2) in TIL high compared to 78.9% (95% CI = 74.1-82.9) in TIL low (log rank P < .0001). TIL remained significant in the mismatch repair-proficient (pMMR) cohort where 5-year RFS was 94.6% (95% CI = 88.3-97.5) in TIL high compared to 77.9% (95% CI = 69.2-84.4) in TIL low ( P = .008). On multivariable analysis, TIL and AJCC Stage were independently associated with RFS in the pMMR cohort. Qualitatively in the pMMR cohort, RFS in Stage II TIL high patients was similar to that in Stage I patients and RFS in Stage III TIL high was similar to that in Stage II TIL low patients. Assessment of TIL in a single HPF using standard H&E slides provides important prognostic information independent of MMR status and AJCC stage., (© 2020 The Author(s). Published with license by Taylor & Francis Group, LLC.)

Rectal cancer (RC) is a challenging disease to treat that requires chemotherapy, radiation and surgery to optimize outcomes for individual patients. No accurate model of RC exists to answer fundamental research questions relevant to patients. We established a biorepository of 65 patient-derived RC organoid cultures (tumoroids) from patients with primary, metastatic or recurrent disease. RC tumoroids retained molecular features of the tumors from which they were derived, and their ex vivo responses to clinically relevant chemotherapy and radiation treatment correlated with the clinical responses noted in individual patients' tumors. Upon engraftment into murine rectal mucosa, human RC tumoroids gave rise to invasive RC followed by metastasis to lung and liver. Importantly, engrafted tumors displayed the heterogenous sensitivity to chemotherapy observed clinically. Thus, the biology and drug sensitivity of RC clinical isolates can be efficiently interrogated using an organoid-based, ex vivo platform coupled with in vivo endoluminal propagation in animals.

Background: Increasing the interval from completion of neoadjuvant therapy to surgery beyond 8 weeks is associated with increased response of rectal cancer to neoadjuvant therapy. However, reports are conflicting on whether extending the time to surgery is associated with increased perioperative morbidity., Methods: Patients who presented with a tumor within 15 cm of the anal verge in 2009-2015 were grouped according to the interval between completion of neoadjuvant therapy and surgery: < 8 weeks, 8-12 weeks, and 12-16 weeks., Results: Among 607 patients, the surgery was performed at < 8 weeks in 317 patients, 8-12 weeks in 229 patients, and 12-16 weeks in 61 patients. Patients who underwent surgery at 8-12 weeks and patients who underwent surgery at < 8 weeks had comparable rates of complications (37% and 44%, respectively). Univariable analysis identified male sex, earlier date of diagnosis, tumor location within 5 cm of the anal verge, open operative approach, abdominoperineal resection, and use of neoadjuvant chemoradiotherapy alone to be associated with higher rates of complications. In multivariable analysis, male sex, tumor location within 5 cm of the anal verge, open operative approach, and neoadjuvant chemoradiotherapy administered alone were independently associated with the presence of a complication. The interval between neoadjuvant therapy and surgery was not an independent predictor of postoperative complications., Conclusions: Delaying surgery beyond 8 weeks from completion of neoadjuvant therapy does not appear to increase surgical morbidity in rectal cancer patients.

Background: The Memorial Sloan Kettering Cancer Center (MSK) colon cancer recurrence nomogram is a risk calculator that provides patients and clinicians with individualized prediction of recurrence following curative resection of colon cancer. Although validated on multiple separate cohorts, the nomogram requires periodic updating as patient care changes over time. The aim of this study was to evaluate the nomogram's accuracy in a contemporary cohort and modify the tool to reflect improvements in outcome related to advances in colon cancer therapy., Methods: A contemporary patient cohort was compiled, including consecutive colon cancer patients undergoing curative resection for stage I-III colon adenocarcinoma at MSK from 2007 to 2014. The nomogram's predictive accuracy was assessed by concordance index and calibration plots of predicted vs actual freedom from recurrence at 5 years after surgery., Results: Data from a total of 999 eligible patients with complete records were used for validation. Median follow-up among survivors was 37 months. The concordance index was 0.756 (95% confidence interval = 0.707 to 0.805), indicating continued discriminating power, but the calibration plot revealed that the nomogram overestimated recurrence risk. Recalibration of the nomogram by estimating a new baseline freedom-from-recurrence function restored the nomogram's accuracy., Conclusion: The updated nomogram retains the original nomogram's variables but includes a lower baseline estimation of recurrence risk, reflecting improvements in outcomes for all stages of colon cancer, likely resulting from advances in imaging and integration of multiple treatment modalities.

