Clinically-staged T3N0 rectal cancer: is preoperative chemoradiotherapy the optimal treatment?

Preoperative chemoradiotherapy has been widely adopted as the standard of care for stage II-III rectal cancers. However, patients with T3N0 lesions had been shown to have a better prognosis than other categories of locally advanced tumor. Thus, neoadjuvant chemoradiation is likely to be overtreatment in this subgroup of patients. Nevertheless, the low accuracy rate of preoperative staging techniques for detection of node-negative tumors does not allow to check this hypothesis. We analyzed a group of patients with cT3N0 low rectal cancer who underwent neoadjuvant chemoradiotherapy with the purpose of evaluating the incidence of metastatic nodes in the resected specimens.

Between January 2002 and February 2008, 100 patients with low rectal cancer underwent clinical staging by means of endorectal ultrasound, computed tomography, positron emission tomography, and magnetic resonance imaging. All patients received preoperative 5-fluorouracil-based chemoradiotherapy and surgical resection with curative aim.

Of 100 patients with locally advanced rectal cancer, 32 were clinically staged as T3N0M0. Pathological analysis showed the presence of lymph node metastases in nine patients (28%) (node-positive group). In the remaining 23 cases, clinical N stage was confirmed at pathology (node-negative group). Node-positive and node-negative groups differ only in the number of ypT3 tumors (P < .01).

Our results indicate that immediate surgery for patients with cT3N0 rectal cancer represents an undertreatment risk in at least 28% of cases, making necessary the use of postoperative chemoradiotherapy. Preoperative chemoradiotherapy should be the therapy of choice on the grounds of the principle that overtreatment is less hazardous than undertreatment for cT3N0 rectal cancers.