Survival outcome is similar for first-line chemotherapy with capecitabine or taxane for metastatic breast cancer.

Abstract

Abstract Abstract #6091 Background: Capecitabine is often offered as first-line treatment option for metastatic breast cancer (MBC). In this study, we compare characteristics of and survival among women prescribed capecitabine or taxane monotherapy as first-line chemotherapy for MBC.
 Methods: Women receiving first-line chemotherapy for MBC from 1998 to 2005 were identified from the North Carolina tumor registry linked with Medicaid and Medicare claims records, and were followed through the end of 2005 with survival data from the National Death Index. T-tests and Chi-square tests were used to compare baseline charactistics between patients who received first-line chemotherapy with capecitabine versus taxane (paclitaxel or docetaxel). Overall survival was examined as average months survived post-diagnosis of metastases using Cox proportional hazard modeling. The following variables were included in the models: age, race, comorbidity, insurance coverage, hormone receptor (HR) status, time from diagnosis of metastases to first-line chemotherapy, trastuzumab use, time from initial diagnosis to metastasis, receipt of adjuvant chemotherapy or hormonal therapy, and year of first-line chemotherapy.
 Results: There were 257 patients with MBC starting first-line chemotherapy with capecitabine (n=71) or a taxane (n=186). Statistically significant differences between patients treated with capecitabine versus taxane were seen for the following baseline characteristics: insurance coverage, such that women in the taxane group were more likely insured by Medicare only; time from initial diagnosis to recurrence was longer in the capecitabine group; time from metastases to first-line chemotherapy was longer in the capecitabine group. The unadjusted 1-year overall and cancer-specific survival rates were longer for the taxane treated group than for the capecitabine treated group: 72% vs 59%, p=0.002, and 75% and 63%, p=0.01. In multivariate analysis, treatment received was not associated with overall or cancer-specific survival after adjustment for baseline differences in the populations. Factors significantly associated with increased overall and cancer-specific survival were positive HR status (HR 0.65, p=0.01; HR 0.60, p=0.005), greater time from metastases until 1st line chemotherapy (for each additional month: HR 0.95, p 0.0001; HR 0.96, p=0.0004), and earlier year of 1st line chemotherapy (for each previous year compared to successive year 2005-1998: HR 0.86, p=0.022; HR 0.86, p=0.03).
 Conclusions: In this population-based study, women who received capecitabine as first-line treatment for MBC were more often insured by Medicaid, had a longer disease free interval and time to first-line chemotherapy from diagnosis of metastases. In multivariate analysis, however, first-line capecitabine and taxane for MBC yielded similar survival outcomes. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6091.