{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T19:55:42Z","timestamp":1789156542741,"version":"build-2803163510"},"reference-count":15,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T00:00:00Z","timestamp":1784160000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background: Mucinous adenocarcinoma (MAC) of the colorectum is a biologically distinct histological subtype whose prognostic significance may vary substantially according to primary tumor location. The impact of anatomical site on clinicopathological characteristics and long-term survival in MAC remains incompletely characterized. This study aimed to evaluate the influence of tumor location on oncological outcomes in patients with mucinous colorectal cancer using a large population-based dataset. Methods: Patients diagnosed with mucinous colorectal adenocarcinoma between 2000 and 2023 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Operated patients were stratified by anatomical location into three groups: right colon (cecum, ascending colon, hepatic flexure, transverse colon), left colon (splenic flexure, descending colon, sigmoid colon, rectosigmoid junction), and rectum. The primary endpoints were overall survival (OS) and cancer-specific survival (CSS). Survival analyses were performed using the Kaplan\u2013Meier method with log-rank testing. Multivariable Cox proportional hazards regression was used to assess the independent association of tumor location with survival outcomes, adjusting for age at diagnosis, year of diagnosis, sex, AJCC (American Joint Committee on Cancer) stage, tumor grade, receipt of radiotherapy and chemotherapy. Temporal trends in survival were evaluated across four consecutive diagnostic periods: 2000\u20132005, 2006\u20132011, 2012\u20132017, and 2018\u20132023. Results: A total of 40,698 patients with mucinous colorectal cancer were identified, of whom 40,174 underwent cancer-directed surgery (right colon n = 25,317; left colon n = 10,408; rectum n = 4449). The right colon was the predominant site of disease (62.9%). Median age was highest in the right colon group (74.0 years) and lowest in the rectum (65.0 years), while female sex predominated in right-sided tumors (55.7%) and male sex in rectal tumors (61.1%). Chemotherapy and radiotherapy utilization were markedly higher in the rectal group (68.6% and 64.5%, respectively) compared with the right colon (28.8% and 1.1%). Median OS was equivalent in the right and left colon groups (87.0 months each) but declined to 80.0 months in the rectal group. All pairwise CSS comparisons were statistically significant (all p &lt; 0.001). On multivariable analysis, using the right colon as reference, the adjusted hazard ratios for CSS were 1.33 (95% CI: 1.28\u20131.39) for the left colon and 1.45 (95% CI: 1.34\u20131.57) for the rectum (both p &lt; 0.001). Despite receiving the highest rates of multimodal therapy, rectal MAC demonstrated the worst long-term CSS across all anatomical groups. Temporal analyses revealed consistent CSS improvements in right-sided and left-sided MAC over the study period, whereas rectal MAC showed a non-linear trajectory with a plateau in the most recent diagnostic cohort (2018\u20132023). Conclusions: Mucinous colorectal adenocarcinoma demonstrates substantial biological and prognostic heterogeneity according to anatomical tumor location. Right-sided MAC was the most prevalent subtype and exhibited superior cancer-specific survival despite older patient age and lower treatment intensity. Rectal MAC demonstrated the worst long-term outcomes despite high utilization of multimodal neoadjuvant therapy, consistent with the established reduced responsiveness of mucinous tumors to conventional chemoradiotherapy. These findings underscore the necessity of incorporating anatomical location and tumor biology into individualized risk stratification and therapeutic planning for patients with mucinous colorectal cancer.<\/jats:p>","DOI":"10.3390\/jcm15145584","type":"journal-article","created":{"date-parts":[[2026,7,17]],"date-time":"2026-07-17T03:12:38Z","timestamp":1784257958000},"page":"5584","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Anatomical Location Is Associated with Clinicopathological Features and Long-Term Oncological Outcomes in Mucinous Colorectal Adenocarcinoma: A Population-Based Analysis of 40,698 Patients from the SEER Database"],"prefix":"10.3390","volume":"15","author":[{"given":"Burak","family":"Kutlu","sequence":"first","affiliation":[{"name":"General Surgery, Ac\u0131badem Ankara Hospital, 06450 Ankara, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"\u00c7i\u011fdem","family":"Benlice","sequence":"additional","affiliation":[{"name":"General Surgery, Istanbul Health and Technology University, 34275 Istanbul, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1637","DOI":"10.1136\/gutjnl-2014-309086","article-title":"Colorectal cancer screening: A global overview of existing programmes","volume":"64","author":"Schreuders","year":"2015","journal-title":"Gut"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1186\/s40880-019-0361-0","article-title":"Mucinous colorectal adenocarcinoma: Clinical pathology and treatment options","volume":"39","author":"Luo","year":"2019","journal-title":"Cancer Commun."