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Constraints of pelvic anatomy render complete cytoreduction (CRS) challenging. The aim of this study is to investigate the impact of pelvic peritonectomy during CRS/HIPEC on colorectal peritoneal metastasis (CRPM) patients' outcomes.This is a retrospective analysis of a prospectively maintained CRS/hyperthermic intraperitoneal chemotherapy (HIPEC) database. The analysis included 217 patients with CRPM who had a CRS/HIPEC between 2014 and 2021. We compared perioperative and oncological outcomes of patients with pelvic peritonectomy (PP) (n = 63) to no pelvic peritonectomy (non-PP) (n = 154).No differences in demographics were identified. The peritoneal cancer index (PCI) was higher in the PP group with a median PCI of 12 vs. 6 in the non-PP group (p 0.001). Operative time was 4.9 vs. 4.3 h in the PP and non-PP groups, respectively (p = 0.63). Median hospitalization was longer in the PP group at 12 vs. 10 days (p = 0.007), and the rate of complications were higher in the PP group at 57.1% vs. 39.6% (p = 0.018). Pelvic peritonectomy was associated with worse disease-free (DFS) and overall survival (OS) with 3-year DFS and OS of 7.3 and 46.3% in the PP group vs. 28.2 and 87.8% in the non-PP group (p = 0.028, p . 0.001). The univariate OS analysis identified higher PCI (p = 0.05), longer surgery duration (p = 0.02), and pelvic peritonectomy (p 0.001) with worse OS. Pelvic peritonectomy remained an independent prognostic variable, irrespective of PCI, on the multivariate analysis (p 0.001).Pelvic peritonectomy at the time of CRS/HIPEC is associated with higher morbidity and worse oncological outcomes. These findings should be taken into consideration in the management of patients with pelvic involvement.

An increasing proportion of elderly patients (EP) are undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy (CRS/HIPEC). They have increased comorbidities and perioperative risk. Current literature is deficient in describing the outcomes of EP undergoing CRS/HIPEC.A retrospective review of our prospectively maintained CRS/HIPEC database analyzed perioperative and oncological outcomes of EP (70 y) compared to younger patients (YP) (60 y).Of 500 CRS/HIPEC patients, 62 EP and 210 YP were included. Median age was 73 y in EP and 46 y in YP. Demographic, clinical, operative, and perioperative outcomes were similar between groups. American Society of Anesthesiologists 3 was more prevalent in the EP with 88.2% versus 54.8% in the YP (P 0.001). Comorbidities were higher in the EP with 87.1% versus 39.0% in the YP (P 0.001). Peritoneal Cancer Index score was similar with a median of 9. All postoperative and severe complications were similar with 55.2% and 17.1% in the YP and 64.5% and 21.0% in the EP (P = 0.242; P = 0.448). Postoperative mortality was similar with 1.5% in the YP and 5.0% in the EP (P = 0.134). In colorectal primary patients, median overall and disease-free survival was 61.8 and 12.9 mo in the YP and 64.6 and 11.3 mo in the EP (P = 0.363; P = 0.845).Despite a significant age difference, increased comorbidities, worse American Society of Anesthesiologists, and similar Peritoneal Cancer Index burden, we found no significant differences in perioperative complications or oncological benefit in elderly CRS/HIPEC patients. EP appear to have similar perioperative and oncological outcomes as YP.

Cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) have demonstrated benefit in patients with colorectal peritoneal metastases (CRPM). Traditionally, extraperitoneal disease is considered a contraindication to CRS/HIPEC. Stable lung metastases in patients with colorectal cancer often have an indolent course, while the presence of untreated peritoneal metastases poorly affects short-term survival. We sought to evaluate the outcomes of patients undergoing CRS/HIPEC for peritoneal disease with known stable lung metastases.We retrospectively reviewed our prospectively maintained CRS/HIPEC database. In 2017, we adopted a policy of considering patients with stable lung metastases for CRS/HIPEC as part of multidisciplinary treatment. We compared the oncologic outcome and safety of CRS/HIPEC with peritoneal only (PM) against patients with peritoneal and lung metastases (PLM).Our database includes 570 patients with CRS/HIPEC of which 174 with CRPM that underwent CRS/HIPEC, 18 with preoperatively diagnosed peritoneal and lung metastases. The demographics of the PM and PLM group were similar with the exception of operative time that was longer in the PLM group. Median PCI of the cohort was 7, similar in both groups (p = 0.89). Three-year overall survival (OS) of PLM patients was 68%, compared to 71% in PM (p = 0.277). Three-year progression-free survival (PFS) rate was 20% in PLM and 23% in PM (p = 0.688).Presence of stable lung metastases from colorectal cancer in patients with CRPM does not appear to affect the outcomes of CRS/HIPEC. Patients with stable lung disease should be considered for CRS/HIPEC after multidisciplinary discussion.

