A postsurgical prognostic nomogram for patients with lymph node positive rectosigmoid junction adenocarcinoma.

OBJECTIVE: The definition of rectosigmoid junction (RSJ) is still in debate. The treatment and prognosis of patients with rectosigmoid junction cancer (RSJC) and positive lymph nodes (PLN-RSJCs) are mostly based on the American Joint Committee on Cancer (AJCC) staging system. Our study aims to assist clinicians in creating a more intuitive and accurate nomogram model for PLN-RSJCs for the prediction of patient overall survival (OS) after surgery. METHODS: Based on the Surveillance, Epidemiology, and End Results (SEER) database, we extracted 3384 patients with PLN-RSJCs and randomly divided them into development (n = 2344) and validation (n = 1004) cohorts at a ratio of 7:3. Using univariate and multivariate COX regression analysis, we identified independent risk factors associated with OS in PLN-RSJCs in the development cohort, which were further used to establish a nomogram model. To verify the accuracy of the model, the concordance index (C-index), receiver operating characteristic (ROC) curves, calibration curves, and an internal validation cohort have been employed. Decision curve analysis (DCA) was used to assess the clinical applicability and benefits of the generated model. Survival curves of the low- and high-risk groups were calculated using the Kaplan-Meier method together with the log-rank test. RESULTS: Age, marital, chemotherapy, AJCC stage, T and N stage of TNM system, tumor size, and regional lymph nodes were selected as independent risk factors and included in the nomogram model. The C-index of this nomogram in the development (0.751;0.737-0.765) and validation cohorts (0.750;0.764-0.736) were more significant than that of the AJCC 7th staging system (0.681; 0.665-0.697). The ROC curve with the calculated area under the curve (AUC) in the development cohort was 0.845,0.808 and 0.800 for 1-year, 3-year and 5-year OS, AUC in the validation cohort was 0.815,0.833 and 0.814 for 1-year, 3-year and 5-year, respectively. The calibration plots of both cohorts for 1-year,3-year and 5-year OS all demonstrated good agreement between actual clinical observations and predicted outcomes. In the development cohort, the DCA showed that the nomogram prediction model is more advantageous for clinical application than the AJCC 7th staging system. Kaplan-Meier curves in the low and high groups showed significant difference in patient OS. CONCLUSIONS: We established an accurate nomogram model for PLN-RSJCs, intended to support clinicians in the treatment and follow-up of patients.

Cancer of the Rectum and Rectosigmoid Junction: 20-Year Comparative Survival and Mortality Analysis by Age, Sex, Race, Stage, Grade, Cohort Entry Time-Period and Disease Duration: A Systematic Review of 266,898 Cases for Diagnosis Years 1973-2014: (SEER*Stat 8.3.4).

This article reviews a 20-year retrospective population-based study using the statistical database of SEER*Stat 8.3.4 to compare the occurrence, long-term survival and mortality indices of 266,898 patients with cancer of the rectum and rectosigmoid junction (RSJ) juxtaposed by age, sex, race, stage, grade, disease duration, in two cohort entry time-periods, 1973-1994 & 1995-2014.

Ex vivo specimen MRI and pathology confirm a rectosigmoid mesenteric waist at the junction of the mesorectum and mesocolon.

AIM: Continuity of the mesentery has recently been established and may provide an anatomical basis for optimal colorectal resectional surgery. Preliminary data from operative specimen measurements suggest there is a tapering in the mesentery of the distal sigmoid. A mesenteric waist in this area may be a risk factor for local recurrence of colorectal cancer. This study aimed to investigate the anatomical characteristics of the mesentery at the colorectal junction. METHOD: In this cross-sectional study, 20 patients were recruited. After planned colorectal resection, the surgical specimens were scanned in a MRI system and subsequently dissected and photographed as per national pathology guidelines. Mesenteric surface area and linear measurements were compared between MRI and pathology to establish the presence and location of a mesenteric waist. RESULTS: Specimen analysis confirmed that a narrowing in the mesenteric surface area was consistently apparent at the rectosigmoid junction. Above the anterior peritoneal reflection, the surface area and posterior distance of the mesentery of the upper rectum initially decreased before increasing as the mesentery of the sigmoid colon. These anatomical properties created the appearance of a mesenteric 'waist' at the rectosigmoid junction. Using the anterior reflection as a reference landmark, the rectosigmoid waist occurred at a mean height of 23.6 and 21.7 mm on MRI and pathology, respectively. CONCLUSION: A rectosigmoid waist occurs at the junction of the mesorectum and mesocolon, and is a mesenteric landmark for the rectum that is present on both radiology and pathology.