Background: The use of the da Vinci robotic platform for total colectomy has been limited by the need to reposition the patient-side surgical cart from one side of the patient to the other, which increases operative time. In this study, we examined the feasibility of robotic total colectomy using the da Vinci Xi model, which offers a rotating boom-mounted system and laser-targeted trocar positioning., Methods: The study cohort consisted of 23 patients who underwent minimally invasive total colectomy for cancer or polyposis syndromes at a comprehensive cancer center between 2015 and 2017. Of the 23 colectomies, 15 were robotic and eight were laparoscopic. For the robotic colectomies, trocars were placed in the supraumbilical region and all four quadrants. The da Vinci Xi robot was placed between the patient's legs, and the boom was rotated from left to right and then to the middle in order to work sequentially on the right colon, the left colon, and the pelvis. Operating time and short-term outcomes were compared between the patients who underwent robotic surgery and the patients who underwent laparoscopic surgery., Results: The two groups of patients were comparable in age, gender, BMI, physical status, and disease types. In the robotic group, median length of stay (4 vs. 6 days, p = 0.047) was significantly shorter and median operative time (243 vs. 263 min, p = 0.97) and median estimated blood loss (50 vs. 100 ml; p = 0.08) were similar between the groups., Conclusions: With the da Vinci Xi boom-mounted system, total abdominal colectomy can be performed without the need to move the patient-side surgical cart and is associated with shorter length of stay and similar operative time compared to the laparoscopic approach.

Background: Surgical site infections (SSIs) are a major cause of morbidity, mortality, and healthcare costs, and patients undergoing simultaneous colorectal/liver resections are at an especially high SSI risk., Methods: Data were collected on all patients undergoing synchronous colorectal/liver resection from 2011 to 2016 (n = 424). The intervention, implemented in 2013, included 13 multidisciplinary perioperative components. The primary endpoints were superficial/deep and organ space SSIs. Secondary endpoints were hospital length of stay (LOS) and 30-day readmission rate. To control for changes in SSI rates independent of the intervention, interrupted time series analysis was conducted., Results: Overall, superficial/deep, and organ space SSIs decreased by 60.5% (p < 0.001), 80.6% (p < 0.001), and 47.6% (p = 0.008), respectively. In the pre-intervention cohort (n = 231), there were 79 (34.2%), 31 (13.4%), and 48 (20.8%) total, superficial/deep, and organs space SSIs, respectively. In the post-intervention cohort (n = 193), there were 26 (13.5%), 5 (2.6%), and 21 (10.9%) total, superficial/deep, and organs space SSIs, respectively. Median LOS decreased from 9 to 8 days (p < 0.001). Readmission rates did not change (p = 0.6). Interrupted time series analysis found no significant trends in SSI rate within the pre-intervention (p = 0.35) and post-intervention (p = 0.55) periods., Conclusion: In combined colorectal/liver resection patients, implementation of a multidisciplinary care bundle was associated with a 61% reduction in SSIs, with the greatest impact on superficial/deep SSI, and modest reduction in LOS. The absence of trends within each time period indicated that the intervention was likely responsible for SSI reduction. Future efforts should target further reduction in organ space SSI., (Copyright © 2018. Published by Elsevier Ltd.)

Background: Relationships between high-volume surgeons and improved postoperative outcomes have been well documented. Colorectal procedures are often performed by general surgeons, particularly in emergent settings, and may form a large component of their practice. The influence of subspecialized training on outcomes after emergent colon surgery, however, is not well described., Objective: The purpose of this study was to determine whether subspecialty training in colorectal surgery is associated with differences in postoperative outcomes after emergency colectomy., Design: This was a retrospective cohort study., Settings: Three tertiary care hospitals participating in the National Surgical Quality Improvement Project were included., Patients: Patients undergoing emergent colon resections were identified at each institution and stratified by involvement of either a colorectal surgeon or a general or acute care surgeon., Main Outcome Measures: Propensity score matching was used to isolate the effect of surgeon specialty on the primary outcomes, including postoperative morbidity, mortality, length of stay, and the need for unplanned major reoperation, in comparable cohorts of patients., Results: A total of 889 cases were identified, including 592 by colorectal and 297 by general/acute care surgeons. After propensity score matching, cases performed by colorectal surgeons were associated with significantly lower rates of 30-day mortality (6.7% vs 16.4%; p = 0.001), postoperative morbidity (45.0% vs 56.7%; p = 0.009), and unplanned major reoperation (9.7% vs 16.4%; p = 0.04). In addition, length of stay was ≈4.4 days longer among patients undergoing surgery by general/acute care surgeons (p < 0.001)., Limitations: This study was limited by its retrospective design, with potential selection bias attributed to referral patterns., Conclusions: After controlling for underlying disease states and illness severity, emergent colon resections performed by colorectal surgeons were associated with significantly lower rates of postoperative morbidity and mortality when compared with noncolorectal surgeons. These findings may have implications for referral patterns for institutions. See Video Abstract at http://links.lww.com/DCR/A767.