Identifying colorectal cancer patient populations responsive to chemotherapy or chemoradiation therapy before surgery remains a challenge. Recently validated mouse protocols for organoid irradiation employ the single hit multi-target (SHMT) algorithm, which yields a single value, the D0, as a measure of inherent tissue radiosensitivity. Here, we translate these protocols to human tissue to evaluate radioresponsiveness of patient-derived organoids (PDO) generated from normal human intestines and rectal tumors of patients undergoing neoadjuvant therapy. While PDOs from adenomas with a logarithmically expanded Lgr5+ intestinal stem cell population retain the radioresistant phenotype of normal colorectal PDOs, malignant transformation yields PDOs from a large patient subpopulation displaying marked radiosensitivity due to reduced homologous recombination–mediated DNA repair. A proof-of-principle pilot clinical trial demonstrated that rectal cancer patient responses to neoadjuvant chemoradiation, including complete response, correlate closely with their PDO D0 values. Overall, upon transformation to colorectal adenocarcinoma, broad radiation sensitivity occurs in a large subset of patients that can be identified using SHMT analysis of PDO radiation responses.Significance:Analysis of inherent tissue radiosensitivity of patient-derived organoids may provide a readout predictive of neoadjuvant therapy response to radiation in rectal cancer, potentially allowing pretreatment stratification of patients likely to benefit from this approach.

Tissue survival responses to ionizing radiation are nonlinear with dose, rather yielding tissue-specific descending curves that impede straightforward analysis of biologic effects. Apoptotic cell death often occurs at low doses, while at clinically relevant intermediate doses, double-strand break misrepair yields mitotic death that determines outcome. As researchers frequently use a single low dose for experimentation, such strategies may inaccurately depict inherent tissue responses. Cutting edge radiobiology has adopted full dose survival profiling and devised mathematical algorithms to fit curves to observed data to generate highly reproducible numerical data that accurately define clinically relevant inherent radiosensitivities. Here, we established a protocol for irradiating organoids that delivers radiation profiles simulating the organ of origin. This technique yielded highly similar dose–survival curves of small and large intestinal crypts in vivo and their cognate organoids analyzed by the single-hit multi-target (SHMT) algorithm, outcomes reflecting the inherent radiation profile of their respective Lgr5+ stem cell populations. As this technological advance is quantitative, it will be useful for accurate evaluation of intestinal (patho)physiology and drug screening.Significance:These findings establish standards for irradiating organoids that deliver radiation profiles that phenocopy the organ of origin.See related commentary by Muschel et al., p. 927

Supplementary Data from Colorectal Cancer Develops Inherent Radiosensitivity That Can Be Predicted Using Patient-Derived Organoids

Supplementary Materials. Table S1. List of all reagents used in this study; Figure S1. LI organoids regrow after radiation; Figure S2. Sorting strategy for intestinal stem cells from the small and large intestines; Figure S3. Flow cytometry analysis of GFP+ cells in organoids versus colonies; Figure S4. Day 1 post-plating colonic stem cell colonies display defective DNA repair.

Identifying colorectal cancer patient populations responsive to chemotherapy or chemoradiation therapy before surgery remains a challenge. Recently validated mouse protocols for organoid irradiation employ the single hit multi-target (SHMT) algorithm, which yields a single value, the D0, as a measure of inherent tissue radiosensitivity. Here, we translate these protocols to human tissue to evaluate radioresponsiveness of patient-derived organoids (PDO) generated from normal human intestines and rectal tumors of patients undergoing neoadjuvant therapy. While PDOs from adenomas with a logarithmically expanded Lgr5+ intestinal stem cell population retain the radioresistant phenotype of normal colorectal PDOs, malignant transformation yields PDOs from a large patient subpopulation displaying marked radiosensitivity due to reduced homologous recombination–mediated DNA repair. A proof-of-principle pilot clinical trial demonstrated that rectal cancer patient responses to neoadjuvant chemoradiation, including complete response, correlate closely with their PDO D0 values. Overall, upon transformation to colorectal adenocarcinoma, broad radiation sensitivity occurs in a large subset of patients that can be identified using SHMT analysis of PDO radiation responses. Significance: Analysis of inherent tissue radiosensitivity of patient-derived organoids may provide a readout predictive of neoadjuvant therapy response to radiation in rectal cancer, potentially allowing pretreatment stratification of patients likely to benefit from this approach.

Background Gastrointestinal (GI) leaks after cytoreductive surgery and hyperthermic Intraperitoneal Chemotherapy (CRS/HIPEC) is a known life-threatening complication that may alter patients’ outcomes. Our aim is to investigate risk factors associated with GI leaks and evaluate the impact of GI leaks on patient’s oncological outcomes. Methods A retrospective analysis of perioperative and oncological outcomes of patients with and without GI leaks after CRS/HIPEC. Results Out of 191 patients included in this study, GI leaks were identified in 17.8% (34/191) of patients. Small bowel anastomoses were the most common site (44%). Most of the GI leaks were managed conservatively and re-operation was needed in 44.1% of cases. Univariate analysis identified higher PCI (p = 0.03), higher number of packed cells transfused (p = 0.036), pelvic peritonectomy (p = 0.013), high number of anastomoses (p = 0.003) and colonic resection (p = 0.042) as factors associated with GI leaks. Multivariate analysis identified stapled anastomoses (OR 2.59, p = 0.001) and pelvic peritonectomy (OR 2.33, p = 0.044) as independent factors associated with GI leaks. Disease-free survival tended to be worse in the leak group but did not reach statistical significance (p = 0.235). The 3- and 5-year OS was 73.2% and 52.9% in the leak group compared to 75.8% and 73.2% in the non-leak group (p = 0.236). Conclusions GI leak showed no impact on overall and disease free survival after CRS/HIPEC.Avoidance of stapled reconstruction in high risk patients with high tumor burden and large number of anastomoses may yield improved outcomes.

