Short-Course Versus Long-Course Neoadjuvant Chemoradiotherapy in Patients With Rectal Cancer: Preliminary Results of a Randomized Controlled Trial Publisher

Summary: Short-course vs long-course chemoradiotherapy for rectal cancer showed no major differences in toxicity or response. Can treatment type impact outcomes? Findings suggest both are viable. #ColorectalCancer #Chemotherapy

Aghili M¹ ; Khalili N² ; Khalili N² ; Babaei M¹ ; Farhan F¹ ; Haddad P¹ ; Salarvand S³ ; Keshvari A⁴ ; Fazeli MS⁴ ; Mohammadi N¹ ; Ghalehtaki R¹
Source: Radiation Oncology Journal Published:2020

Abstract

Purpose: Colorectal cancer is becoming an increasing concern in the middle-aged population of Iran. This study aimed to compare the preliminary results of short-course and long-course neoadjuvant chemoradiotherapy treatment for rectal cancer patients. Materials and Methods: In this clinical trial we recruited patients with rectal adenocarcinoma located from 5 cm to 15 cm above the anal verge. Patients in group I (short-course) received three-dimensional conformational radiotherapy with a dose of 25 Gy/5 fractions in 1 week plus concurrent XELOX regimen (capecitabine 625 mg/m2 from day 1–5 twice daily and oxaliplatin 50 mg/m2 on day 1 once daily). Patients in group II (long-course) received a total dose of 50–50.4 Gy/25–28 fractions for 5 to 5.5 weeks plus capecitabine 825 mg/m2 twice daily. Both groups underwent consolidation chemotherapy followed by delayed surgery at least 8 weeks after radiotherapy completion. The pathological response was assessed with tumor regression grade. Results: In this preliminary report on complications and pathological response, 66 patients were randomized into two study groups. Mean duration of radiotherapy in the group II (long-course) was 5 ± 1 days (range, 5 to 8 days) and 38 ± 6 days (range, 30 to 58 days). The median follow-up was 18 months. Pathological complete response was achieved in 32.3% and 23.1% of patients in the shortcourse and long-course groups, respectively (p = 0.558). Overall, acute grade 3 or higher treatment-related toxicities occurred in 24.2% and 22.2% of patients in group I and II, respectively (p = 0.551). No acute grade 4 or 5 adverse events were observed in either group except one grade 4 hematologic toxicity that was seen in group II. Within one month of surgery, no significant difference was seen regarding grade ≥3 postoperative complications (p = 0.333). Conclusion: For patients with rectal cancer located at least 5 cm above the anal verge, short-course radiotherapy with concurrent and consolidation chemotherapy and delayed surgery is not different in terms of acute toxicity, postoperative morbidity, complete resection, and pathological response compared to long-course chemoradiotherapy. © 2020 The Korean Society for Radiation Oncology.