Targeted delivery of chemotherapeutics in order to overcome side effects and enhance chemosensitivity remains a major issue in cancer research. In this context, biocompatible oil-in-water (O/W) microemulsions were developed as matrices for the encapsulation of DPS-2 a benzothiophene analogue, exhibiting high cytotoxicity in various cancer cell lines, among them the MW 164 skin melanoma and Caco-2 human epithelial colorectal adenocarcinoma cell lines. The microemulsion delivery system was structurally characterized by dynamic light scattering (DLS) and electron paramagnetic resonance (EPR) spectroscopy. The effective release of a lipophilic encapsulated compound was evaluated via confocal microscopy. The cytotoxic effect, in the presence and absence of DPS-2, was examined through the thiazolyl blue tetrazolium bromide (MTT) cell proliferation assay. When encapsulated, DPS-2 was as cytotoxic as when dissolved in dimethyl sulfoxide (DMSO). Hence, the oil cores of O/W microemulsions were proven effective biocompatible carriers of lipophilic bioactive molecules in biological assessment experiments. Further investigation through fluorescence-activated cell sorting (FACS) analysis, comet assay, and Western blotting, revealed that DPS-2, although non-genotoxic, induced S phase delay accompanied by cdc25A degradation and a nonapoptotic cell death in both cell lines, which implies that this benzothiophene analogue is a deoxyribonucleic acid (DNA) replication inhibitor.

Mesenchymal stem cells (MSCs) are a population of cells harboring in many tissues with the ability to differentiate toward many different lineages. Unraveling the molecular profile of MSCs is of great importance due to the fact that these cells are very often used in preclinical and clinical studies. We have previously reported the expression of insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1) an oncofetal mRNA-binding protein-in different stem cell types such as bone marrow (BM)-MSC and umbilical cord blood (UCB)-hematopoietic stem cells. Here, we demonstrate that MSCs of adipose tissue, BM, and UC origin have a differential pattern of IGF2BP1 and ten-eleven-translocate 1/2 (TET1/2) expression that could correlate with their proliferation potential. Upon IGF2BP1 interference, a significant reduction of cell proliferation is observed, accompanied by reduced expression of c-MYC and GLI1 and increased p21. We also present, for the first time, evidence that IGF2BP1 is epigenetically regulated by TET1 and TET2 demethylases. Specifically, we show that TET1 directly binds to the promoter of IGF2BP1 gene and affects the hydroxymethylation status of its promoter. These results indicate that IGF2BP1 and TET1/2 contribute to the stemness of MSCs, at least regarding their proliferative potential.

Reversal of promoter DNA hypermethylation and associated gene silencing is an attractive cancer therapy approach. The DNA methylation inhibitors decitabine and azacitidine are efficacious for hematological neoplasms at lower, less toxic, doses. Experimentally, high doses induce rapid DNA damage and cytotoxicity, which do not explain the prolonged time to response observed in patients. We show that transient exposure of cultured and primary leukemic and epithelial tumor cells to clinically relevant nanomolar doses, without causing immediate cytotoxicity, produce an antitumor "memory" response, including inhibition of subpopulations of cancer stem-like cells. These effects are accompanied by sustained decreases in genomewide promoter DNA methylation, gene reexpression, and antitumor changes in key cellular regulatory pathways. Low-dose decitabine and azacitidine may have broad applicability for cancer management., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Mesenchymal stem cells (MSCs) can contribute to tissue repair by actively migrating to sites of tissue injury. However, the cellular and molecular mechanisms of MSC recruitment are largely unknown. The nuclear factor (NF)-kappaB pathway plays a pivotal role in regulating genes that influence cell migration, cell differentiation, inflammation, and proliferation. One of the major cytokines released at sites of injury is tumor necrosis factor-alpha (TNF-alpha), which is known to be a key regulator of the NF-kappaB pathway. Therefore, we hypothesized that TNF-alpha may lead to MSC invasion and proliferation by activation of the NF-kappaB pathway. TNF-receptor 1 and 2, NF-kappaB (p65), and IkappaB kinase 2 (IKK-2) are expressed in human MSCs (hMSCs). Stimulation of hMSCs with TNF-alpha caused a p65 translocation from the cytoplasm to nucleoplasm but did not change the expression profile of MSC markers. TNF-alpha strongly augmented the migration of hMSCs through the human extracellular matrix. Using lentiviral gene transfer, overexpressing a dominant-negative mutant of IKK-2 (dn-IKK-2) significantly blocked this effect. NF-kappaB target genes associated with migration (vascular cell adhesion molecule-1, CD44, and matrix metalloproteinase 9) were upregulated by TNF-alpha stimulation and blocked by dn-IKK-2. Moreover, using the bromodeoxyuridine assay, we showed that the inhibition of the NF-kappaB pathway caused a significant reduction in the basal proliferation rate. TNF-alpha stimulated the proliferation of hMSCs, whereas overexpression of dn-IKK-2 significantly blocked this effect. TNF-alpha led to the upregulated expression of the proliferation-associated gene cyclin D1. In conclusion, we demonstrated that the NF-kappaB pathway components, p65 and IKK-2, are expressed in hMSCs. Our data provide evidence that this signal transduction pathway is implicated in TNF-alpha-mediated invasion and proliferation of hMSCs. Therefore, hMSC recruitment to sites of tissue injury may, at least in part, be regulated by the NF-kappaB signal transduction pathway.