Peritoneal Cancer Index (PCI) and complete cytoreduction are the best outcome predictors following cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). Lesions in critical areas, regardless of PCI, complicate surgery and impact oncological outcomes. We prospectively defined "Critical lesions" (CL) as penetrating the hepatic hilum, diaphragm at hepatic outflow, major blood vessels, pancreas, or urinary tract.Retrospective analysis of a prospective database of 352 CRS + HIPEC patients from 2015 to 2019. Excluded patients with aborted/redo operation (n = 112), or incomplete data (n = 19). Patients categorized by CL status and compared: operative time, estimated blood loss (EBL), PCI, transfusions, hospital stay, post-operative complications and mortality, overall survival (OS) and disease-free survival (DFS).Included 221 patients (78 CL; 143 no-CL). No difference in patients' characteristics: age, BMI, gender or co-morbidities noted. Operative time longer (5.3 h vs 4.3 h, p 0.01), EBL higher (769 ml vs 405 ml, p 0.01), transfusions higher (1.9 vs 0.7 Units, p 0.001) and PCI higher (15.5 vs 9.5, p 0.01) in CL. No difference in major complications. Postoperative complications, CL, OR-time and transfusions were predictive of OS in univariate analysis, while only complications remained on multivariate analysis. Median follow up of 21.4 months, 3-year DFS/OS was 22% vs 30% (p 0.037) and 73% vs 87% (p 0.014) in CL and non-CL, respectively. Despite CL complete resection, 17/38 patients (44.7%) that recurred had recurrence at previous CL site.Critical lesions complicate surgery and may be associated with poor oncological outcomes with high local recurrence rate, despite no significant difference in complications. Utilizing adjuvant or intra-operative radiation may be beneficial.

Pathological response of colorectal peritoneal metastasis (CRPM) may affect prognosis. We investigated the relationship between oncological outcomes and pathological response to chemotherapy of CRPM following cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). We conducted a retrospective analysis of a prospectively maintained Peritoneal Surface Malignancies database between 2015 and 2020. Analysis included patients with CRPM who underwent a CRS/HIPEC procedure (n = 178). The cohort was divided into three groups according to the response ratio (ratio of tumor-positive specimens to the total number of specimens resected): Group A, complete response; Group B, high response ratio, and Group C, low response ratio. The group demographics were similar, but the overall complication rate was higher in Group C (65.2%) compared with Groups A (55%) and B (42.8%) [p = 0.03]. Survival correlated to response ratio; the estimated median disease-free survival of Group C was 9.1 months (5.97–12.23), 14.9 months (4.72–25.08) for Group B, and was not reached in Group A (p = 0.001). The estimated median overall survival in Group C was 35 months (26.69–43.31), and was not reached in Groups A and B (p = 0.001). The pathological response ratio to systemic therapy correlates with survival in patients undergoing CRS/HIPEC. This study supports the utilization of preoperative therapy for better patient selection, with a potential impact on survival.

Cytoreductive surgery and heated intraperitoneal chemotherapy (CRS/HIPEC) for colorectal cancer peritoneal metastases (CRPM) is associated with improved survival in patients with historically dismal prognosis. Nonetheless, peritoneal recurrences remain common and represent a difficult challenge in these patients' management. Repeat CRS/HIPEC is associated with even greater morbidity and its survival benefit has not yet been clearly demonstrated. We retrospectively reviewed our prospectively maintained database and aimed to assess the safety and oncological efficacy of repeat CRS/HIPEC. Two hundred thirty-two patients underwent an initial CRS/HIPEC, whereas 30 subsequently had repeat CRS/HIPEC for CRPM. Groups were similar in demographics, comorbidities, and peritoneal cancer index (PCI). No significant difference in morbidity, hospital stay, or reoperation rate was noted between initial and repeat procedures. Patients who underwent repeat CRS/HIPEC had a median overall survival of 68 months versus 51 months in patients who did not undergo repeat procedure for their peritoneal recurrence (p = 0.03). Disease-free survival (DFS) in patients after repeat and after initial procedure were similar with median of 9.6 versus 12 months, respectively (p = 0.083). Univariate analysis demonstrated that PCI, DFS, and repeat procedure displayed significant factors on outcomes in patients with peritoneal recurrences, whereas PCI > 16 and DFS remained independent predictors on multivariable analysis. Our analysis, which represents the largest series to date of repeat CRS/HIPEC for CRPM, indicates that this approach as a part of multimodal therapy is both safe and efficacious in appropriately selected patients.

