- - - Department of Radiation Oncology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- - - Department of Radiation Oncology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- - - Department of Radiation Oncology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- - - Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran

Background & Objective: Currently, neoadjuvant chemoradiotherapy, followed by surgery, is the standard treatment for locally advanced rectal cancer. The use of induction chemotherapy for this tumor is controversial. In this study, the benefits and side effects of induction chemotherapy in locally advanced rectal cancer are evaluated.Methods: Twenty-nine patients with locally advanced rectal cancer in ۲۰۱۸-۲۰۱۹ were enrolled in this study. Initially, they underwent induction chemotherapy (oxaliplatin ۱۳۰ mg/m۲ every ۳ weeks and capecitabine ۱۰۰۰ mg/m۲ twice a day for ۱۴ days every ۳ weeks for ۲ courses). Then, neoadjuvant chemoradiotherapy (radiotherapy ۵۰.۴ Gy/۲۸ for ۵ days a week concomitant with weekly oxaliplatin ۵۰ mg/m۲, as well as capecitabine ۸۲۵ mg/m۲/bid on the days of radiotherapy) was administered. After ۴ weeks, computed tomography (CT) scan of thorax, pelvis, and abdomen with and without contrast was performed. Total mesorectal surgery was performed ۶-۸ weeks after the end of radiotherapy. Four courses of adjuvant chemotherapy were applied. Pathologic complete response (pCR), margin, sphincter preservation, and adverse effects were assessed.Results: In this study, pCR was present in ۶ (۲۰.۷%) patients. R۰ resection was done in ۹۶.۰۵%. Sphincter was preserved in ۴۴.۴% of lower rectal tumors. Two patients (۶.۹%) did not complete adjuvant treatment. Grade ۳ adverse effects were documented in ۱۳.۷% of cases during induction chemotherapy and ۱۷.۲% of cases during neoadjuvant chemoradiation. Mortality was not reported.Conclusion: Induction chemotherapy, followed by neoadjuvant chemoradiotherapy and surgery, would be an effective and safe modality in locally advanced rectal cancer.

Induction chemotherapy, Neoadjuvant chemoradiotherapy, surgery, Locally advanced rectal cancer