Chemotherapy-induced neutropenia as a prognostic factor in patients with extensive-stage small cell lung cancer.

PURPOSE: Chemotherapy-induced neutropenia (CIN) is a dose-limiting factor for cytotoxic chemotherapy, but recently, it was suggested that CIN contributes to prolonged survival. In this study, we examined the association between severe CIN and survival and determined whether CIN affected survival in patients with extensive-stage small cell lung cancer (ES-SCLC). METHODS: The medical records from 214 patients with ES-SCLC treated with etoposide or irinotecan in combination with cisplatin (EP/IP) between 2012 and 2016 were collected and retrospectively analyzed. Landmark analysis was performed at the end of cycle 4, and the relationship between severe CIN and survival was determined by a log-rank test. In addition, a multivariate analysis using the COX proportional hazard model was performed to identify independent predictive factors. The Landmark analysis included 102 patients in the IP group and 47 patients in the EP group. RESULTS: No significant difference was found between grades 0-3 and grade 4 neutropenia and overall survival (OS) in the EP group (P = 0.57). Contrariwise, for the IP patients, the median OS was 444 days for grades 0-3 and 633 days for grade 4 neutropenia, which was significantly longer for patients who developed grade 4 neutropenia (P = 0.03). Multivariate analysis adjusted for potential factors revealed that the development of grade 4 CIN was identified as a significant predictor of longer OS (hazard ratio [HR], 0.50; 95% confidence interval (CI), 0.28-0.87, P = 0.015). CONCLUSION: The results indicated that the development of severe CIN with IP therapy is associated with prolonged OS.

Genetic risk factors for chemotherapy-induced nausea and vomiting in patients with cancer receiving cisplatin-based chemotherapy.

PURPOSE: Younger age and female sex have already been well-known risk factors for chemotherapy-induced nausea and vomiting (CINV), and 30-50% of cancer patients still suffer from CINV. Genetic polymorphisms are suggested to influence antiemetic treatment response. METHODS: This study included a subset of patients previously enrolled in a randomised controlled trial; 156 patients were evaluated. This study aimed to evaluate the role of pharmacogenomic polymorphisms relevant to antiemetic response in patients with cancer receiving cisplatin-based chemotherapy. The study's efficacy endpoint was the proportion of patients with complete response (CR). The study endpoint was evaluated separately in the acute (CR0-24) and delayed (CR24-120) phases. Thirteen polymorphisms were genotyped, and the association of these genotypes with the efficacy of prophylactic antiemetics was then investigated. Confounding variables for the CR were identified using stepwise multivariate logistic regression analysis. Age and sex were included as independent variables by the forced-entry method, and the stepwise method was used to select the pharmacogenomic factors for inclusion as independent variables. RESULTS: Multivariate logistic regression analysis revealed that the ERCC1 8092AA (odds ratio [OR] = 11.25; 95% confidence interval [CI] 1.74-72.71; p = 0.011) and female sex (OR = 3.63; 95% CI 1.14-11.58; p = 0.029) were significant predictors of CR0-24. No significant association of CR24-120 with pharmacogenomic polymorphisms was found via multivariate logistic regression analysis. CONCLUSIONS: ERCC1 polymorphism influenced the extent of CINV control in patients receiving cisplatin-based chemotherapy. TRIAL REGISTRATION: Clinical trial information: UMIN 000009335.

Receptor occupancy theory-based analysis of interindividual differences in antiemetic effects of 5-HT3 receptor antagonists.

BACKGROUND: The aim of this study was to estimate interindividual differences in the antiemetic effects of 5-HT(3) receptor antagonists by evaluating the influence of pharmacokinetics on 5-HT(3) receptor occupancies, based on receptor occupancy theory. METHODS: We analyzed interindividual differences of 5-HT(3) receptor occupancies and antiemetic effects after the oral and/or intravenous administration of standard doses of the following 5-HT(3) receptor antagonists: azasetron, granisetron, indisetron, ondansetron, ramosetron, and tropisetron. RESULTS: The interindividual difference between maximum and minimum 5-HT(3) receptor occupancies after oral administration ranged from 0.6% to 64.0%, and that difference after intravenous administration ranged from 0.6% to 29.6%. Following oral administration, the interindividual difference between maximum and minimum complete vomiting inhibition rates ranged from 0.2% to 16.1%. After intravenous administration, that difference ranged from 0.8% to 52.5%. CONCLUSION: Interindividual differences in the clinical effects of 5-HT(3) receptor antagonists could be evaluated based on receptor occupancy theory, and the differences varied among drugs. Drug selection considering these individual variations might be useful for the patients who experienced vomiting associated with chemotherapy.