Background The advent of immune checkpoint inhibition therapy has dramatically improved survival in patients with skin melanoma. Survival outcomes after resection of anorectal melanoma treated with immune checkpoint inhibition have not been reported. Objective This study aimed to compare survival outcomes following surgical resection of anorectal melanoma between patients who received immune checkpoint inhibition and patients who did not. Design This study is a retrospective analysis of data from a prospectively maintained database. Setting This study was conducted at a comprehensive cancer center. Patients Patients who underwent surgery for anorectal melanoma between 2006 and 2017 were included. They were stratified according to the use of immune checkpoint inhibition. Main outcome measures The primary outcomes measured were overall and disease-specific survival. Results Of the 47 patients included in the analysis, 29 (62%) received immune checkpoint inhibition therapy. Twenty-two (76%) of the 29 patients received immune checkpoint inhibition after detection of metastasis or disease progression rather than in the neoadjuvant or adjuvant setting. Overall survival did not differ significantly between patients who received immune checkpoint inhibition therapy and patients who did not (median, 52 and 20 months; 5-year rate, 41% vs 35%; p = 0.25). Disease-specific survival also did not differ significantly. Our analysis did not identify any clinical or pathological features associated with response to immune checkpoint inhibition therapy or with survival. Limitations This study was limited by its relatively small sample and retrospective design and by the heterogeneous treatment regimen in the immune checkpoint inhibition group. Conclusions Immune checkpoint inhibition therapy by itself does not appear to improve survival in patients who undergo resection or excision of anorectal melanoma. Combinations of immune checkpoint inhibition with other therapeutic modalities warrant further investigation. See Video Abstract at http://links.lww.com/DCR/B499. MELANOMA DE LA MUCOSA ANORRECTAL EN LA ERA DE LOS INHIBIDORES DEL PUNTO DE CONTROL INMUNOLOGICO: ?DEBEMOS DE CAMBIAR NUESTRO PARADIGMA DEL MANEJO QUIRURGICO: El advenimiento de la terapia de los inhibidores del punto de control inmunologico, han mejorado dramaticamente la supervivencia en pacientes con melanoma de piel. No se han informado los resultados de supervivencia despues de la reseccion del melanoma anorrectal, tratado con inhibidores del punto de control inmunologico.Comparar los resultados de supervivencia despues de la reseccion quirurgica de melanoma anorrectal entre pacientes que recibieron y no recibieron inhibidores del punto de control inmunologico.Analisis retrospectivo de una base de datos mantenida prospectivamente.Centro oncologico integral.Pacientes que se sometieron a cirugia por melanoma anorrectal entre 2006 y 2017. Los pacientes fueron estratificados segun el uso de inhibidores del punto de control inmunologico.Supervivencia global y especifica de la enfermedad.De los 47 pacientes incluidos en el analisis, 29 (62%) recibieron terapia de inhibidores del punto de control inmunologico. Veintidos (76%) de los 29 pacientes recibieron inhibidores del punto de control inmunologico despues de la deteccion de metastasis o progresion de la enfermedad, en vez de administracion adyuvante o neoadyuvante. La supervivencia global no vario significativamente entre los pacientes que recibieron o no recibieron terapia de inhibidores del punto de control inmunologico (mediana, 52 y 20 meses, respectivamente; tasa a 5 anos, 41% frente a 35%, respectivamente; p = 0,25). La supervivencia especifica de la enfermedad tampoco vario significativamente. Nuestro analisis no identifico ninguna caracteristica clinica o patologica, asociada con la respuesta a la terapia de inhibidores del punto de control inmunologico o con la supervivencia.Muestra relativamente pequena y diseno retrospectivo. Regimen de tratamiento heterogeneo en el grupo de inhibidores del punto de control inmunologico.La terapia por si sola, de inhibidores del punto de control inmunologico, no parece mejorar la supervivencia en pacientes que se someten a reseccion o escision de melanoma anorrectal. Las combinaciones de inhibidores del punto de control inmunologico con otras modalidades terapeuticas, merecen una mayor investigacion. Consulte Video Resumen en http://links.lww.com/DCR/B499. (Traduccion-Dr. Fidel Ruiz Healy).

