Short-course versus long-course neoadjuvant chemoradiotherapy in patients with rectal cancer: preliminary results of a randomized controlled trial

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: Patients in group I 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 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 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 study groups. Mean duration of radiotherapy in the two groups 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 short-course 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. 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 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.

Keywords: Chemoradiotherapy; Clinical trial; Consolidation chemotherapy; Dose hypofractionation; Iran; Rectal Neoplasms.

Fig. 1.

CONSORT flow diagram of the study. AV, anal verge; PS, performance score; ChT, chemoradiotherapy; FAP, familial adenomatous polyposis; ITT, intention-to-treat.