Feasibility and toxicity of dose-dense adjuvant chemotherapy in older women with breast cancer

Introduction The objective of this study was to examine the feasibility and toxicity of adjuvant dose-dense chemotherapy in older women with breast cancer. Methods A search of the Memorial Sloan-Kettering Cancer Center (MSKCC) breast cancer database was performed to identify all patients age 60 and older who underwent an initial consultation with a breast medical oncologist between October 1, 2002 and June 28, 2005. Inclusion criteria were: (1) age ≥ 60, (2) follow-up care obtained at MSKCC, (3) intent to treat with adjuvant dose-dense AC-T (doxorubicin 60 mg/m² and cyclophosphamide 600 mg/m² every 2 weeks for 4 cycles followed by paclitaxel 175 mg/m² every 2 weeks for 4 cycles, with white blood cell growth factor support). Results One hundred sixty-two patients (mean age 66, range 60–76) with breast cancer, stages I (n = 5), II (n = 111), and III (n = 46) according to the sixth edition of the AJCC staging system, were included in this analysis. Forty-one percent (n = 67) experienced a grade 3 or 4 toxicity, 9% a grade 3 infection (n = 14), 6% grade 3 fatigue (n = 9), 5% neutropenic fever (n = 8), and 4% thromboembolic events (n = 7). Twenty-two percent (n = 36) did not complete the planned 8 cycles of treatment. There was no statistically significant association between age and either toxicity or treatment discontinuation. In multivariate analysis including age, pretreatment hemoglobin, and comorbidity, the presence of comorbidity (Charlson score ≥ 1) and a lower baseline hemoglobin score were associated with an increased risk of any grade 3 or 4 toxicity. Conclusions We found that the risk of toxicity depended more on comorbid medical conditions and baseline hemoglobin value than age in this cohort of older adults receiving dose-dense adjuvant chemotherapy.