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Background: The primary treatment for non-metastatic rectal cancer is curative resection. However, sphincter-preserving surgery may lead to complications. This study aims to develop a predictive model for stoma non-closure in rectal cancer patients who underwent curative-intent low anterior resection., Methods: Consecutive patients diagnosed with non-metastatic rectal cancer between January 2005 and December 2017, who underwent low anterior resection, were retrospectively included in the Chang Gung Memorial Foundation Institutional Review Board. A comprehensive evaluation and analysis of potential risk factors linked to stoma non-closure were performed., Results: Out of 956 patients with temporary stomas, 10.3% (n = 103) experienced non-closure primarily due to cancer recurrence and anastomosis-related issues. Through multivariate analysis, several preoperative risk factors significantly associated with stoma non-closure were identified, including advanced age, anastomotic leakage, positive nodal status, high preoperative CEA levels, lower rectal cancer presence, margin involvement, and an eGFR below 30 mL/min/1.73m2. A risk assessment model achieved an AUC of 0.724, with a cutoff of 2.5, 84.5% sensitivity, and 51.4% specificity. Importantly, the non-closure rate could rise to 16.6% when more than two risk factors were present, starkly contrasting the 3.7% non-closure rate observed in cases with a risk score of 2 or below (p < 0.001)., Conclusion: Prognostic risk factors associated with the non-closure of a temporary stoma include advanced age, symptomatic anastomotic leakage, nodal status, high CEA levels, margin involvement, and an eGFR below 30 mL/min/1.73m2. Hence, it is crucial for surgeons to evaluate these factors and provide patients with a comprehensive prognosis before undergoing surgical intervention., (© 2024. The Author(s).)

Purpose: Low anterior resection syndrome (LARS) has had many impacts on the lives of patients and substantial differences in emotional and social functions. The aim of this study was to investigate the correlation analysis of different personality traits in rectal cancer patients with LARS after undergoing curative surgery., Methods: This study was designed as a prospective cohort study. The inclusion criteria included (1) participants diagnosed with rectal cancer who underwent surgical resection of malignant tumors and (2) ECOG 0-1. The primary outcome was the correlation between different personality traits and low anterior resection syndrome in rectal cancer patients after radical surgery. Low anterior resection syndrome incidence rates were estimated by questionnaires and personality groups by the Type A and Type D Scale-14 Personality Inventory., Results: For all 161 participants in this study, the presence of a tumor at the lower anal verge and the receipt of neoadjuvant CCRT had a statistically significant positive correlation with the LARS score at 1 month, 6 months, and 1 year (Pearson correlation coefficient = -0.283, -0.374, and - 0.205, respectively), with a p value of less than 0.05. Personalities with Type A, Type D, and Type D-SI scores had a statistically significant positive correlation with LARS score at 1 month (Pearson correlation coefficient = 0.172, 0.162, and 0,164, p value = 0.03, 0.04, and 0.04)., Conclusion: Type A and Type D personalities are highly linked to LARS. Personalized support approaches can ultimately assist rectal cancer patients in overcoming difficulties after surgery and recovery and enhance their functional outcomes., (© 2024 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Background: Evidence regarding postoperative CEA for predicting long-term outcomes of colorectal cancer remains controversial, especially in patients with normal postoperative CEA., Objective: To investigate the risk difference among different postoperative CEA trajectories in patients with normal postoperative CEA after curative colorectal cancer resection., Design: This cohort study was conducted at a comprehensive cancer center and included data retrieved from a prospectively collected database between January 2006 and December 2018., Settings: Retrospective cohort study., Patients: Patients with colorectal cancer who underwent surgery for primary stage I to III colorectal adenocarcinoma were included and those