Relative dose intensity of taxane-based chemotherapy in breast cancer patients in a tertiary hospital

Abstract

Introduction Breast cancer (BC) is the most diagnosed tumor among women worldwide. The aim of this study was to investigate the incidence and causes of low relative dose intensity (RDI) < 85% for taxane-based chemotherapy regimens used in the treatment of BC in Sultan Qaboos University Hospital (SQUH). Methods This was a retrospective study that included 303 BC patients, treated with taxane-based chemotherapy protocols at SQUH. RDI was calculated for each chemotherapy regimen and causes and predictors of low RDI < 85% were identified. Prophylactic and therapeutic supportive measures for certain toxicities were studied. Results 50.8% of the patients had neoadjuvant chemotherapy, 38% had adjuvant chemotherapy, and 11.2% of patients were given palliative treatment. AC-T and AC-THP were the most used regimens (40.3% and 17.2%). Mean RDI of used taxane-based chemotherapy regimens was 93.4%. Dose delays, dose reductions, and treatment discontinuation occurred in 36.6%, 14.8%, and 11.5%, respectively. Thirty-eight patients (12.5%) had low RDI < 85% which was reduced to 9.9% after the use of an alternative taxane. Age and chemotherapy intent were significant risk factors. 83.8% received primary granulocyte colony stimulating factor. Conclusion An optimal RDI greater than 85% was achieved in most cases. Furthermore, prophylactic and therapeutic supportive measures were widely used.