Outcomes of preoperative chemoradiotherapy after complete smoking cessation followed by total mesorectal excision with selective lateral pelvic lymph node dissection for locally advanced low rectal cancer

Abstract Purpose: Outcomes of patients with rectal cancer who underwent preoperative chemoradiotherapy after complete smoking cessation are unknown. We evaluated the outcomes of patients with locally advanced low rectal cancer who underwent combined preoperative chemoradiotherapy after complete smoking cessation and total mesorectal excision with selective lateral lymph node dissection. Predictive factors associated with response to preoperative chemoradiotherapy were investigated. Methods: In this retrospective study at a tertiary medical center, 160 patients with locally advanced low rectal cancer who underwent surgical resection during January 2014–December 2019 were enrolled; data of 28 with stage II or III rectal cancer who underwent preoperative chemoradiotherapy and surgery were analyzed. Before chemoradiotherapy, a Smokerlyzer was used to measure expiratory carbon monoxide and monitor smoking cessation. Pathologic response rate and oncological outcomes were analyzed. Results: No major post-surgical complications occurred. Pathologic complete response was achieved in 8/28 patients (28.6%). Three-year recurrence-free and overall survival rates were 81.4% and 92.4%, respectively. No patient developed local recurrence in lateral pelvic lymph nodes. Survival did not differ significantly between patients with and without pathologic complete response. In univariate and multivariate analyses, pretreatment hemoglobin (>13.0) [hazard ratio: 7.00 (95% confidence interval, 1.090–45.20); p=0.0408] and clinically negative N stage before treatment [hazard ratio: 18.9 (95% confidence interval, 1.63–218.0); p=0.0187] were significantly associated with pathologic complete response. Conclusion: Preoperative chemoradiotherapy with complete smoking cessation followed by total mesorectal excision with selective lateral lymph node dissection was safely performed and resulted in high pathologic complete response rates and favorable survival outcomes.