Neoadjuvant chemoradiotherapy for patients with unresectable radically locally advanced colon cancer: a potential improvement to overall survival and decrease to multivisceral resection.

Background: The management of unresectable locally advanced colon cancer (LACC) remains controversial, as resection is not feasible. The goal of this study was to evaluate the treatment outcomes and toxicity of neoadjuvant chemoradiotherapy (NACRT) followed with surgery and adjuvant chemotherapy in patients with unresectable radically LACC.
Methods: We included patients who were diagnosed at our institution, 2010-2018. The neoadjuvant regimen consisted of radiotherapy and capecitabine/ 5-fluorouracil-based chemotherapy.
Results: One hundred patients were identified. The median follow-up time was 32 months. The R0 resection rate, adjusted nonmultivisceral resection rate and bladder preservation rate were 83.0, 43.0 and 83.3%, respectively. The pCR and clinical-downstaging rates were 18, and 81.0%%, respectively. The 3-year PFS and OS rates for all patients were 68.6 and 82.1%, respectively. Seventeen patients developed grade 3-4 myelosuppression, which was the most common adverse event observed after NACRT. Tumor perforation occurred in 3 patients during NACRT. The incidence of grade 3-4 surgery-related complications was 7.0%. Postoperative anastomotic leakage was observed in 3 patients.
Conclusions: NACRT followed by surgery was feasible and safe for selected patients with LACC, and can be used as a conversion treatment to achieve satisfactory downstaging, long-term survival and quality of life, with acceptable toxicities.