Is it possible to give a single definition of the rectosigmoid junction?

AIM: The rectosigmoid junction is the limit separating the sigmoid colon and rectum. This transition zone has different definitions. We want to highlight different landmarks of the rectosigmoid junction (RSJ), to help the clinicians to adopt a consensual definition. METHOD: We reviewed anatomical, endoscopic, physiological and surgical points of view concerning the rectosigmoid junction (RSJ). RESULTS: The rectosigmoid junction has a different definition depending on who is studying it. Nevertheless, it is a high pressure location, a place connecting different muscles organizations, neurological systems or vascular anastomosis. The clear pathophysiology of the RSJ is not yet determined with certainty, but its resection is essential for the therapeutic care of patients and also for the improvement of surgical skills. From a surgical point of view, anatomical landmarks has to be chosen: easily reproducible and identifiable. The disappearance of taenia coli (belonging to the colon) and the peritoneal reflection (recto-genital pouch), located below the upper rectum, seem the most reliable. The level of rectal section must, in any case, be below the promontory. CONCLUSION: There is not a single definition, but rather several definitions of the RSJ. Each one of them reflects one appearance of this region: embryological and anatomical evolution or clinical entity. From a surgical point of view, the criterion which seems to be the most reliable is the disappearance of taenia coli and the peritoneal reflection (recto-genital pouch).

Sigmoid take-off in rectosigmoid cancer as a landmark identifying benefit from neoadjuvant chemoradiation: A retrospective comparative cohort study.

INTRODUCTION: There is no standard treatment strategy for rectosigmoid cancer because of the diverse definitions of the proximal rectal origin. This study aimed to evaluate sigmoid take-off compared with other landmarks of the rectosigmoid junction in guiding oncological therapy and outcomes. MATERIALS AND METHODS: This retrospective, comparative cohort study included patients diagnosed with rectosigmoid carcinoma at our centre between January 2010 and December 2018. The patients were classified into the neoadjuvant treatment group and upfront surgery group. The oncological outcomes were compared between the two groups in relation to the tumor position. RESULTS: A total of 656 patients (median age 64 years) were included. After propensity score matching, the 3- and 5-year overall survival and disease-free survival in patients in both the groups were comparable. However, when only patients with rectal cancer as defined by the sigmoid take-off point were included, the disease-free survival rate in the upfront surgery group was significantly lower than that in the neoadjuvant treatment group (p = 0.03 in patients who underwent computed tomography, p = 0.03 in patients who underwent magnetic resonance imaging). The turning point of the beneficial hazard ratio of neoadjuvant therapy was compared according to the different definitions of the rectosigmoid junction and the sigmoid take-off was found to be the most effective. CONCLUSION: The sigmoid take-off point is a suitable landmark for identifying the rectosigmoid junction and is an important defining criterion for assessing the benefit of neoadjuvant therapy. The application of this definition in clinical practice and future trials is warranted.

Response to Neoadjuvant Chemoradiotherapy as a Predictor of Long-Term Survival in Patients with Locally Advanced Rectosigmoid Junction Cancer: An Analysis Based On SEER Database.

