Comparison of oncologic outcomes of metastatic rectal cancer patients with or without neoadjuvant chemoradiotherapy

The aim of this study is to evaluate the effect of neoadjuvant chemoradiotherapy in stage IV rectal cancer.

Primary rectal cancer patients with synchronous distant metastases between September 2001 and August 2011 were enrolled. Of 86 patients, 40 patients underwent neoadjuvant chemoradiotherapy (RTX group) and the remaining 46 patients underwent postoperative systemic chemotherapy without radiotherapy (NRTX group). Sharp mesorectal excision according to tumor location was performed. Oncologic outcomes were compared.

The lower tumor location was more common in RTX group than NRTX group (60.0 vs. 28.3%, P = 0.003). Clinical T and N status and American Society of Anesthesiologist (ASA) score were similar in both groups. The incidence of pathologic LN metastases in the NRTX group was 93.5% compared with 70.0% in RTX group (P = 0.007). Pattern of distant metastasis was similar between groups. However, metastatectomy was frequently performed in RTX group than NRTX group (57.5 vs. 30.4%, P = 0.020). There was no statistical difference in local recurrence rate between groups (10.0% in RTX vs. 15.2% in NRTX, P = 0.470). The median PFS was similar in both groups (12.00 months in RTX vs. 12.00 months in NRTX, P = 0.768). The median OS between groups was also not different (24.00 months in RTX vs. 27.00 months in NRT, P = 0.510).

Neoadjuvant chemoradiotherapy may not affect local control and overall survival in locally advanced rectal cancer with distant metastasis.