ABSTRACT
Chemotherapy-induced neutropenia (CIN) is one of the major adverse events that necessitate chemotherapy dose reduction. This study aimed to evaluate the association between grade 4 neutropenia and genetic polymorphisms in breast cancer patients. In this genetic polymorphism association study, peripheral blood samples from 100 consecutive breast cancer outpatients, between August 2012 and September 2014, treated with doxorubicin and cyclophosphamide (AC) combination chemotherapy were genotyped for polymorphisms in adenosine triphosphate-binding cassette subfamily B member 1 (ABCB1), cytochrome P450 (CYP) enzyme-coding genes (CYP2B6 and CYP3A5), glutathione S-transferase (GST), and excision repair cross-complementing 1 (ERCC1). Associations between grade 4 neutropenia and genotypes as well as risk factors were examined using multivariate logistic regression. From 100 patients, 32.0% had grade 4 neutropenia. Multivariate logistic regression analysis revealed that ERCC1 118Câ>âT (odds ratio [OR], 3.43; 95% confidence interval [CI], 1.22-9.69; Pâ=â0.020), CYP2B6*6 (OR, 4.51; 95% CI, 1.21-16.95; Pâ=â0.025), body mass index (BMI) (OR, 6.94; 95% CI, 1.15-41.67; Pâ=â0.035), and baseline white blood cell (WBC) count (OR, 2.99; 95% CI, 1.06-8.40; Pâ=â0.038) were significant predictors of grade 4 neutropenia. ERCC1 and CYP2B6 gene polymorphisms were associated with the extent of grade 4 neutropenia in patients receiving AC chemotherapy. In addition to previously known risk factors, BMI and WBC counts, ERCC1 and CYP2B6 gene polymorphisms were also identified as independent strong predictors of grade 4 neutropenia.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/adverse effects , Breast Neoplasms/drug therapy , Breast Neoplasms/genetics , Neutropenia/chemically induced , Polymorphism, Genetic , Female , Hospitalization , Humans , Middle Aged , Severity of Illness IndexABSTRACT
Chemotherapy-induced neutropenia is one of the major adverse events which results in the reduction of chemotherapy. Doxorubicin is a substrate of the adenosine triphosphate-binding cassette subfamily B member 1 (ABCB1) transporter; reportedly, ABCB1 polymorphisms influence doxorubicin pharmacokinetics. We evaluated the association between chemotherapy-induced neutropenia and ABCB1 polymorphisms in patients with breast cancer. We investigated 141 patients with breast cancer treated with doxorubicin and cyclophosphamide (AC) chemotherapy. Peripheral blood samples obtained from patients were genotyped for the ABCB1 2677G>T/A and 3435C>T polymorphisms. The genotypes were then investigated for their association with grade 3 or greater neutropenia, and further their risk factors were examined using a multivariate logistic regression. The proportion of patients with grade 3 or greater neutropenia was 85.7% in the homozygous variant group, and 80% and 58.6% in the heterozygous variant and GG genotype groups, respectively (p = 0.021). The multivariate logistic regression analysis revealed that the ABCB1 2677G>T/A polymorphism was a strong predictor of grade 3 or greater neutropenia (odds ratio: 3.76; 95% confidence interval: 1.44-9.81; p = 0.007). ABCB1 polymorphisms may influence the extent of chemotherapy-induced neutropenia in AC combination-treated patients with breast cancer.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/adverse effects , Breast Neoplasms/drug therapy , Cyclophosphamide/adverse effects , Doxorubicin/adverse effects , Neutropenia/chemically induced , Neutropenia/genetics , Polymorphism, Single Nucleotide , ATP Binding Cassette Transporter, Subfamily B/genetics , Adult , Chi-Square Distribution , Female , Gene Frequency , Genetic Predisposition to Disease , Heterozygote , Homozygote , Humans , Logistic Models , Middle Aged , Multivariate Analysis , Neutropenia/diagnosis , Odds Ratio , Phenotype , Retrospective Studies , Risk Factors , Severity of Illness IndexABSTRACT
BACKGROUND: Neutropenia is one of the most important dose-limiting toxicities of docetaxel. Docetaxel is metabolized by cytochrome P450 3A4 (CYP3A4). Clarithromycin, a potent inhibitor of CYP3A4, is occasionally used in combination with docetaxel. The aim of this study was to evaluate whether the risk of severe neutropenia induced by docetaxel was increased by concomitant administration of clarithromycin. METHODS: Patients with advanced lung cancer receiving docetaxel were identified from an electronic medical record system and divided into 2 groups: concomitant administration of clarithromycin and no concomitant administration of clarithromycin. The proportion of patients experiencing grade 4 neutropenia between the 2 groups was compared. Potential risk factors associated with grade 4 neutropenia were also examined using univariate and multivariate logistic regression analyses. RESULTS: One hundred and fifty-eight patients were analysed. Grade 4 neutropenia was more frequently detected in the patients receiving clarithromycin than in those not receiving the drug (63.2 vs. 35.3%; p = 0.025). Multivariate analysis showed that co-administration of clarithromycin [odds ratio (OR) 4.98; p = 0.004], pre-treatment absolute neutrophil count (OR 2.62; p = 0.011) and female gender (OR 2.75; p = 0.029) resulted in an increase in the incidence of grade 4 neutropenia. CONCLUSIONS: This study shows that concomitant administration of clarithromycin potentiated docetaxel-induced myelosuppression.