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"182","DOI":"10.1111\/his.13975","article-title":"The 2019 WHO classification of tumours of the digestive system","volume":"76","author":"Nagtegaal","year":"2020","journal-title":"Histopathology"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"18682","DOI":"10.1038\/s41598-024-69916-0","article-title":"Clinicopathological features and prognosis analysis of proximal colonic mucinous adenocarcinoma","volume":"14","author":"Han","year":"2024","journal-title":"Sci. Rep."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1461","DOI":"10.4251\/wjgo.v15.i8.1461","article-title":"Epidemiologic characteristics and risk factors associated with overall survival for patients with mucinous colorectal cancer: A population-based study","volume":"15","author":"Jiang","year":"2023","journal-title":"World J. Gastrointest. Oncol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1007\/s10151-025-03225-0","article-title":"Clinicopathological features and prognosis of patients with colorectal Mucinous adenocarcinoma mixed with other pathological components: A nationwide retrospective study in China","volume":"29","author":"Yuan","year":"2025","journal-title":"Tech. Coloproctol."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Lan, Y.-T., Chang, S.-C., Lin, P.-C., Lin, C.-C., Lin, H.-H., Huang, S.-C., Lin, C.-H., Liang, W.-Y., Chen, W.-S., and Jiang, J.-K. (2021). Clinicopathological and Molecular Features of Colorectal Cancer Patients with Mucinous and Non-Mucinous Adenocarcinoma. Front. Oncol., 11.","DOI":"10.3389\/fonc.2021.620146"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1350","DOI":"10.1038\/nm.3967","article-title":"The consensus molecular subtypes of colorectal cancer","volume":"21","author":"Guinney","year":"2015","journal-title":"Nat. Med."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"16","DOI":"10.21037\/jgo-2025-627","article-title":"Clinicopathological characteristics and prognosis of patients with mucinous adenocarcinoma originating from the left colon, right colon, or rectum: A nationwide retrospective study in China","volume":"17","author":"Liu","year":"2026","journal-title":"J. Gastrointest. Oncol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1186\/1477-7819-10-109","article-title":"The clinicopathological features of colorectal mucinous adenocarcinoma and a therapeutic strategy for the disease","volume":"10","author":"Numata","year":"2012","journal-title":"World J. Surg. Oncol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2794","DOI":"10.1007\/s00261-024-04743-5","article-title":"Prediction of mucinous adenocarcinoma in colorectal cancer with mucinous components detected in preoperative biopsy diagnosis","volume":"50","author":"Ling","year":"2024","journal-title":"Abdom. Radiol."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Vernmark, K., Sun, X.-F., and Holmqvist, A. (2020). Mucinous and Non-Mucinous Rectal Adenocarcinoma\u2014Differences in Treatment Response to Preoperative Radiotherapy. J. Pers. Med., 10.","DOI":"10.3390\/jpm10040226"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"719","DOI":"10.1007\/s12029-020-00460-6","article-title":"The Impact of Histologic Subtype on Receipt of Adjuvant Chemotherapy and Overall Survival in Stage III Colon Cancer: A Retrospective Cohort Analysis","volume":"52","author":"Powers","year":"2021","journal-title":"J. Gastrointest. Cancer"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"563","DOI":"10.1007\/s00384-013-1826-2","article-title":"Overall survival is improved in mucinous adenocarcinoma of the colon","volume":"29","author":"Hogan","year":"2014","journal-title":"Int. J. Colorectal Dis."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1109","DOI":"10.3892\/ijo_00000238","article-title":"Survival of patients diagnosed with either colorectal mucinous or non-mucinous adenocarcinoma: A population-based study in Canada","volume":"34","author":"Xie","year":"2009","journal-title":"Int. J. Oncol."}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/15\/14\/5584\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,17]],"date-time":"2026-07-17T03:48:10Z","timestamp":1784260090000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/15\/14\/5584"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,16]]},"references-count":15,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["jcm15145584"],"URL":"https:\/\/doi.org\/10.3390\/jcm15145584","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,16]]}}}