Abstract 334P
Background
This research sought to explore the prognostic value and beneficiary of adjuvant radiotherapy for patients with non-metastatic stage T4 sigmoid colon cancer, providing the basis for the formulation of the clinical treatment strategy.
Methods
The data of 4,979 patients with stage T4N0-2M0 sigmoid colon cancer in the Surveillance, Epidemiology, and End Results database from 2004 to 2016 were retrospectively analyzed. Propensity score matching (PSM) with a ratio of 1 to 2 was executed to eliminate the difference in variable distribution among groups. Cox regression and subgroup analyses were used to explore the effect of postoperative radiotherapy on overall survival (OS).
Results
Patients were divided into surgery followed adjuvant radiotherapy group (430 cases, 8.6%) and surgery alone group (4,549 cases, 91.4%). Both before PSM and after PSM, adjuvant radiotherapy could significantly prolong the OS (all p < 0.05). After PSM, the 1-, 3-, and 5-year OS rates for patients underwent adjuvant radiotherapy or not were 94.6% vs. 87.9%, 71.4% vs. 67.4%, and 60.4% vs. 54.6%, respectively. And the median OS was 86 months and 74 months, respectively. Multivariate analysis showed that adjuvant radiotherapy independently served as a predictor of OS (hazard ratio = 1.529, 95% confidence interval: 1.194-1.996, p = 0.004). Subgroup analysis illustrated those patients with poorly differentiated or undifferentiated tumors, tumor size ≥ 5cm or stage T4b were the beneficiaries of adjuvant radiotherapy (all p < 0.05).
Conclusions
Adjuvant radiotherapy for stage T4N0-2M0 sigmoid colon cancer could significantly prolong the OS and might be recommended for potential beneficiaries.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Junxin Wu.
Funding
National Clinical Key Specialty Construction Program; Fujian Province Natural Science Foundation.
Disclosure
All authors have declared no conflicts of interest.