Early increase in tamoxifen dose in CYP2D6 poor metaboliser breast cancer patients and survival: A propensity score matching analysis
Metadatos
Mostrar el registro completo del ítemAutor
Blancas López-Barajas, María Isabel; Linares Rodríguez, Marina; Molero Mir, Maria D.; Garrido, José M.; Rodríguez Serrano, FernandoEditorial
Elsevier
Materia
Breast cancer Tamoxifen CYP2D6 Disease free-survival Overall survival
Fecha
2023-03-23Referencia bibliográfica
I. Blancas et al.. Early increase in tamoxifen dose in CYP2D6 poor metaboliser breast cancer patients and survival: A propensity score matching analysis. The Breast 69 (2023) 342–348 .[https://doi.org/10.1016/j.breast.2023.03.012]
Patrocinador
Consejería de Salud y Familias-Junta de Andalucía (PECART-0207-2020); Fundación Hospital Provincial de Castell´on, Centre for Industrial Technological Development (CDTI, IDI 20080842)Resumen
Purpose: Tamoxifen is a drug used for hormone receptor-positive breast cancers, primarily metabolised by the
CYP2D6 enzyme into active metabolites such as endoxifen. CYP2D6 displays varying degrees of activity
depending on its genotype. This study aims to analyse the effect of an early increase in tamoxifen dose in poor
metabolisers (PM) on survival.
Methods: We enrolled 220 patients diagnosed with breast cancer who were treated with tamoxifen. CYP2D6
polymorphisms were determined, and the phenotype was estimated according to the Clinical Pharmacogenetics
Implementation Consortium. Disease-free survival (DFS) and overall survival (OS) were analysed considering the
entire patient group, and a subgroup of 110 patients selected by Propensity Score Matching (PSM). All women
were treated with 20 mg/day of tamoxifen for 5 years, except PM, who initially received 20 mg/day for 4
months, followed by 40 mg/day for 4 months and 60 mg/day for 4 months before returning to the standard dose
of 20 mg/day until completing 5 years of treatment.
Results: The analysis of the influence of CYP2D6 polymorphisms in the complete group and in the PSM subgroup
revealed no significant differences for DFS or OS. Furthermore, DFS and OS were analysed in relation to various
covariates such as age, histological grade, nodal status, tumour size, HER-2, Ki-67, chemotherapy, and radiotherapy.
Only age, histological grade, nodal status, and chemotherapy treatment demonstrated statistical
significance.
Conclusion: An early increase in tamoxifen dose in PM patients is not associated with survival differences among
CYP2D6 phenotypes.