Phase II study of irinotecan in the treatment of advanced colorectal cancer in chemotherapy-naive patients and patients pretreated with fluorouracil-based chemotherapy.

PURPOSE: To assess the efficacy of irinotecan (CPT-11) in the treatment of advanced colorectal cancer in both chemotherapy-naive and pretreated patients. PATIENTS AND METHODS: Two hundred thirteen patients (aged 18 to 75 years) with metastatic colorectal cancer, World Health Organization (WHO) performance status < or = 2, and life expectancy > or = 3 months were treated with CPT-11 350 mg/m2 every 3 weeks. All 178 patients eligible for efficacy analysis had not received more than one prior fluorouracil (5-FU)-based chemotherapy regimen (adjuvant or palliative) and had adequate hematologic, renal, and hepatic function. RESULTS: Primary tumor sites were the colon (71%) and rectum (28%). Sixty-six percent of the patients had > or = two metastatic sites. Ninety-eight percent of the patients had undergone previous surgery, and 77.5% had received prior chemotherapy. Thirty-two of 178 eligible patients achieved on objective response (four complete responses [CRs] and 28 partial responses [PRs]; response rate, 18%; 95% confidence interval, 12.6% to 24.4%), 65 were stable, and 59 progressed. The response rate was 17.7% in the pretreated group and 18.8% in the chemotherapy-naive group. Within the former subgroup, response rates of 16.1% were reported in patients who were progressive on prior 5-FU chemotherapy and 19.1% in patients who were progressive off such treatment. The median duration of objective response (9.1 months) and median time to achievement of a response (9.3 weeks) did not differ between chemotherapy-naive and pretreated patients. The most frequent adverse events were neutropenia, which developed in 80% of the patients, delayed diarrhea (87%), alopecia (88%), fatigue (81%), and nausea/vomiting (77%). All these adverse events were manageable. Severe (WHO grade 3 or 4) neutropenia was only observed in 18% of the cycles, leukopenia in 11%, delayed diarrhea in 11%, and nausea and vomiting in 3%. Development of simultaneous grade 3 or 4 neutropenia and delayed diarrhea during 4% of the cycles was the safety issue of greatest concern. CONCLUSION: CPT-11 has definite activity in the treatment of advanced metastatic colorectal cancer both in chemotherapy-naive and in pretreated patients who experienced disease progression on 5-FU, which suggests a lack of cross-resistance between CPT-11 and 5-FU. Diarrhea and neutropenia, the major toxicities of CPT-11, contribute to the risk to develop febrile neutropenic sepsis.

Kinetics of methotrexate and its metabolites in red blood cells.

It has been suggested that the intra-erythrocyte levels of methotrexate (MTX) and its polyglutamized derivatives could offer a method for evaluating intracellular MTX accumulation and its metabolism in children with acute lymphoblastic leukemia. We were interested in measuring the intra-erythrocyte levels of MTX in patients with solid tumors receiving high-dose MTX treatment. After a first incorporation stage occurring during infusion, MTX concentrations subsequently increased 9-12 days after the treatment as polyglutamized derivatives. Thirty days after the infusion, MTX and its polyglutamates were still measurable in erythrocytes. The percentage of polyglutamization varied on an individual basis, but two groups of patients could be separated according to their ability to form polyglutamates. We also noted the presence of 7-hydroxy-methotrexate (7-OH-MTX) appearing 48 hours after the beginning of the infusion which was still present in 17/20 samples 30 days after the treatment.