with postoperative CEA >5 ng/mL were excluded., Interventions: Standard curative radical resection was performed., Main Outcome Measures: Ten-year overall survival and disease-free survival were analyzed., Results: The study population (n = 8156) was categorized into 6 trajectories: persistent-ultralow (n = 2351), persistent-low (n = 2474), gradually decrease (n = 401), persistent-medium (n = 1727), slightly increase (n = 909), and around-upper-limit (n = 394). The median follow-up time was 7.8 years, and the median time frame in which CEA was measured to determine trajectory was 2.6 years. The persistent-ultralow group had the highest 10-year overall survival (85.1%) and disease-free survival (82.7%). The around-upper-limit group had the lowest 10-year overall survival (55.5%) and disease-free survival (53.4%). The adjusted HR trend was comparable to the crude HR of the persistent-ultralow group. Consequently, the higher initial serum CEA groups had higher HRs of overall survival and disease-free survival. The adjusted HR of overall survival was 2.96 (95% CI, 2.39-3.66) and of disease-free survival was 2.66 (95% CI, 2.18-3.69) for the around-upper-limit groups., Limitations: Retrospective design., Conclusions: The postoperative serum CEA trajectory is an independent factor associated with long-term outcomes. Although CEA levels were all within normal range, higher levels of postoperative serum CEA trajectory correlated with worse long-term oncological outcomes. See Video Abstract., Trayectorias De Marcadores Tumorales Y Anlisis De Supervivencia En Pacientes Con Rangos Normales De Antgeno Carcinoembrionario Posterior a Reseccin De Cncer Colorrectal: ANTECEDENTES:La evidencia sobre el CEA post operatorio para la predicción de los resultados a largo plazo del cáncer colorrectal sigue siendo controversial, especialmente en pacientes con CEA post quirúrgico normal.OBJETIVO:Investigar la diferencia de riesgo entre diferentes trayectorias postoperatorias del CEA en pacientes con CEA post quirúrgico normal tras la resección curativa del cáncer colorrectal.DISEÑO:Este estudio de cohorte se realizó en un centro oncológico integral e incluyó datos recuperados de una base de datos recopilada prospectivamente entre enero de 2006 y diciembre de 2018.AJUSTES:Estudio de cohorte retrospectivo.PACIENTES:Se incluyeron pacientes con el diagnostico de CCR que fueron sometidos a cirugía por adenocarcinoma colorrectal primario en estadio I-III. Se excluyeron pacientes con CEA postoperatorio >5 ng/mL.INTERVENCIONES:Se realizó una resección radical curativa estandarizada.PRINCIPALES MEDIDAS DE RESULTADO:Se analizaron la supervivencia general a diez años y la supervivencia libre de enfermedad.RESULTADOS:La población de estudio (n = 8156) fue clasificada en seis trayectorias, que incluyeron ultrabajo persistente (n = 2351), bajo persistente (n = 2474), disminución gradual (n = 401), medio persistente (n = 1727), aumento leve (n = 909) y alrededor del límite superior (n = 394). La mediana del tiempo de seguimiento fue de 7,8 años y la mediana del período de tiempo en el que el CEA fue medido para determinar la trayectoria fue de 2,6 años. El grupo ultrabajo persistente tuvo la mayor supervivencia general a 10 años (85,1 %) y supervivencia libre de enfermedad (82,7 %). El grupo alrededor del límite superior tuvo la supervivencia general a 10 años más baja (55,5 %) y la supervivencia libre de enfermedad (53,4 %). La tendencia del índice de riesgo ajustado fue comparable al índice de riesgo bruto del grupo ultrabajo persistente. En consecuencia, los grupos con CEA sérico iniciales más altos tenían índices de riesgos más altos de supervivencia general y supervivencia libre de enfermedad. Los índices de riesgos ajustados de supervivencia general/supervivencia libre de enfermedad fueron 2,96/2,66 (intervalo de confianza del 95 %: 2,39-3,66/2,18-3,69) para los grupos cercanos al límite superior.LIMITACIONES:El estudio estuvo limitado por su diseño retrospectivo.CONCLUSIONES:La trayectoria del CEA sérico postoperatorio es un factor independiente asociado con resultados a largo plazo. Aunque los niveles de CEA se encontraban todos dentro del rango normal, los niveles más altos de trayectoria del CEA en suero posoperatorio se correlacionaron con peores resultados oncológicos a largo plazo. (Traducción-Dr Osvaldo Gauto )., (Copyright © The ASCRS 2023.)

