Pathophysiology and therapy of irinotecan-induced delayed-onset diarrhea in patients with advanced colorectal cancer: a prospective assessment.

PURPOSE: Irinotecan (CPT-11), a camptothecin derivative, has shown efficacy against colorectal cancer. Delayed-onset diarrhea is its main limiting toxicity. The aim of this study was to determine the pathophysiology of CPT-11-induced delayed-onset diarrhea and assess the efficacy of combined antidiarrheal medication in a phase II, prospective, successive-cohorts, open study. PATIENTS AND METHODS: Twenty-eight patients with advanced colorectal cancer refractory to fluorouracil (5-FU) therapy received CPT-11 350 mg/m2 every 3 weeks. The first cohort of 14 consecutive patients explored for the mechanism of diarrhea received acetorphan (a new enkephalinase inhibitor) 100 mg three times daily; the second 14-patient cohort received, in addition to acetorphan, loperamide 4 mg three times daily. Before treatment, and if late diarrhea occurred, patients underwent colon mucosal biopsies for CPT-11 and topoisomerase I levels; intestinal transit time; fecalogram; fat and protein excretion; alpha1-antitrypsin clearance; D-xylose test; blood levels for vasoactive intestinal polypeptide, glucagon, gastrin, somatostatin, prostaglandin E2, and carboxylesterase; CPT-11/SN-38 and SN-38 glucuronide pharmacokinetics; and stool cultures. RESULTS: Delayed-onset diarrhea occurred during the first three treatment cycles in 23 patients (82%). Electrolyte fecal measurements showed a negative or small osmotic gap in nine of nine patients and an increased alpha1-antitrypsin clearance in six of six patients. There were no modifications in stool cultures or hormonal dysfunction. Four of 11 patients (36%) with delayed-onset diarrhea in the first cohort responded to acetorphan, whereas nine of 10 patients (90%) responded to the combination of acetorphan and loperamide (P < .02). CONCLUSION: CPT-11-induced delayed-onset diarrhea is caused by a secretory mechanism with an exudative component. Early combined treatment with loperamide and acetorphan seems effective in controlling the diarrheal episodes.

Long-term prognostic and predictive factors in 107 stage II/III breast cancer patients treated with anthracycline-based neoadjuvant chemotherapy.

The heterogeneity of therapeutic modalities and eligibility criteria and the lack of long-term follow-up in most reports of neoadjuvant chemotherapy for breast cancer preclude us from drawing conclusions about its value in clinically relevant patient subgroups. The present study aims to identify predictive and prognostic factors in 107 non-inflammatory stage II/III breast cancer patients treated between November 1980 and October 1991 with an anthracycline-based induction regimen before locoregional surgery. Preoperative chemotherapy comprised 3-6 cycles of doxorubicin (pirarubicin after 1986), vindesine, cyclophosphamide and 5-fluorouracil. Type of subsequent surgery and adjuvant treatment were decided individually. In analysis of outcome, univariate comparisons of end points were made using the log-rank test, and significant (P < or = 0.05) pre- and post-therapeutic factors were incorporated in a Cox multivariate analysis. With a median follow-up of 81 months (range 32-164+ months), the median disease-free survival (DFS) is 90.5 months while median overall survival has not yet been reached. Cytoprognostic grade and histopathological response in both the primary and lymph nodes were independent covariates associated with locoregional relapse with or without DFS and overall survival. Eleven patients with pathological complete response remain free of disease with a 68-month median follow-up, while the 18 with residual microscopic disease on the specimen showed a 60% cumulative incidence of locoregional recurrence. Despite encouraging response rates based on clinical or radiological evaluation (87% or 70%), neither method showed any significant correlation with pathological response and failed to contribute prognostic information on patients' outcome. Pathological evaluation of antitumoral activity of primary chemotherapy remains a major source of prognostic information and might be used to select patients in need of additional adjuvant treatment.