First-line treatment with irinotecan and raltitrexed in metastatic colorectal cancer. Mature results of a multicenter phase II study.

OBJECTIVES: The combination of irinotecan and raltitrexed is safe and active in 5-fluorouracil-refractory, metastatic colorectal cancer (CRC), with the advantage of its convenient three-weekly schedule. The aim of this multicenter phase II study was to assess its efficacy and toxicity in first-line treatment. METHODS: Between May 2000 and March 2001, 62 previously untreated patients received irinotecan (350 mg/m(2)) plus raltitrexed (3 mg/m(2)), with courses repeated every 21 days. Objective response was assessed every three courses, and treatment maintained until tumor progression or unacceptable toxicity. RESULTS: A total of 331 cycles were administered, with a median of five cycles per patient (range, 1-16). Seventeen patients achieved a partial response and 2 a complete response, for an overall intention-to-treat response rate of 30% (95% confidence interval, 18-44%). The incidence of grade 3-4 toxicity per patient was diarrhea (27%), emesis (13%), anemia (12%), neutropenia (9%), and asthenia (7%). Three patients (5%) died from treatment-related adverse events (diarrhea plus neutropenia). The median potential follow-up is now 37 months. Median survival was 12.2 months, and median time to progression was 6.3 months. CONCLUSIONS: The combination of irinotecan plus raltitrexed is an easy comfortable schedule for patients with metastatic CRC, but both efficacy and toxicity results seem suboptimal for first-line treatment.

Preoperative uracil, tegafur, and concomitant radiotherapy in operable rectal cancer: a phase II multicenter study with 3 years' follow-Up.

PURPOSE: To assess tolerance and efficacy of preoperative treatment with uracil/tegafur and radiotherapy (RT) followed by surgery and postoperative flurouracil (FU)/leucovorin (LV) in patients with rectal cancer. PATIENTS AND METHODS: Patients (n = 94) with potentially resectable tumors, ultrasound at stages T2N+ (n = 4), T3 (n = 77), T4 (n = 13) were treated with UFT (400 mg/m2/d, 5 days a week for 5 weeks) and concomitant RT to the pelvis (45 Gy; 1.8 Gy/d over 5 weeks). Patients underwent surgery 5 to 6 weeks later followed by four cycles of FU/LV. Primary end points included downstaging, pathologic responses, and sphincter-preserving surgery. Secondary end points were recurrence-free survival and overall survival. RESULTS: All patients received the full RT dose. Fifteen patients (16%) needed UFT dose reduction. Preoperative G3+ toxicities included diarrhea (14%), leukopenia (1%), thrombocytopenia (1%), and nausea (4%). The downstaging rate was 54%, pathologic complete response (pCR) was 9% and, in an additional 23%, there were only residual microscopic foci. When cellular viability criteria were taken into account, the pCR was 15%. From 43 patients with abdominoperineal resection indication, 11 (25%) had sphincter-preserving surgery performed. Postoperative scheduled chemotherapy dose was not administered to 24% of patients because of G3+ toxicity (diarrhea, 8%; mucositis, 9%; and leukopenia, 7%). Patients with downstaging had significantly higher survival and recurrence-free survival rates than those without. At 3 years, actuarial patterns of failure were pelvic, 5% and distant, 11%. OS was 75%. CONCLUSION: UFT combined with RT is safe and effective. In resectable rectal cancer, if preoperative treatment is considered, this approach can be an option.

Multicenter phase I study of irinotecan plus raltitrexed in patients with 5-fluorouracil-refractory advanced colorectal cancer.

Irinotecan and raltitrexed are active against advanced colorectal cancer, act through different mechanisms, and have non-overlapping toxicity profiles. In vitro studies have shown a schedule-dependent synergism between both drugs. The aim of this multicenter study was to determine the maximum tolerated dose (MTD) of this combination. Patients with 5-fluorouracil-refractory, advanced colorectal cancer were eligible. Dose escalation consisted of irinotecan (250-350 mg/m(2) as a 60-min infusion) in combination with a fixed dose of raltitrexed (3 mg/m(2) as a 15-min infusion, 1 h after irinotecan). Courses were repeated every 21 days. Three to 6 patients were to be included at each dose level. Dose limiting (NCI-CTC grade 3-4) toxicities (DLT) were assessed during the first 2 cycles. Thirteen patients were recruited (4, 3 and 6 in levels I, II and III, respectively). Main toxicity was diarrhea and asthenia, whereas myelotoxicity was mild. At level III, 2/6 patients experienced DLT (grade 4 diarrhea and neutropenia). The MTD was not reached, but further dose escalation was not attempted. Among 12 patients with measurable disease, 2 partial responses were observed for an overall response rate of 17%. The combination of single-agent full doses of irinotecan (350 mg/m(2)) and raltitrexed (3 mg/m(2)) in a 3-weekly schedule is feasible, with mild toxicity and a promising clinical activity. Diarrhea is the DLT, but it is not more common or severe than that described with irinotecan alone.