Neoadjuvant chemoradiotherapy in patients with unresectable locally advanced sigmoid colon cancer: clinical feasibility and outcome.

Background: Patients with locally advanced sigmoid colon cancer (LASCC) have limited treatment options and a dismal prognosis with poor quality of life. This retrospective study aimed to further evaluate the feasibility and efficacy of neoadjuvant chemoradiotherapy (NACRT) followed by surgery as treatment for select patients with unresectable LASCC.

Methods: We studied patients with unresectable LASCC who received NACRT between November 2010 and April 2019. The NACRT regimen consisted of intensity modulated radiotherapy (IMRT) of 50 Gy to the gross tumor and positive lymphoma node and 45 Gy to the clinical target volume. Capecitabine‑based chemotherapy was administered every 2 (mFOLFOX6) or 3 weeks (CAPEOX). Surgery was scheduled 6-8 weeks after radiotherapy.

Results: Seventy‑two patients were enrolled in this study. Patients had a regular follow-up (median, 41.1 months; range, 8.3-116.5 months). Seventy‑one patients completed NACRT, and sixty-five completed surgery. Resection with microscopically negative margins (R0 resection) was achieved in 64 patients (88.9%). Pathologic complete response was observed in 15 patients (23.1%), and multivisceral resection was necessary in 38 patients (58.3%). The cumulative probability of 3-year overall survival (OS) and progression-free survival (PFS) were 75.8 and 70.7%, respectively.

Conclusions: For patients with unresectable LASCC, neoadjuvant chemoradiotherapy is feasible, surgery can be performed safely and may result in increased survival and organ preservation rates.