Background: To summarize the chemo-radio effect of metformin in rectal cancers with neoadjuvant chemoradiotherapy on pathological response, tumor regression grade (TRG), and T/N downstaging., Methods: PubMed, MEDLINE, Embase, and Cochrane Database of collected reviews were searched up to June 30, 2022. This study conducted systematic review and meta-analysis based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) sheet. Odds ratios (ORs) and confidence intervals (CIs) which calculated by random-effects models were displayed in forest plots. Newcastle-Ottawa scale was used to assess the risk of bias of the observational cohort studies., Results: This systematic review and meta-analysis comprised eight cohorts out of seven studies, with 2294 patients in total. We performed two-way comparison for metformin in diabetic patients vs (1) non-metformin drugs in diabetic patients and (2) nondiabetic patients. In diabetes patient studies, the metformin group had a significantly increased pathological response on TRG (OR: 3.28, CI: 2.01-5.35, I 2  = 0%, p < 0.001) and T downstaging (OR: 2.14, CI: 1.24-3.67, I 2  = 14%, p = 0.006) in comparison with a non-metformin group. When compared with nondiabetic patients, the pathological response on TRG (OR: 2.67, CI: 1.65-4.32, I 2  = 43%, p < 0.001) and T downstaging (OR: 1.96, CI: 1.04-3.71, I 2  = 66%, p = 0.04) were also higher in metformin group. The limitation was that no randomized controlled trials were available based on current literature review. Small sample sizes for diabetic metformin or non-metformin users in rectal cancer patients reduced the power of the study., Conclusions: For patients with rectal cancer and treated with neoadjuvant chemoradiotherapy, metformin administration in diabetic patients increased the pathological response on tumor-regression grade and T downstaging. Further well-designed, high-quality randomized controlled trials are required to reveal the actual effect of metformin., (© 2023. The Author(s).)

Purpose: The optimal timing of stoma closure during or after adjuvant chemotherapy for rectal cancer patients undergoing sphincter-preserving surgery remains unknown. This study aimed to investigate the influence of clinical and oncological outcomes depending on the timing of stoma closure., Methods: Between January 2006 and December 2015, we enrolled 244 consecutive rectal cancer patients who underwent curative-intent sphincter-preserving surgery with diverting transverse colostomy and adjuvant chemotherapy. Patients with stoma closure during (During group) adjuvant chemotherapy were compared to those who had stoma closure after adjuvant chemotherapy (After group)., Results: Parastomal hernia occurred more frequently in the after group than in the during group. (10% vs. 2.9%, p = 0.028). Overall, no significant difference was observed in overall survival (OS) or disease-free survival (DFS) between the two groups (p = 0.911 for OS, p = 0.505 for DFS). However, an inferior OS occurred if reopen surgery was performed within 30 days of stoma closure in the during group, as compared with the after group (p = 0.004). In addition, a marginally poor DFS was observed in the group of patients who received further operations due to 30-day stoma closure complications compared to the other patients (p = 0.07)., Conclusions: For rectal cancer patients who underwent sphincter-preserving surgery, attention should be given to avoid 30-day major complications after stoma reversal because patients who require reoperation during adjuvant chemotherapy may have poor long-term survival., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Whether to ligate the inferior mesenteric artery at its root during anterior resection for sigmoid colon or rectal cancer is still under debate. This study compared the surgical outcomes, postoperative recovery, and anastomotic leakage between high and low ligation of the inferior mesenteric artery through a subgroup analysis., Methods: This was a retrospective analysis of prospectively collected data. All patients who underwent colorectal resection for rectosigmoid cancer between December 2016 and December 2019 were enrolled. According to the surgical ligation level of the inferior mesenteric artery, the patients were categorized into either the high or low ligation group. The investigated population was matched using the propensity score method., Results: Overall, 894 patients with sigmoid or rectal cancer underwent elective anterior resection with high (577 patients) or low (317 patients) ligation of the inferior mesenteric artery. After the propensity score matching, 245 patients in each group were compared. High ligation of the inferior mesenteric artery was associated with higher incidence of anastomotic leakage (14.9% vs. 5.6%, P = 0.041) for mid- to low-rectum tumors and a higher incidence of complications (8.6% vs. 3.3%, P = 0.013) of grades 1-2 according to the Clavien-Dindo classification system., Conclusion: Compared with high ligation, low ligation of the inferior mesenteric artery resulted in lower likelihood of morbidity and mortality in rectal and sigmoid cancers. Moreover, low ligation was less likely to result in anastomosis leakage in mid- to low-rectal cancers., (© 2023. The Author(s).)