Tissue survival responses to ionizing radiation are nonlinear with dose, rather yielding tissue-specific descending curves that impede straightforward analysis of biologic effects. Apoptotic cell death often occurs at low doses, while at clinically relevant intermediate doses, double-strand break misrepair yields mitotic death that determines outcome. As researchers frequently use a single low dose for experimentation, such strategies may inaccurately depict inherent tissue responses. Cutting edge radiobiology has adopted full dose survival profiling and devised mathematical algorithms to fit curves to observed data to generate highly reproducible numerical data that accurately define clinically relevant inherent radiosensitivities. Here, we established a protocol for irradiating organoids that delivers radiation profiles simulating the organ of origin. This technique yielded highly similar dose–survival curves of small and large intestinal crypts in vivo and their cognate organoids analyzed by the single-hit multi-target (SHMT) algorithm, outcomes reflecting the inherent radiation profile of their respective Lgr5+ stem cell populations. As this technological advance is quantitative, it will be useful for accurate evaluation of intestinal (patho)physiology and drug screening. Significance: These findings establish standards for irradiating organoids that deliver radiation profiles that phenocopy the organ of origin. See related commentary by Muschel et al., p. 927

Small-bowel obstruction (SBO) after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is a common complication associated with re-admission that may alter patients' outcomes. Our aim was to characterize and investigate the impact of bowel obstruction on patients' prognosis.This was a retrospective analysis of patients with SBO after CRS/HIPEC (n = 392). We analyzed patients' demographics, operative and perioperative details, SBO re-admission data, and long-term oncological outcomes.Out of 366 patients, 73 (19.9%) were re-admitted with SBO. The cause was adhesive in 42 (57.5%) and malignant (MBO) in 31 (42.5%). The median time to obstruction was 7.7 months (range, 0.5-60.9). Surgical intervention was required in 21/73 (28.7%) patients. Obstruction eventually resolved (spontaneous or by surgical intervention) in 56/73 (76.7%) patients. Univariant analysis identified intraperitoneal chemotherapy agents: mitomycin C (MMC) (HR 3.2, p = 0.003), cisplatin (HR 0.3, p = 0.03), and doxorubicin (HR 0.25, p = 0.018) to be associated with obstruction-free survival (OFS). Postoperative complications such as surgical site infection (SSI), (HR 2.2, p = 0.001) and collection (HR 2.07, p = 0.015) were associated with worse OFS. Multivariate analysis maintained MMC (HR 2.9, p = 0.006), SSI (HR 1.19, p = 0.001), and intra-abdominal collection (HR 2.19, p = 0.009) as independently associated with OFS. While disease-free survival was similar between the groups, overall survival (OS) was better in the non-obstruction group compared with the obstruction group (p = 0.03).SBO after CRS/HIPEC is common and complex in management. Although conservative management was successful in most patients, surgery was required more frequently in patients with MBO. Patients with SBO demonstrate decreased survival.

Metastatic spread of malignant melanoma to the abdomen presents a therapeutic challenge. Targeted and Immune-therapies dramatically improve patients' survival, yet some patients may still benefit from surgical intervention. This study investigates the outcomes of surgical treatment of abdominal metastatic melanoma in the era of modern therapy.This is a retrospective study of all patients who underwent surgical resection for abdominal metastatic melanoma between the years 2009-2021 (n = 80). We examined the clinical, operative, perioperative, and oncological outcomes of these patients.The cohort included a therapeutic group (T, n = 43) and palliative group (P, n = 37). The rate of overall post-operative complications was lower in the T group (n = 3, 9.3%) compared to the P group (n = 10, 27.1%) (p = 0.04), but no difference in major complications rate (p = 0.41). The median follow-up was 13.4 months (range, 0.5-107), with an estimated 2- and 5-years survival of 66.5% and 45.3% respectively. The estimated 2- and 5-years survival of the T group was 76.61% and 69.65%, and 49.01% and 28.01% in the P group (p = 0.005). Univariate analysis identified Therapeutic resection (HR 3.2, p = 0.008), isolated lesions (HR 1.47, p = 0.033) and major complication score (HR 1.8, p=0.001) to be correlated with survival. On multivariate analysis, Therapeutic resection (HR 2.53, p = 0.042) and major complication score (HR 1.62, p = 0.004) remained significant independent factors correlated with survival. In patients who progressed on treatment, and their progression was treated with surgical resection 46.1% where able to be maintained on the same preoperative treatment strategy.We have demonstrated that abdominal metastesectomy is a safe and oncologically efficacious therapy in selected patients. Especially in the era of modern therapeutics, patients with isolated disease site, limited resectable progression on therapy, or patients with symptomatic metastases should be considered for surgical resection.

Recent data establish a logarithmic expansion of leucine rich repeat containing G protein coupled receptor 5-positive (Lgr5+) colonic epithelial stem cells (CESCs) in human colorectal cancer (CRC). Complementary studies using the murine 2-stage azoxymethane-dextran sulfate sodium (AOM-DSS) colitis-associated tumor model indicate early acquisition of Wnt pathway mutations drives CESC expansion during adenoma progression. Here, subdivision of the AOM-DSS model into in vivo and in vitro stages revealed DSS induced physical separation of CESCs from stem cell niche cells and basal lamina, a source of Wnt signals, within hours, disabling the stem cell program. While AOM delivery in vivo under non-adenoma-forming conditions yielded phenotypically normal mucosa and organoids derived thereof, niche injury ex vivo by progressive DSS dose escalation facilitated outgrowth of Wnt-independent dysplastic organoids. These organoids contained 10-fold increased Lgr5+ CESCs with gain-of-function Wnt mutations orthologous to human CRC driver mutations. We posit CRC originates by niche injury-induced outgrowth of normally suppressed mutated stem cells, consistent with models of adaptive oncogenesis.