Background: Neoadjuvant chemoradiotherapy is recommended to locally advanced rectal cancer, especially for the lower and middle ones. However, the role of neoadjuvant chemoradiotherapy in rectosigmoid junction cancer remains undetermined. We investigated whether patients with a good response to neoadjuvant chemoradiotherapy will have a relatively better long-term survival compared with those with no response. Methods: Overall, 1325 patients diagnosed with locally advanced rectosigmoid junction cancer from Surveillance, Epidemiology, and End-Results (SEER) cancer registry database (2004-2014, America) were selected. All of them had received neoadjuvant chemoradiotherapy and were evaluated by Collaborative Stage Data Collection System. We performed Kaplan-Meier univariate analysis and Cox regression multivariate analysis models to estimate the potential prognostic factors of long-term survival outcomes. Response to neoadjuvant chemoradiotherapy and histological type of tumor were the two prognostic factors. Results: The 5-year OS was 78.1% in responders, and 63.4% in nonresponders. In addition the 5-year DSS was 85.1% in responders, and 72.9% in nonresponders. Conclusion: Based on SEER database in locally advanced rectosigmoid junction cancer, patients with a good response to neoadjuvant chemoradiotherapy could have a benefit of long-term survival.

Comprehension of rectosigmoid junction cancer molecular features by comparison to the rectum or sigmoid colon cancer.

Background: Colorectal cancer (CRC) is a heterogeneous cancer. Its treatment depends on its anatomical site and molecular features. Carcinomas of the rectosigmoid junction are frequent; however, specific data on these tumors are sparse, as they are frequently assigned to either the colon or rectum. This study sought to identify the molecular features of rectosigmoid junction cancer to determine whether there should be any difference between the therapeutic management of rectosigmoid junction cancer and that of sigmoid colon or rectum cancer. Methods: The data of 96 CRC patients with carcinomas in the sigmoid colon, rectosigmoid junction, and rectum were retrospectively summarized. The next-generation sequencing (NGS) data of the patients were analyzed to study the molecular characteristics of the carcinomas in different locations of the bowel. Results: In total, there was no difference in the clinicopathologic characteristics of the three groups. TP53, APC, and KRAS genes were the top 3 alteration genes in sigmoid colon, rectosigmoid junction, and rectum cancer. The rates of the KRAS, NRAS, and PIK3CA increased as the location moved distally, while the rates of APC and BRAF decreased. Almost no significant molecular differences were found among the three groups. The prevalence of the FLT3, fms-related tyrosine kinase 1 (FLT1), and phosphoenolpyruvate carboxykinase 1 (PCK1) mutation was lower in the rectosigmoid junction group than the sigmoid colon and rectum groups (P>0.05). The proportion of the transforming growth factor beta pathway was higher in the rectosigmoid junction and rectum groups than the sigmoid colon group (39.3% vs. 34.3% vs. 18.2%, respectively, P=0.121, P=0.067, P=0.682); a higher proportion of MYC pathway was also observed in the rectosigmoid junction than that in rectum and sigmoid colon (28.6% vs. 15.2% vs. 17.1%, P=0.278, P=0.202, P=0.171). Regardless of the clustering method employed, the patients were divided into two clusters, and the composition of clusters revealed no significant differences in terms of the different locations. Conclusions: Rectosigmoid junction cancer has a distinctive molecular profile compared to the molecular profiles of the adjacent bowel segment cancers.

Adult and Elderly Risk Factors of Mortality in 23,614 Emergently Admitted Patients with Rectal or Rectosigmoid Junction Malignancy.