Background: Although a temporary stoma can mitigate the severity of anastomotic leakage, some rectal cancer patients retain a permanent stoma after sphincter-preserving surgery. Therefore, this study aimed to identify independent preoperative risk factors for permanent stoma and establish a prediction model for mid-and low-rectal cancer patients who underwent sphincter-preserving surgery and temporary stoma., Methods: We retrospectively reviewed consecutive patients with non-metastatic rectal cancer between 2000 and 2015. The risk factors for permanent stomas were collected and analyzed., Results: A total of 1020 rectal cancer patients with temporary stoma were included. The overall rate of permanent stoma was 17.5% (n = 179). Cancer progression and anastomotic complications are major causes of permanent stomas. Multivariate analysis showed that preoperative risk factors such as advanced age, male sex, preoperative CEA ≥ 10 ng/ml, T4 stage, N stage, low rectal tumor, and ASA ≥ III were independent preoperative risk factors after adjustment. The ROC curve of the risk factors and permanent stoma showed an AUC of 0.689, a cut-off value of 2.5, a sensitivity of 0.689, and a specificity of 0.622. The permanent stoma rates were significantly higher between risk scores ≤ 2 and > 2 (29.9% vs. 11.3%, p < 0.001)., Conclusion: Preoperative CEA ≥ 10 ng/ml, T4 stage, N stage, low rectal tumor, advanced age, ASA ≥ III, and male sex were independent preoperative prognostic factors for a permanent stoma. The risk was higher with a score greater than two. Therefore, the risk of subsequent permanent stoma should be evaluated and informed to the patient prior to the primary surgery., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: Although cigarette smoking is a well-known risk factor for anastomotic leakage during rectal surgery, the proper duration of smoking cessation that can decrease anastomotic leakage in patients undergoing sphincter-preserving surgery is unclear. This study aimed to investigate the optimal duration of smoking cessation that can reduce this complication., Methods: Between January 1, 2000, and December 31, 2012, we enrolled 1246 consecutive patients who underwent curative-intent sphincter-preserving surgery without preventive stoma at the Division of Colorectal Surgery of a tertiary referral center in Taiwan. Questionnaires were used to record their pre-surgical smoking status. The receiver operating characteristic (ROC) curve was used to determine the optimal cut-off duration of smoking cessation. Multivariate analysis was used to verify the effect of cigarette cessation on anastomotic leakage., Results: The ROC curve showed a cut-off value of 10.5 years of cessation duration. Therefore, the former-smoker group was further divided using a cessation duration of 10 years. The overall anastomotic leakage rate was 5.29%. However, the anastomotic leakage rate in current smokers (9.3%) and in those who quit for < 10 years (12.9%) was significantly higher than that in non-smokers (3.3%) and those who quit for ≥ 10 years (4.5%). On multivariate analysis, current smokers (p = 0.022), former smokers with < 10 years of smoking cessation (OR 2.725; p = 0.029), male sex (p = 0.015), and low rectal cancer (p < 0.001) were all independently related to the development of anastomotic leakage., Conclusion: Smoking cessation for < 10 years remains a risk factor for anastomotic leakage in patients with mid-to-low rectal cancer undergoing sphincter-preserving surgery., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Radical resection is associated with good prognosis among patients with cT1/T2Nx rectal cancer. However, still some of the patients experienced cancer recurrence following radical resection. This study tried to identify the postoperative risk factors of local recurrence and distant metastasis separately., Methods: This retrospective, single-center study comprised of 279 consecutive patients from Linkou branch of Chang Gung Memorial Hospital in 2005-2016 with rectal adenocarcinoma, pT1/T2N0M0 at distance from anal verge ≤ 8cm, who received curative radical resection., Results: The study included 279 patients with pT1/pT2N0 mid-low rectal cancer with median follow-up of 73.5 months. Nineteen (6.8%) patients had disease recurrence in total. Nine (3.2%) of them had local recurrence, and fourteen (5.0%) of them had distant metastasis. Distal resection margin < 0.9 (cm) (hazard ratio = 4.9, p = 0.050) was the risk factor of local recurrence. Preoperative carcinoembryonic antigen (CEA) ≥ 5 ng/mL (hazard ratio = 9.3, p = 0.0003), lymph node yield (LNY) < 14 (hazard ratio = 5.0, p = 0.006), and distal resection margin < 1.4cm (hazard ratio = 4.0, p = 0.035) were the risk factors of distant metastasis., Conclusion: For patients with pT1/pT2N0 mid-low rectal cancer, current multidisciplinary treatment brings acceptable survival outcome. Insufficient distal resection margin attracted the awareness of risk factors for local recurrence and distant metastasis as a foundation for future research.

