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.

Analysis of pharmacogenomic factors for chemotherapy-induced nausea and vomiting in patients with breast cancer receiving doxorubicin and cyclophosphamide chemotherapy.

PURPOSE: Chemotherapy-induced nausea and vomiting (CINV) can lead to a significant deterioration in the quality of life of cancer patients receiving chemotherapy. This study aimed to determine whether ABCB1 2677G > T/A was associated with complete response (CR; defined as no vomiting and no rescue medication) in acute phase (CR0-24), as well as to explore the genetic factors affecting delayed phase (CR24-120) CINV in cancer patients treated with a standard triple antiemetic regimen that included aprepitant. METHODS: This prospective single-center study included a total of 166 chemotherapy-naïve patients with breast cancer who received a standard dose of doxorubicin and cyclophosphamide combination chemotherapy; granisetron, dexamethasone, and aprepitant were administered prior to chemotherapy. CR0-24 was compared between minor allele homozygous (TT, AA, and TA) and major allele homozygous plus heterozygous (GG, GA, and GT) groups of ABCB1 2677G > T/A. In addition, 14 genetic polymorphisms were genotyped and their associations with CRs were investigated. RESULTS: The proportion of patients who achieved CR0-24, which was the primary endpoint of this study, was 59% in the minor allele homozygous and 61% in the major allele homozygous plus heterozygous groups of ABCB1 2677G > T/A. Although this difference was not statistically significant, multivariate logistic regression analysis adjusted for potential risk factors showed that TACR1 1323TT (OR, 2.57; P = 0.014) was a significant determinant of CR24-120. CONCLUSION: No significant association was found between ABCB1 2677G > T/A and CR0-24. However, it was observed that the polymorphism of TACR1, which encodes the neurokinin 1 receptor, might be a potential genetic risk factor for the development of delayed phase CINV.