Different cytotoxic chemotherapy regimens are associated with varying rates of hospitalization following their use in older women with stage IV breast cancer, according to a new study. The differences could help guide some treatment decisions in this setting.
“Elderly patients have been under-represented in clinical trials, and those who are included may be healthier than the general population of elderly patients,” wrote study authors led by Kenneth L. Kehl, MD, MPH, of the Dana-Farber Cancer Institute in Boston. “Understanding the benefits and risks of therapy in this population therefore requires a real-world assessment of adverse event patterns.”
The researchers conducted a retrospective analysis of patients aged 66–99 years in the SEER-Medicare database; it included a total of 693 patients who received a total of 972 lines of chemotherapy. The mean age at diagnosis was 74 years, and the median overall survival in the full cohort was 28.4 months. Results of the analysis were published in Cancer.
In total, 188 of the 972 lines of chemotherapy (19%) were associated with an inpatient hospitalization, skilled nursing facility stay, long-term care facility stay, or death within 30 days of the initiation of therapy. On a univariate analysis, there were no differences in the rate of this outcome between regimens, ranging from 14% for capecitabine to 33% for gemcitabine (P = .09).
The differences were significant, however, after adjustments for the number of prior lines of chemotherapy and for the time between initial diagnosis and initiation of the chemotherapy line in question (P = .01). Compared with capecitabine, the rate of 30-day hospitalization or death was higher among those receiving cyclophosphamide plus docetaxel, with an odds ratio (OR) of 2.71 (95% CI, 1.31–5.59); with docetaxel alone, with an OR of 2.49 (95% CI, 1.19–5.21); and with gemcitabine, with an OR of 3.51 (95% CI, 1.72–7.19).
A further sensitivity analysis that also adjusted for the number of prior inpatient stays within 60 days before therapy began did not significantly change the result. The authors noted that there could be unmeasured confounding with regard to the underlying severity of disease in these patients, in particular in those who received doublet chemotherapy.
“These patients suffer from a greater burden of comorbidity and frailty, and appropriate oncologic management requires considering both chronological age and functional status,” the authors wrote. “The results of our study may inform assessment of risk among patients considering a new line of palliative chemotherapy for breast cancer.”