Tumor deposits: markers of poor prognosis in patients with locally advanced rectal cancer following neoadjuvant chemoradiotherapy

// Lu-Ning Zhang 1,* , Wei-Wei Xiao 1,* , Shao-Yan Xi 4,* , Pu-Yun OuYang 1,* , Kai-Yun You 5 , Zhi-Fan Zeng 1 , Pei-Rong Ding 2 , Hui-Zhong Zhang 4 , Zhi-Zhong Pan 2 , Rui-Hua Xu 3,** and Yuan-Hong Gao 1,** 1 Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China 2 Department of Colorectal Surgery, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China 3 Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China 4 Department of Pathological Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong, China 5 Department of Oncology, The Second Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China * Co-first authors ** Co-senior authors Correspondence to: Yuan-Hong Gao, email: // Rui-Hua Xu, email: // Keywords : adjuvant chemotherapy; locally advanced rectal cancer; neoadjuvant chemoradiotherapy; prognosis; tumor deposits Received : July 20, 2015 Accepted : November 25, 2015 Published : December 18, 2015 Abstract Background: Tumor deposits (TDs) were reported to be poor prognoses in colorectal carcinoma, but the significance in locally advanced rectal cancer (LARC) (T3-4/N+) following neoadjuvant chemoradiotherapy (neo-CRT) and surgery is unclear. Since adjuvant chemotherapy showed no benefit for LARC following neo-CRT, it is of great value to investigate whether TDs can identify the subgroup of patients who may benefit from adjuvant chemotherapy. Methods: Between 2004 and 2012, 310 LARC patients following neo-CRT and surgery were retrospectively reviewed. Overall survival (OS), disease-free survival (DFS), distant metastasis free survival (DMFS) and local recurrence free survival (LRFS) were evaluated by Kaplan-Meier method, log-rank test and Cox models. Results: TDs-positive patients showed adverse OS, DFS and DMFS (all P ≤0.001), but not LRFS ( P = 0.273). In multivariate analysis, TDs continued to be associated with poor OS (HR = 2.44, 95% CI 1.32-4.4, P = 0.004) and DFS (HR = 1.99, 95% CI 1.21-3.27, P = 0.007), but not DMFS (HR = 1.77, 95% CI 0.97-3.20, P = 0.061) or LRFS (HR = 1.85, 95% CI 0.58-5.85, P = 0.298). Among TDs-positive patients, adjuvant chemotherapy significantly improved OS ( P = 0.045) and DMFS ( P = 0.026), but not DFS ( P = 0.127) or LRFS ( P = 0.862). Conclusions: TDs are predictive of poor survival in LARC after neo-CRT. Fortunately, TDs-positive patients appear to benefit from adjuvant chemotherapy.