IntroductionDespite optimal patient selection and surgical effort, recurrence is seen in over 70% of patients undergoing cytoreductive surgery (CRS) for peritoneal metastases (PM). Apart from the Peritoneal Cancer Index (PCI), completeness of cytoreduction and tumour grade, there are other factors like disease distribution in the peritoneal cavity, pathological response to systemic chemotherapy (SC), lymph node metastases and morphology of PM which may have prognostic value. One reason for the underutilisation of these factors is that they are known only after surgery. Identifying clinical predictors, specifically radiological predictors, could lead to better utilisation of these factors in clinical decision making and the extent of peritoneal resection performed for different tumours. This study aims to study these factors, their impact on survival and identify clinical and radiological predictors.Methods and analysisThere is no therapeutic intervention in the study. All patients with biopsy-proven PM from colorectal, appendiceal, gastric and ovarian cancer and peritoneal mesothelioma undergoing CRS will be included. The demographic, clinical, radiological, surgical and pathological details will be collected according to a prespecified format that includes details regarding distribution of disease, morphology of PM, regional node involvement and pathological response to SC. In addition to the absolute value of PCI, the structures bearing the largest tumour nodules and a description of the morphology in each region will be recorded. A correlation between the surgical, radiological and pathological findings will be performed and the impact of these potential prognostic factors on progression-free and overall survival determined. The practices pertaining to radiological and pathological reporting at different centres will be studied.Ethics and disseminationThe study protocol has been approved by the Zydus Hospital ethics committee (27 July, 2020) and Lyon-Sud ethics committee (A15-128).Trial registration numberCTRI/2020/09/027709; Pre-results.

Background Peritoneal cancer index (PCI) has been used reliably to prognosticate patients with peritoneal metastasis, however, it fails to describe the patterns of peritoneal spread and to correlate these patterns to survival outcomes. We aim to define the scattered peritoneal spread (SPS) as a pattern associated with worse survival in colorectal peritoneal metastasis. Methods A retrospective analysis of metastatic colorectal cancer patients from a prospectively maintained database of peritoneal surface malignances (n = 280) between 2015 and 2020. SPS was defined by the presence of at least two distant and non-contiguous PCI regions. We compared patients with SPS (n = 73) and clustered peritoneal spread (CPS) (n = 88) for demographics, perioperative and survival outcomes. Results No difference in demographics or post-operative course was noted between the groups. The median follow-up was 15.4 months (0.4–70.8 months). Worse disease-free survival (DFS) in the SPS group with an estimated median of 8.2 months compared to 22.5 months in the CPS spread group, (p = 0.001). The estimated median overall survival (OS) for SPS group was 35.7 months whereas in the CPS group the median was not reached (p = 0.025). The same effect of SPS was preserved even after stratification of PCI. Conclusions We defined and described the association of the peritoneal spread pattern to survival outcomes. SPS patients exhibit worse DFS and OS independent of the PCI level. Integration of malignant spread pattern into prognostication models along with PCI may aid in predicting oncological outcomes.

IntroductionDespite optimal patient selection and surgical effort, recurrence is seen in over 70% of patients undergoing cytoreductive surgery(CRS) for peritoneal metastases (PM). Apart from the peritoneal cancer index(PCI), completeness of cytoreduction and tumor grade, there are other factors like disease distribution in the peritoneal cavity, pathological response to systemic chemotherapy(SC), lymph node metastases and morphology of PM which may have prognostic value. One reason for the underutilization of these factors is that they are known only after surgery. Identifying clinical predictors, specifically radiological predictors, could lead to better utilization of these factors in clinical decision making and the extent of peritoneal resection performed for different tumors. This study aims to study these factors, their impact on survival and identify clinical and radiological predictors. Methods and analysisThere is no therapeutic intervention in the study. All patients with biopsy proven PM from colorectal, appendiceal, gastric and ovarian cancer and peritoneal mesothelioma undergoing CRS will be included. The demographic, clinical, radiological, surgical and pathological details will be collected according to a pre-specified format that includes details regarding distribution of disease, morphology of PM, regional node involvement and pathological response to SC. In addition to the absolute value of PCI, the structures bearing the largest tumor nodules and a description of the morphology in each region will be recorded. A correlation between the surgical, radiological and pathological findings will be performed and the impact of these potential prognostic factors on progression-free and overall survival determined. The practices pertaining to radiological and pathological reporting at different centers will be studied. Ethics and disseminationThe study protocol has been approved by the Zydus Hospital ethics committee (27th July, 2020) and Lyon-sud ethics committee (A15-128). It is registered with the clinical trials registry of India (CTRI/2020/09/027709).The results will be published in peer-reviewed scientific journals.Strength and limitationsA prospective correlation between the radiological, surgical and pathological findings in patients undergoing CRS will be performed which has not been done before.Being prospective in nature it will also enable us to evaluate the impact of the current treatment practices on the clinical end-pointsThere is fixed protocol for radiological and pathological evaluation for which there are no specific guidelinesThe data collection format will capture all the relevant data but this may affect compliance.Despite the large sample size planned for each primary site, the heterogeneity of treatment protocols may be a limiting factor while evaluating the impact on survival.