Background: Colorectal cancer, among which are malignant neoplasms of the rectum and rectosigmoid junction, is the fourth most common cancer cause of death globally. The goal of this study was to evaluate independent predictors of in-hospital mortality in adult and elderly patients undergoing emergency admission for malignant neoplasm of the rectum and rectosigmoid junction. Methods: Demographic and clinical data were obtained from the National Inpatient Sample (NIS), 2005−2014, to evaluate adult (age 18−64 years) and elderly (65+ years) patients with malignant neoplasm of the rectum and rectosigmoid junction who underwent emergency surgery. A multivariable logistic regression model with backward elimination process was used to identify the association of predictors and in-hospital mortality. Results: A total of 10,918 non-elderly adult and 12,696 elderly patients were included in this study. Their mean (standard deviation (SD)) age was 53 (8.5) and 77.5 (8) years, respectively. The odds ratios (95% confidence interval, P-value) of some of the pertinent risk factors for mortality for operated adults were 1.04 for time to operation (95%CI: 1.02−1.07, p < 0.001), 2.83 for respiratory diseases (95%CI: 2.02−3.98), and 1.93 for cardiac disease (95%CI: 1.39−2.70), among others. Hospital length of stay was a significant risk factor as well for elderly patients­OR: 1.02 (95%CI: 1.01−1.03, p = 0.002). Conclusions: In adult patients who underwent an operation, time to operation, respiratory diseases, and cardiac disease were some of the main risk factors of mortality. In patients who did not undergo a surgical procedure, malignant neoplasm of the rectosigmoid junction, respiratory disease, and fluid and electrolyte disorders were risk factors of mortality. In this patient group, hospital length of stay was only significant for elderly patients.

Comprehensive analysis of lncRNA-associated ceRNA network reveals the novel potential of lncRNA, miRNA and mRNA biomarkers in human rectosigmoid junction cancer.

Although accumulating evidence has confirmed the potential biological functions of long non-coding RNAs (lncRNAs) as competitive endogenous RNAs (ceRNAs) in colorectal tumorigenesis and progression, few studies have focused on rectosigmoid junction cancer. In the present study, a comprehensive analysis was conducted to explore lncRNA-mediated ceRNA implications and their potential value for prognosis. lncRNA, microRNA (miR/miRNA) and mRNA expression profiles were downloaded from The Cancer Genome Atlas database. Subsequently, a lncRNA-miRNA-mRNA regulatory network was constructed to evaluate the functions of these differentially expressed genes on overall survival (OS) for rectosigmoid junction cancer. As a result, a rectosigmoid junction cancer-specific ceRNA network was successfully constructed with 7 differentially expressed (DE)lncRNAs, 16 DEmiRNAs and 71 DEmRNAs. Among the network, one DElncRNA (small nucleolar RNA host gene 20) and three mRNAs (sodium- and chloride-dependent taurine transporter, fibroblast growth factor 13 and tubulin polyglutamylase TTLL7) were significantly associated with OS (P<0.05). Additionally, two lncRNAs (KCNQ1OT1 and MIR17HG) interacted with most of the DEmiRNAs. Notably, two top-ranked miRNAs (hsa-miR-374a-5p and hsa-miR-374b-5p) associated networks were identified to be markedly associated with the pathogenesis. Furthermore, four DEmRNAs (caveolin-1, MET, filamin-A and AKT3) were enriched in the Kyoto Encylopedia of Gene and Genomes pathway analysis, as well as being included in the ceRNA network. In summary, the present results revealed that a specific lncRNA-miRNA-mRNA network was associated with rectosigmoid junction cancer, providing several molecules that may be used as novel prognostic biomarkers and therapeutic targets.

A Postsurgical Prognostic Nomogram for Locally Advanced Rectosigmoid Cancer to Assist in Patient Selection for Adjuvant Chemotherapy.