Background: Local excision (LE) is a feasible treatment approach for rectal cancers in stage pT1 and presents low pathological risk, whereas total mesorectal excision (TME) is a reasonable treatment for more advanced cancers. On the basis of the pathology findings, surgeons may suggest TME for patients receiving LE. This study compared the survival outcomes between LE with/without chemoradiation and TME in mid and low rectal cancer patients in stage pT1/pT2, with highly selective intermediate pathological risk., Methods: This retrospective study included 134 patients who received TME and 39 patients who underwent LE for the treatment of intermediate risk (pT1 with poor differentiation, lymphovascular invasion, perineural invasion, relatively large tumor, or small-sized pT2 tumor) rectal cancer between 1998 and 2016., Results: Overall survival (OS), disease-free survival (DFS), and cumulative recurrence rate (CRR) were similar between the LE (3-year DFS 92%) and TME (3-year DFS 91%) groups. Following subgrouping into an LE with adjuvant therapy group and a TME without adjuvant therapy group, the compared survival outcomes (OS, DFS, and CRR) were found not to be statistically different. The temporary and permanent ostomy rates were higher in the TME group than in the LE group (p < 0.001). Rates of early and late morbidity following surgery were higher in the TME group (p = 0.005), and LE had similar survival compared with TME., Conclusion: For patients who had mid and low rectal cancer in stage pT1/pT2 and intermediate pathological risk, LE with chemoradiation presents an alternative treatment option for selected patients.

Background/aims: To evaluate outcome and prognostic factors of patients with anorectal melanoma., Methodology: Twenty-two consecutive patients with anorectal melanoma received operation from 1993 through 2011 were reviewed. The definitions of stage I, II and III are local disease, locoregional lymphadenopathy and metastatic disease, respectively., Results: The patients included 8 men and 14 women, aged from 36 to 83 years (mean, 58.4 years). At the end of the follow-up period, 19 patients died of disease and only 3 patients were alive with disease. Only two patients were alive longer than 5 years after operation. For stage I and II tumors that underwent clinical curative resection (n=17), stage II (p=0.04), tumor size >3 cm (p=0.008) and invasion depth to muscle (p=0.021) all showed poorer prognosis in overall survival. Though wide local excision (WLE) were performed in the patients with earlier tumors, there was no statistical difference in overall (p=0.063) and disease-free survival (p=0.333) between WLE and radical surgery. Furthermore, patients with WLE had more chance of local recurrence than radical surgery (6/7 vs. 3/10, p=0.050). Four salvage radical operations could be performed after local recurrence in WLE group., Conclusions: WLE increases the chance of local recurrence more than radical surgery. Care should be taken to avoid microseeding during performed WLE.

Background: Local excision has become an alternative for radical resection in rectal cancer for selected patients. The purpose of this study was to assess the clinicopathologic factors determining lymph node metastasis (LNM) in patients with T1-2 rectal cancer., Methods: Between January 1995 and December 2009, a total of 943 patients with pT1 or pT2 rectal adenocarcinoma received radical resection at a single institution. Clinicopathologic factors were evaluated by univariate and multivariate analyses to identify risk factors for LNM., Results: A total of 943 patients (544 men and 399 women) treated for T1-2 rectal cancer were included in this study. LNM was found in 188 patients (19.9%). In multivariate analysis, lymphovascular invasion (LVI; P < 0.001, hazard ratio 11.472), poor differentiation (PD; P = 0.007, hazard ratio 3.218), and depth of invasion (presence of pT2; P = 0.032, hazard ratio 1.694) were significantly related to nodal involvement. The incidence for LNM lesions in the presence of LVI, PD, and pT2 was 68.8, 50.0, and 23.1%, respectively, while that for pT1 carcinomas with no LVI or PD was 7.5%., Conclusions: LVI, PD, and pT2 are independent risk factors predicting LNM in pT1-2 rectal carcinoma.

Background/aims: Predicting the lymph node metastatic or distant metastatic potential of T1 adenocarcinoma of the colon and rectum remains a major challenge. We investigated the role of the expressions of tumor matrilysin (MMP-7), VEGF-C and VEGF-A in predicting these metastatic potentials., Methodology: Single T1 adenocarcinomas were examined and pathological tumor factors were reviewed. Immunohistochemical staining of VEGF and MMP-7 was performed and the metastatic potential was defined on the basis of the presence of lymph nodes in the specimen or the identification of other distant metastasis during follow-up examinations., Results: There was little correlation between the IHC staining results of VEGF-A, VEGF-C and MMP-7 in the same specimen (kappa<0.1). After a 61-month median follow-up (2-131 months), 17 (11.8%) tumors showed metastatic potential, including 14 lymph node metastases and 3 distant metastases. The tumors showing high levels of MMP-7 expression had higher metastatic potentials than those with low expression (19.1% vs. 8.2%, respectively; p=0.057). Overexpression of MMP-7 generally indicated an inferior overall survival (p=0.09). In analysis of the traditional pathological tumor factors, only lymphovascular invasion showed significance in predicting metastatic potential (p=0.04)., Conclusions: Overexpression of MMP-7 generally indicated a higher metastatic potential and inferior overall survival. Lymphovascular invasion was a significant risk factor for lymph node metastasis.

