Postoperative chemotherapy may not be necessary for patients with ypN0-category after neoadjuvant chemoradiotherapy of rectal cancer

PURPOSE: After neoadjuvant radiochemotherapy and surgery, there is no general agreement about whether postoperative chemotherapy is necessary. With the help of clinical and pathohistologic data, prognostic factors were determined as a basis for the decision to spare a patient additional chemotherapy or to urgently recommend it. RESULTS: Ninety-five patients treated with neoadjuvant 5-fluorouracil-based radiochemotherapy (November 4, 1997 and June 15, 2004) without distant metastases and an R0 (microscopically complete) resection were evaluated. Adjuvant chemotherapy (5-fluorouracil or 5-fluorouracil/folinic acid) was given to 65 of 95 patients (68.4 percent). The disease-free survival rate after 36 months was chosen as the target parameter (median follow-up, 36 months). METHODS: The five-year survival rate for all patients was 80.3 +/- 5.6 percent; the five-year disease-free survival was 78.1 +/- 5.1 percent; the five-year local control rate was 94.2 +/- 5.1 percent. In the univariate and multivariate analysis of the disease-free survival, the pathohistologic lymph node status after radiochemotherapy (ypN) was the only significant prognostic parameter. Disease-free survival (36 months) for patients without lymph node metastases (ypN0) was excellent, independent of whether they had received postoperative chemotherapy (n = 43; 87.5 +/- 6.0 percent) or not (n = 29; 87.7 +/- 6.7 percent). Patients with ypN2 status have, despite chemotherapy, a poor disease-free survival at 30 +/- 17.6 percent after 36 months. CONCLUSIONS: These retrospective data suggest that, for some patients, postoperative chemotherapy can be spared. For patients with ypN2 status, an intensification of the postoperative chemotherapy should be considered. Further evaluation in prospective studies is urgently recommended.