BACKGROUND: The perioperative treatment model for locally advanced rectosigmoid junction cancer (LARSC) has not been finalized; whether this model should refer to the treatment model for rectal cancer remains controversial. METHODS: We screened 10,188 patients with stage II/III rectosigmoid junction adenocarcinoma who underwent surgery between 2004 and 2016 from the National Cancer Institute Surveillance, Epidemiology, and End Results database. Among them, 4,960 did not receive adjuvant chemotherapy, while 5,228 did receive adjuvant chemotherapy. Propensity score matching was used to balance the two groups for confounding factors, and the Kaplan-Meier method and log-rank test were used for survival analysis. Cox proportional hazards regression analysis was used to identify independent prognostic factors and build a predictive nomogram of survival for LARSC. X-tile software was used to divide the patients into three groups (low, medium, and high) according to their risk scores. 726 patients in our hospital were included for external validation. RESULTS: LARSC patients did not show a benefit from neoadjuvant radiotherapy (P>0.05). After further excluding patients who received neoadjuvant radiotherapy, multivariate analysis found that age, grade, tumor size, T stage, and log odds of positive lymph nodes were independent prognostic factors for patients without adjuvant chemotherapy and were included in the nomogram. The C-index of the model was 0.690 (95% confidence interval: 0.668-0.712). We divided the patients into low, moderate, and high risk subgroups based on prediction scores of the nomogram. We found that adjuvant chemotherapy did not improve the prognosis of low risk patients, while moderate and high risk patients benefited from adjuvant therapy. External validation data found that moderate, and high risk patients also benefited from AT. CONCLUSION: Direct surgery plus adjuvant chemotherapy may be the best perioperative treatment for LARSC. Moreover, adjuvant chemotherapy is only recommended for moderate and high risk patients as it did not benefit low risk patients.

Rectosigmoid-Junction Squamous Cell Carcinoma With pMMR/MSS Achieved a Partial Response Following PD-1 Blockade Combined With Chemotherapy: A Case Report.

Colorectal squamous cell carcinoma (SCC) is extremely rare and associated with a poor prognosis. And the pMMR/MSS colorectal cancer is related to a limited response to programmed death ligand-1 (PD-1) blockade monotherapy. However, the clinical activity of PD-1 blockade monotherapy or combination therapy in colorectal SCC is unknown. One patient with rectosigmoid-junction SCC was treated with PD-1 blockade combined with chemotherapy. After 3 months of PD-1 blockade and chemotherapy, the computed tomography imaging showed that this patient achieved a partial response. The next generation sequencing and immunohistochemistry analysis showed that the patient had tumors with proficient mismatch repair (pMMR) and microsatellite stability (MSS), strong PD-L1 expression, and tumor mutational burden-high (TMB-High), respectively. This case suggests that PD-1 blockade combined with chemotherapy might be an effective therapy for colorectal SCC with pMMR/MSS status. Moreover, the PD-L1 expression and TMB might be the potential predictors of PD-1 blockade response for colorectal SCC patients.

The sigmoid take-off: An anatomical imaging definition of the rectum validated on specimen analysis.

BACKGROUND: A pre-operative imaging landmark to define the rectum would optimise clinical care of rectal cancer patients and research efforts to improve outcomes. The sigmoid take-off has been suggested as an imaging landmark for the rectosigmoid junction (RSJ). This study aimed to investigate whether this imaging definition of the rectum was validated by surgical specimen analysis. METHODS: This prospective study recruited 20 patients undergoing surgery and undertook radiological and pathological analysis of their rectal specimens. The radiological landmark of the sigmoid take-off was identified on pre-operative magnetic resonance imaging (MRI), and the distance to the anterior peritoneal reflection was measured by two readers. After surgery, the distance from the beginning of the sigmoid mesocolon to the anterior peritoneal reflection to the beginning of the sigmoid mesocolon on the specimen was measured, and compared to the distance on MRI using Pearson's Correlation Coefficient and Bland-Altman plots. RESULTS: In 17 patients, the mean distance from the anterior peritoneal reflection to the RSJ on MRI was 20.3 mm and 23.1 mm for two readers, and on pathology was 20.6 mm. The mean differences between MRI and specimen measurements were -0.31 mm (-2.83 to 2.20 mm), and 2.51 mm (95% confidence interval -0.31 to 5.33 mm) for each reader, with correlation coefficients of 0.77 and 0.81. CONCLUSION: The sigmoid take-off has been validated on specimen analysis to be an imaging landmark that defines the termination of the rectum. This anatomical landmark can be used to classify tumours and guide treatment and research of sigmoid colon and rectal cancer.

Rectal NETs and rectosigmoid junction NETs may need to be treated differently.