Background Although diverting loop ileostomy (DLI) reversal is considered to be a relatively simple procedure, it is not immune from major morbidity. We aimed to compare outcomes of DLI reversal between elderly and non-elderly patients. Methods Retrospective review of all patients who underwent DLI reversal at a single tertiary medical centre between 2010 and 2020. The elderly group consisted of patients 70 or older compared to a control group of those younger than 70 years. Results During the study period, 307 patients underwent DLI reversal. Of these, 76 patients were in the elderly group (mean age 75.6) and 231 in the control group (mean age 55.3). The groups were comparable in terms of mean time interval between the creation of the ileostomy and reversal (242 versus 255 days, respectively, P = 0.5), choice between stapled and hand-sewn anastomoses (97.4% stapled anastomosis versus 93.1%, P = 0.086), median post-operative length of stay (5 days in both, P = 0.086), rates of post-operative complications (26.3% versus 26.8%, P = 0.99), severe complications (5.3% versus 6.9%, P = 0.81) and 30-day readmission rates (13.2% versus 10.8%, P = 0.58). Multivariate analysis found the time interval between the creation of the stoma and its reversal to be the only significant risk factor for major post-operative morbidity. Age was not found to be correlated with post-operative morbidity. Conclusion The outcomes of loop ileostomy reversal in elderly patients are similar to non-elderly patients. Efforts should be made to decrease the time interval between the creation of the stoma and its reversal as this is a significant risk factor for major post-operative morbidity.

Cytoreductive surgery and heated intraperitoneal chemotherapy (CRS/HIPEC) for colorectal cancer peritoneal metastases (CRPM) is associated with improved survival in patients with historically dismal prognosis. Nonetheless, peritoneal recurrences remain common and represent a difficult challenge in these patients' management. Repeat CRS/HIPEC is associated with even greater morbidity and its survival benefit has not yet been clearly demonstrated.We retrospectively reviewed our prospectively maintained database and aimed to assess the safety and oncological efficacy of repeat CRS/HIPEC.Two hundred thirty-two patients underwent an initial CRS/HIPEC, whereas 30 subsequently had repeat CRS/HIPEC for CRPM. Groups were similar in demographics, comorbidities, and peritoneal cancer index (PCI). No significant difference in morbidity, hospital stay, or reoperation rate was noted between initial and repeat procedures. Patients who underwent repeat CRS/HIPEC had a median overall survival of 68 months versus 51 months in patients who did not undergo repeat procedure for their peritoneal recurrence (p = 0.03). Disease-free survival (DFS) in patients after repeat and after initial procedure were similar with median of 9.6 versus 12 months, respectively (p = 0.083). Univariate analysis demonstrated that PCI, DFS, and repeat procedure displayed significant factors on outcomes in patients with peritoneal recurrences, whereas PCI16 and DFS remained independent predictors on multivariable analysis.Our analysis, which represents the largest series to date of repeat CRS/HIPEC for CRPM, indicates that this approach as a part of multimodal therapy is both safe and efficacious in appropriately selected patients.

Synchronous peritoneal and liver metastasis in colorectal cancer is a relative contraindication for curative surgery. We aimed to evaluate the safety and oncological outcomes of combined treatment of peritoneal and liver metastasis. We conducted a retrospective analysis of metastatic colorectal cancer patients from two prospective databases: peritoneal surface malignancy (n = 536) and hepatobiliary (n = 286). We compared 60 patients treated with cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC) and hepatectomy; 80 patients treated with cytoreduction and HIPEC only; and 63 patients treated with hepatectomy alone. No differences in demographics were observed between the groups. Median hospital and intensive care unit (ICU) stay was shorter in group C (7 and 1 days, respectively) versus groups A and B (13 and 1 days, and 12 and 1 days, respectively; p

BACKGROUND. The aim of this study was to evaluate outcomes in patients with peritoneal metastasis of colorectal cancer (pmCRC) who underwent cytoreductive surgery and intraperitoneal chemotherapy (CRS/IPC) in relation to the location of the primary tumor. Regional therapy including cytoreductive surgery and intraperitoneal chemotherapy has been associated with improved survival in patients with pmCRC. Location of the primary tumor has been shown to be prognostic in patients with metastasis. METHODS. A retrospective review was performed for all patients who underwent complete cytoreduction and intraperitoneal chemotherapy from 2010 to 2017, examining patient and tumor characteristics, overall and recurrence-free survival, recurrence patterns, and tumor mutational profiles. RESULTS. Ninety-three patients were included in the study: 49 (53%) with a right-sided and 44 (47%) with a left-sided primary tumor. Patients with a right-sided tumor had significantly shorter recurrence-free survival (median, 6.3 months [95% CI, 4.7–8.1] vs 12.3 months [95% CI, 3.6–21.7]; P = 0.02) and overall survival (median, 36.6 months [95% CI, 26.4–46.9] vs 83.3 months [95% CI 44.2–122.4]; P = 0.03). BRAF and KRAS mutations were more frequent in right-sided tumors, and APC and TP53 mutations were more frequent in left-sided tumors, which were more chromosomally instable. BRAF mutations were associated with early recurrence. CONCLUSIONS. Tumor sidedness is a predictor of oncological outcomes after CRS/IPC. Tumor sidedness and molecular characteristics should be considered when counseling patients regarding expected outcomes and when selecting or stratifying pmCRC patients for clinical trials of regional therapy.

