Preoperative radiotherapy (RT) alone or with chemotherapy (CRT) has become the current standard for locally advanced rectal cancers. In the era of total mesorectal excision (TME), neoadjuvant RT/CRT has not shown a benefit on OS. Adjuvant chemotherapy or further maintenance therapy may have a promising role in influencing the survival of patients with ypStage III rectal cancer. Although adjuvant chemotherapy for ypStage III rectal cancer after preoperative RT or CRT and curative surgery is recommended in the National Comprehensive Cancer Network (NCCN) guideline, maintenance treatment with monthly tegafur-uracil following adjuvant chemotherapy for improved survival of colorectal cancer is uncommon and lacks evidence.
The retrospective enrollment analyzed 259 patients with locally advanced rectal cancer, defined as T3 or T4 or node-positive according to the TNM system. All patients received preoperative RT at Chang Gung Medical Foundation, Chiayi Branch, from January 2006 through December 2015. Total 102 patients with ypStage III rectal cancer were enrolled from among 259 patients for further study.
The median follow-up duration in this study was 62.6 months. The enrolled patients included 59 men and 43 women. The mean ages in the maintenance and observation groups were 62.2 and 65.7 years, respectively. The maintenance group had significantly better three-year DFS than that of the observation group (84.6% vs. 64.5%, p = 0.023). However, the five-year cancer-specific survival did not differ significantly between the maintenance and observation groups (81.2% vs. 75.7%, p = 0.385). Multivariate analysis with forward stepwise regression confirmed that lower rectal cancer (< 6 cm from the anal verge), metastatic lymph nodes ratio (≥ 0.3), and tegafur-uracil maintenance (≥ 6 cycles) were independent prognostic factors for three-year DFS. Patients with a higher location of rectal cancer wound (≥ 6 cm) had a significant survival benefit from tegafur-uracil maintenance (p = 0.023).
Adding monthly tegafur-uracil (≥ 6 cycles) following fluorouracil-based adjuvant chemotherapy potentially could improve the three-year DFS in patients with ypStage III rectal cancer.
Cancer Registry of the Chang Gung Medical Foundation of Chiayi.
Clinical trial identification
Legal entity responsible for the study
Institutional Review Board of Chang Gung Memorial Hospital (IRB No.: 201601450B0).
Has not received any funding.
The author has declared no conflicts of interest.