Neuroendocrine tumors (NETs) are heterogeneous, and the incidence of NETs is rapidly increasing. We observed different survival in patients with rectal NETs and rectosigmoid junction NETs, which are treated similarly. We included patients with rectal and rectosigmoid junction NETs from the SEER database. The 5-year survival was set as the end-point. 6675 patients with rectal NETs and 329 patients with rectosigmoid junction NETs, were eligible for the analysis. Initially, the survival analyses suggested that the 5-year survival significantly differed between the patients with rectal and rectosigmoid junction NETs (HR = 0.82, 95% CI 0.70-0.95; P = .01). Tumor differentiation, an invasion deeper than T2, and lymph node and distant metastases were still important risk factors affecting survival for both location. While, the males showed better survival (HR = 0.69, 95% CI 0.55-0.88; P < .01) and primary tumor surgery had no benefits (P = .56) for patients with rectosigmoid junction NETs. The factors that predict regional lymph node metastases varied by location. In rectal NETs, invasion deeper than T1 and a tumor larger than 1 cm could significantly increase the risk of regional lymph node metastases (all OR > 5, P < .01). In rectosigmoid junction NETs, the risk of regional lymph node metastases was considered significantly higher with invasion deeper than T1 (all OR > 5, P < .01) and a tumor larger than 2 cm (OR = 31.32, 95% CI 2.53-387.57; P < .01). We advocate a clear and consistent definition of the rectosigmoid junction for future studies, and more studies are needed to determine the reason underlying differences between rectum and rectosigmoid junction.

Comparison of the sigmoid take-off with other definitions of the rectosigmoid junction: A retrospective comparative cohort analysis.

BACKGROUND: The diversity in definitions for the rectosigmoid junction is becoming a major obstacle in standardizing optimal treatment of rectal cancers. The study aimed to determine the average distance of the sigmoid take-off from the anal verge and its association with individual factors. MATERIALS AND METHODS: Patients diagnosed with rectal and sigmoid colon cancer in our centre from January 2010 to December 2018 were retrospectively enrolled in the cancer group. The results of 200 controls without colorectal disease were also reviewed (normal group). The distance of different landmarks and margins of cancer from the anal verge were retrieved from computed tomography (CT), magnetic resonance imaging (MRI), and endoscopy findings. RESULTS: The cancer group comprised 635 patients (381 men, median age: 64 years). The average distances of the sigmoid take-off from the anal verge measured in CT and MRI were comparable (P = 0.483). On MRI, the average distance of the sigmoid take-off from the anal verge in the cancer group was comparable with that of the normal group (P = 0.070). Multivariate regression revealed that the distance of the sigmoid take-off from the anal verge was associated with the distances of the sacral promontory (P < 0.001) and peritoneal reflection (P < 0.001) from the anal verge. CONCLUSION: The cancer distributions of patients varied widely with the application of different definitions. The point of sigmoid take-off is an intuitive landmark influenced by individual factors. The measurement of the sigmoid take-off by different researchers in both CT and MRI revealed good consistency. Further studies regarding the clinical significance of this definition are still needed.

Mucosal Schwann Cell Hamartoma of the Rectosigmoid Junction: A Rare Lesion Mimicking Mucosal Prolapse Syndrome and Other Neural Lesions.

In this article, we report the case of a 40-year-old woman with a sessile polyp of the rectosigmoid junction that underwent endoscopic resection. The resected specimen showed spindle cell proliferation with eosinophilic cytoplasm between mucosal crypts, mimicking mucosal prolapse syndrome. However, these were immunohistochemically positive for S-100, indicating neural cell origin. As neural polypoid lesion of the rectum, neurofibroma, perineurioma, schwannoma, and mucosal Schwann cell hamartoma were in the differential diagnosis. Histology and additional immunohistochemistry confirmed mucosal Schwann cell hamartoma. Mucosal Schwann cell hamartoma of the rectosigmoid junction or rectum can be a histological mimic of mucosal prolapse syndrome and other S-100 positive neural cell lesions; however, the lesion in the present case was correctly diagnosed with histology and immunohistochemistry.