Stem cells of the small and large intestine are marked by expression of the Wnt target gene LGR5, a leucine-rich-repeat-containing G protein-coupled receptor. Previous studies reported increased expression of LGR5 in human colorectal cancer (CRC) compared to normal tissue either by immunohistochemistry or in situ hybridization (ISH). However, as these studies were semi-quantitative they did not provide a numerical estimate of the magnitude of this effect. While we confirm that LGR5+ cells are exclusively located at the base of normal human small and large intestinal crypts, representing approximately 6% of total crypt cells, we show this cell population is 10-fold expanded in all grades of CRC, representing as much as 70% of the cells of tumor crypt-like structures. This expansion of the LGR5 compartment coincides with maintenance of crypt-like glandular structure (adenomas, and well and moderately differentiated adenocarcinomas), and is reduced in poorly differentiated CRC, where crypt-like glandular architecture is lost, accompanied by reduced epithelial terminal differentiation. Altogether these results indicate that LGR5+ cell expansion is a hallmark of CRC tumorigenesis occurring during progression to adenoma, supporting CRC as a stem cell disease with implications for CRC therapy.

Recent evidence suggests that mammary cells expressing R-spondin receptor and Wnt pathway regulator Lgr5, regarded as a stem cell marker in multiple tissues, might represent mammary stem cells (MaSCs). Whether L gr5 marks a multipotent subpopulation of Lin-CD24low/medCD49fhigh MaSCs remains controversial. To some extent the differing results reflect different assays used to assess properties of stemness, including lineage tracing in vivo, mammosphere culture, and mammary fat pad transplantation assays. To address this issue directly, we isolated Lgr5+ cells from mammary glands of Lgr5-lacZ mice and established organoids based on principles adapted from studies of Wnt-driven Lgr5+ cell populations in other organs. Mammary organoids were grown from single Lgr5+ mammary cells in Matrigel, the substratum of choice for intestinal organoids, and in a growth factor cocktail containing EGF, Wnt3a and R-spondin, designed to optimally activate the endogenous Wnt signaling program of stem cells. Colonies derived from single Lgr5+ cells manifest at least four distinct cell populations: Lgr5+ and Lgr5− basal cells and c-Kit+ and c-Kit− luminal cells that spontaneously organize into a ductal structure with basal cells around the periphery and luminal cells lining an interior cavity, reminiscent of normal mammary duct structure. Lgr5+ cell-derived organoids were sustainable during prolonged passaging. In contrast, although Lgr5− cells expand into primary colonies, colony-forming efficiency immediately dissipated upon passaging. Furthermore, reproductive hormones induce epithelial cell proliferation resulting in marked increases in lumen diameter accompanied by squamous transdifferentiation. We propose this estrogen-responsive, self-organizing duct-like structure derived from single murine Lgr5+ mammary cells represents a “mini-breast” organoid.

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.

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 individual patients. We established a biorepository of 32 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 theirex vivoresponses to clinically relevant chemotherapy and radiation treatment correlate well with responses noted in individual patients’ tumors. Upon engraftment into murine rectal mucosa, human RC tumoroids gave rise to invasive rectal cancer followed by metastasis to lung and liver. Importantly, engrafted tumors closely reflected 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,in vitroplatform coupled with endoluminal propagation in animals.

Stem cells of the small and large intestine are marked by expression of the Wnt target gene LGR5, a leucine-rich-repeat-containing G protein-coupled receptor. Previous studies reported increased expression of LGR5 in human colorectal cancer (CRC) compared to normal tissue either by immunohistochemistry or in situ hybridization (ISH). However, as these studies were semi-quantitative they did not provide a numerical estimate of the magnitude of this effect. While we confirm that LGR5+ cells are exclusively located at the base of normal human small and large intestinal crypts, representing approximately 6% of total crypt cells, we show this cell population is 10-fold expanded in all grades of CRC, representing as much as 70% of the cells of tumor crypt-like structures. This expansion of the LGR5 compartment coincides with maintenance of crypt-like glandular structure (adenomas, and well and moderately differentiated adenocarcinomas), and is reduced in poorly differentiated CRC, where crypt-like glandular architecture is lost, accompanied by reduced epithelial terminal differentiation. Altogether these results indicate that LGR5+ cell expansion is a hallmark of CRC tumorigenesis occurring during progression to adenoma, supporting CRC as a stem cell disease with implications for CRC therapy.