Gemcitabine single or combination chemotherapy in post anthracycline and taxane salvage treatment of metastatic breast cancer: retrospective analysis of 124 patients

Purpose: To evaluate the efficacy of gemcitabine-based chemotherapy, particularly in patients with anthracycline- and taxane-pretreated 2(nd)-line or greater metastatic breast cancer, and to compare gemcitabine monotherapy (G) with two gemcitabine-based doublets, gemcitabine/vinorelbine (GV) and gemcitabine/capecitabine (GX).

Materials and methods: Of 124 consecutive patients who progressed after anthracycline- and taxane-containing chemotherapy, 58 received G alone, 38 received GV, and 28 received GX; their outcomes were analyzed retrospectively.

Results: The median number of prior metastatic chemotherapy regimens was 2 (range 0 approximately 4). Visceral metastases were observed in 65 patients (51.4%). The overall response rate was 19.3% (21 partial responses). After a median follow-up period of 21.4 months, the overall survival was 7.6 months (95% CI: 5.5 approximately 9.6 months) and the median time to progression was 3.1 months (95% CI: 2.0 approximately 4.2 months). Compared with monotherapy (G), combination therapy with vinorelbine or capecitabine (GV/GX) was associated with a significantly higher response rate (8.2% vs. 28.3%, p=0.008) and a significantly longer median time to progression (2.8 vs. 3.5 months; p=0.028), but overall survival did not differ between the groups (7.4 vs. 8.2 months, respectively; p=0.54). Most of the adverse treatment-related events were mild to moderate in intensity. The most common adverse event was hematologic toxicity. Multivariate analysis showed that poor performance status and a short disease-free interval were independent prognostic factors for impaired overall survival.

Conclusions: The combination of gemcitabine with vinorelbine or capecitabine was an active and well-tolerated treatment option for taxane- and anthracycline-pretreated 2(nd)-line or greater metastatic breast cancer patients, and gemcitabine-based doublets were more beneficial than gemcitabine monotherapy in alleviating symptoms for these patients.