Oncological outcome of carcinomas in the rectosigmoid junction compared to the upper rectum or sigmoid colon - A retrospective cohort study.

INTRODUCTION: Although carcinomas of the rectosigmoid junction are frequent, specific data on these tumors are sparse because assignment either to the colon or rectum is common. The objective of this study is to determine whether carcinomas of the rectosigmoid junction can be assigned to the sigmoid colon or to the upper rectum in terms of tumor characteristics and oncological outcome. MATERIALS AND METHODS: 337 consecutive patients undergoing resection of carcinomas in the sigmoid colon, the rectosigmoid junction and the upper third of the rectum were analyzed retrospectively and additionally followed-up for oncological outcome. RESULTS: 185 patients (54.9%) showed carcinoma in the sigmoid colon, 41 (12.2%) in the rectosigmoid junction and 111 (32.9%) in the upper rectum. Synchronous liver metastases (rectosigmoid junction 31.7%, sigmoid colon 16.2%, upper rectum 11.7%; P = 0.01), lymphovascular invasion (rectosigmoid junction 46.3%, sigmoid colon 25.4%, upper rectum 32.4%; P = 0.03) and pN2 (rectosigmoid junction 31.7%, sigmoid colon 10.3%, upper rectum 13.5%; P = 0.002) were more common in carcinomas of the rectosigmoid junction. The median follow-up period was 44 (22-75.5) months. Five-year overall survival was 44.6% in patients with carcinomas in the rectosigmoid junction, 70.9% in the sigmoid colon, and 70.2% in the upper rectum. CONCLUSION: Carcinomas of the rectosigmoid junction reveal a deviant behavioral pattern compared to its adjacent bowel segments.

Radiotherapy dose led to a substantial prolongation of survival in patients with locally advanced rectosigmoid junction cancer: a large population based study.

Radiotherapy is widely applied for locally advanced rectal cancer (RC) to improve both local control and long-term outcomes. However, the efficacy of radiotherapy for rectosigmoid junction cancer (RSC) is still undetermined. Here, we identified 10074 patients who were diagnosed with locally advanced RSC from Surveillance, Epidemiology, and End-Results (SEER) cancer registry. These patients were divided into three subgroups according to different therapy strategies, including surgery alone, surgery plus preoperative radiotherapy and surgery plus postoperative radiotherapy. 5-year cancer-specific survival (CSS) and 5-year overall survival (OS) were obtained. Kaplan-Meier methods and Cox regression models were used to estimate the correlations between prognostic factors and survival outcomes.The 5-year CSSs for RSC patients treated with pre- and postoperative radiotherapy were 72.3% and 72.2%, which were significantly higher than surgery alone (64.8%). The 5-year OSs for RSC patients treated with pre- and postoperative radiotherapy were 71.6% and 71.2%, which were higher than surgery alone (64.0%). In the separate analyses of stage II and III RSC patients, the similar trends were also obtained. In addition, pre- and postoperative radiotherapy were equally identified as valuable prognostic factors for better survival outcomes in RSC patients. Furthermore, the results following propensity score matching also confirmed that the long-term survivals of RSC patients were improved following radiotherapy. In conclusion, locally advanced RSCpatients could obtain potential long-term survival benefits from radiotherapy. A prospective randomized control trial should be performed to further validate the strength of evidence in current study.

Diffuse large B cell lymphoma of the rectosigmoid junction: case report and literature review.

Primary colorectal lymphoma (PCL) is a rare condition that accounts for asmall percentage of all gastrointestinal (GI) malignancies. There are severalreports in the literature regarding the most common features of PCL. However,primary lymphoma in the rectosigmoid junction has been rarely reported. Ourcase was a 67-year-old male who presented with non-specific symptoms ofbowel obstruction which, upon further workup, was diagnosed as a rare case ofPCL located in the rectosigmoid junction.