A retrospective study on the impact of the number of resected lymph nodes on the survival outcome of stage IV rectal cancer patients after preoperative therapy

[摘要] Background: There is no consensus on the optimal number of examined LNs for stage IV rectal cancer patients after preoperative therapy. We aimed to explore the impact of the number of resected lymph nodes (LNs) on the survival outcomes of stage IV rectal cancer patients after preoperative therapy. Methods: Clinicopathologic data of 556 patients diagnosed with stage IV rectal cancer between 1st January, 2010 and 31st December, 2015 from the Surveillance, Epidemiology, and End Results (SEER) database after preoperative therapy were reviewed. The patients were further divided into two groups: the ≥15 resected LNs group and <15 resected LNs group based on the X-tile software analysis results of the number of resected LNs. Results: Both univariate and multivariate regression analyses revealed that the number of resected LNs and N status were significantly positively correlated with the survival outcome of the patients. Patients in the ≥15 resected LNs group had a significant better cancer-specific survival (CSS) (P=0.003) than those in the <15 resected LNs group. The 3-year CSS rate was 63.2% for patients with ≥15 resected LNs compared with 55.7% for those with <15 resected LNs. The 5-year CSS rate was 50.2% and 30.5% for patients in the ≥15 resected LNs group and those in the <15 resected LNs group, respectively. Conclusions: The number of resected LNs is an important independent prognostic factor that influences the survival outcome of stage IV rectal cancer patients after receiving preoperative therapy.

[学科分类] 肿瘤学

[关键词] Rectal cancer;number of resected lymph nodes;stage IV;Survival, Surveillance, Epidemiology, and End Results database (SEER database)