Preoperative chemoradiation may not always be needed for patients with T3 and T2N+ rectal cancer

Preoperative chemoradiation is becoming the standard treatment for patients with locally advanced rectal cancer. However, since the introduction of total mesorectal excision (TME), local recurrence rates have been reduced significantly, and some patients can be spared from potentially toxic over treatment. The current study was designed to assess the factors that predict recurrence in an institutional series of patients with rectal cancer who had clinical T2 lymph node-positive (cT2N+) tumors or cT3N0/N+ tumors and underwent radical surgery without receiving preoperative chemoradiation.

Between November 1997 and November 2008, the authors' multidisciplinary group preoperatively staged 398 patients with rectal cancer by using endorectal ultrasonography and/or magnetic resonance imaging. The analysis included 152 consecutive patients with cT2N+, cT3N0, or cT3N+ rectal cancer who underwent TME without receiving preoperative chemoradiation. Macroscopic assessment of the mesorectal excision and circumferential resection margins were determined. Factors potentially related to local recurrence (LR), disease-free survival (DFS) and cancer-specific survival (CSS) were analyzed.

After a median follow-up of 39 months, the 5-year actuarial LR, DFS, and CSS rates were 9.5%, 65.4%, and 77.8%, respectively, for the whole group. Threatened mesorectal fascia at preoperative staging was the only independent preoperative factor that predicted a higher risk for LR (P = .007), shorter DFS (P = .007), and shorter CSS (P = .05). In particular, the 5-year LR rates for patients with and without preoperative threatened circumferential resection margins were 19.4% and 5.4%, respectively.

The current results suggested that patients with rectal cancer clinically staged as T3N0/N+ or T2N+ with a free margin >2 mm from mesorectal fascia may undergo TME alone, avoiding over treatment with preoperative chemoradiation.