Comparative Outcomes of Neoadjuvant Treatment Prior to Total Mesorectal Excision and Total Mesorectal Excision Alone in Selected Stage II/III Low and Mid Rectal Cancer.

Background: Current guidelines advocate that all rectal cancer patients with American Joint Committee on Cancer (AJCC) stages II and III disease should be subjected to neoadjuvant therapy. However, improvements in surgical technique have resulted in single-digit local recurrence rates with surgery only.
Methods: Operative, postoperative, and oncological outcomes of patients with and without neoadjuvant therapy were compared between January 2002 and December 2013. For this purpose, all patients resected with low anterior rectal resection (LAR) and total mesorectal excision (TME) who had or had not been irradiated were identified from the authors' prospectively maintained database. Patients who were excluded were those with high rectal cancer or AJCC stage IV disease; in the surgery-only group, patients with AJCC stage I disease or with pT4Nx rectal cancer; and in the irradiated patients, patients with ypT4Nx or cT4Nx rectal cancer.
Results: Overall, 454 consecutive patients were included. A total of 342 (75 %) patients were irradiated and 112 (25 %) were not irradiated. Median follow-up for all patients was 48 months. Among patients with and without irradiation, pathological circumferential resection margin positivity rates (2.9 vs. 1.8 %, p = 0.5) were not different. At 5 years, in irradiated patients compared with surgery-only patients, the incidence of local recurrence was decreased (4.5 vs. 3.8 %, p = 0.5); however, systemic recurrences occurred more frequently (10 vs. 17.8 %, p = 0.2). Irradiation did not affect overall or disease-free survival (neoadjuvant treatment vs. surgery-only: 84.9 vs. 88.2 %, p = 0.9; 76 vs. 79.1 %, p = 0.8).
Conclusions: The current study adds to the growing evidence that suggests a selective rather than generalized indication for neoadjuvant treatment in stages II and III rectal cancer.