Objective: The aim of this study was to investigate the effect of body mass index (BMI) on local recurrence of primary rectal cancer after open curative sphincter-saving resection., Background: Increasing BMI was reported to be associated with a higher likelihood of local recurrence in male patients with rectal cancer. However, it remained unclear whether BMI exerts the same effects on local recurrence of rectal cancer in the upper and lower rectum., Methods: Between January 1995 and December 2002, we investigated 1873 patients with well-documented body height and body weight who underwent curative anterior resection for primary rectal cancer in a single institution. The patients were assigned to 4 groups according to their BMI: underweight, normal, overweight, and obese., Results: The frequency of local recurrence increased with an increase in the BMI in patients with lower rectal cancer. The local recurrence rates were 2.5% (2 of 79), 6.1% (48 of 782), 9.2% (39 of 424), and 13.8% (9 of 65) in underweight, normal, overweight, and obese patients with lower rectal cancer, respectively. These results were different from those of patients with upper rectal cancer. Independent risk factors for local recurrence in the lower rectal cancer group were BMI, resection margin, histologic grade of differentiation, depth of tumor invasion, and status of lymph node metastases. In the upper rectal cancer group, the depth of tumor invasion and histologic grade of differentiation reached statistical significance., Conclusions: BMI exerted different effects on local recurrence of rectal cancer in the upper and lower rectum. Further, more aggressive adjuvant and/or neoadjuvant treatments should be considered for patients with tumor in the lower rectum and with higher BMI.

Background and Aims: Signet ring cell carcinoma of the rectum (SCCR) is a rare type of rectal carcinoma. This study examined the clinical significance of SCCR., Patients and Methods: From our medical records we retrospectively identified 61 SCCR patients and compared their clinical data and outcomes to those of 144 consecutive patients with non-SCCR mucinous rectal adenocarcinomas (NSMR) and 2,414 consecutive patients with nonmucinous rectal adenocarcinomas (NMR)., Results: . The incidence of SCCR was 1.39% of rectal cancers. Mean patient age at onset of SCCR (48.1years, range 15-80) was significantly lower than that for NSMR (57.4 years, 9-88) and NMR (62.6 years, 12-94). The proportion of late stage (TNM III+IV) tumors was significantly higher in SCCR (90%) than in NSMR (69%) and NMR (48%). There were more tumors located in the lower rectum in SCCR (46%) than in NSMR (34%) and NMR (29%). SCCR tumors were significantly larger (5.68+/-3.84 cm) than NSMR (4.27+/-1.78 cm) and NMR tumors (3.76+/-1.71 cm). A higher percentage of patients with SCCR (42.6%) received abdominoperineal resection for treatment. In tumors with TNM stage IV the rate of tumor spread via the hematogenous route was significantly lower in SCCR (18.5%) than in NSMR (43.5%) and in NMR (69%). The rate of tumor spread via seeding to the peritoneum was lower in SCCR (22.2%) than in NSMR (43.5%) but higher than in NMR (2.7%). The rate of tumor spread via the lymphatic route was higher in SCCR (44.4%) than in NSMR (26.1%) and significantly higher than in NMR (12.3%). The 1-, 2-, and 5-year overall SCCR survival rates were 73.9%, 36.3%, and 23.3% respectively, which were significantly poorer than those of NSMR and NMR. For the 28 stage III and R0 SCCR tumors the 1-, 2-, and 5-year disease-free survival rates of SCCR were 84.0%, 44.2%, and 30.3%, respectively, which are comparable with general data of stage III rectal cancer in the world., Conclusion: Diffuse infiltration of signet ring cells enhances the tendency of mucinous carcinomas of the rectum in more local extension and easier lymphatic spreading but not at peritoneal seeding. Although SCCR had the poorest prognosis, this outcome may be due to the advanced tumor stage rather than histology itself.