Intensified irinotecan-based neoadjuvant chemoradiotherapy in rectal cancer: four consecutive designed studies to minimize acute toxicity and to optimize efficacy measured by pathologic complete response.

BACKGROUND: The objective of the present study was to analyse toxicity and efficacy of irinotecan-based neoadjuvant chemoradiotherapy by the help of four consecutively planed and prospectively performed phase II studies. PATIENTS AND METHODS: Patients with locally advanced rectal cancer received radiotherapy and concurrently chemotherapy consisting 5-Fu/capecitabine in a continuous or intermittent application and irinotecan in two different total doses (240 vs. 200 mg/m(2)). RESULTS: Diarrhea CTC grade III was seen in 35% in continuous application of 5-Fu/capecitabine versus 12.5% in intermittent application (p= 0,008). Complete response according to the irinotecan dose during chemoradiotherapy (240 mg/m(2) vs. 200 mg/m(2)) was 24% and 0%. CONCLUSIONS: Chemoradiotherapy of the last phase II study with intermittent capecitabine (1500 mg/m(2)/day, delivered on days 1-14 and 22-35) and irinotecan (4 x 60 mg/m(2)) concurrently to radiotherapy is a safe treatment with low toxicity and high efficacy.

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.