Toxicity, Disease Control, and Survival Outcomes of Intensified Preoperative Chemoradiotherapy in Patients with Locally Advanced Rectal Cancer: A Single-Institution Study

Purpose: The standard treatment regimen of preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC) is still controversial. The purpose of this study was to analyze the efficacy and safety of preoperative intensive CRT in our institution. Methods: A retrospective data collection and analysis of 181 LARC patients receiving oxaliplatin (85%) of standard doses in capecitabine-based preoperative CRT and two additional cycle of neoadjuvant chemotherapy between the end of concurrent CRT and surgery.Results: The compliance of the preoperative CRT was satisfactory with 99.4%patients completed radiotherapy and 97.19%patients completed all 2 cycles of concurrent chemotherapy. Except for 20 patients diagnosed clinical complete remission (cCR) managed according to watch and wait strategy, 160 patients received R0 radical surgery. The pathological complete response (pCR) rate was 23.75% (38/160) and tumor regression grade (TRG) 0/1 was 40% (72/180). In terms of tumor downstaging, 89 (55.63%) had T downstaging while 115 (71.88%) had N downstaging. The 1-overall survival (OS),2-OS,3-OS and 5-OS were 98.7%, 96.5%, 91.4% and 81.5%, respectively. The total rate of sphincter preservation was 86.25% (138/160) and the rate of patients with low rectal cancer was 73.0% (54/74) without affecting local control rates and survival rates. Both acute adverse reactions to preoperative CRT and postoperative complications were tolerable and controllable.Conclusion: In this retrospective study, preoperative intensive CRT of patients with LARC achieved satisfied disease control and survival outcomes and well acquired the sphincter retention rate in recent years in our institution. On the basis of these findings, a Phase III study to definitively test the intensified preoperative CRT strategy is warranted.