A retrospective, multicenter study of the efficacy of lapatinib plus trastuzumab in HER2-positive metastatic breast cancer patients previously treated with trastuzumab, lapatinib, or both: the Trastyvere study.

PURPOSE: To evaluate the efficacy and safety of lapatinib (L) and trastuzumab (T) combination in HER2-positive metastatic breast cancer (MBC) patients previously treated with T and/or L. MATERIALS AND METHODS: We conducted a retrospective, post-authorized, multicenter study including patients with HER2-positive MBC or locally advanced breast cancer (ABC) treated with the combination of L-T. Concomitant endocrine therapy, as well as brain metastasis and/or prior exposure to L, were allowed. RESULTS: One hundred and fifteen patients from 14 institutions were included. The median age was 59.8 years. The median number of prior T regimens in the advanced setting was 3 and 73 patients had received a prior L regimen. The clinical benefit rate (CBR) was 34.8% (95% CI 26.1-43.5). Among other efficacy endpoints, the overall response rate was 21.7%, and median progression-free survival (PFS) and overall survival were 3.9 and 21.6 months, respectively. Heavily pretreated and ≥ 3 metastatic organ patients showed lower CBR and PFS than patients with a low number of previous regimens and < 3 metastatic organs. Moreover, CBR did not significantly change in L-pretreated compared with L-naïve patients (31.5% versus 40.5% for L-pretreated versus L-naïve). Grade 3/4 adverse events were reported in 19 patients (16.5%). CONCLUSION: The combination of L-T is an effective and well-tolerated regimen in heavily pretreated patients and remains active among patients progressing on prior L-based therapy. Our study suggests that the L-T regimen is a safe and active chemotherapy-free option for MBC patients previously treated with T and/or L.

Update on adjuvant hormonal treatment of early breast cancer.

Clinical trials conducted over the last two decades have demonstrated that 5 years of treatment with tamoxifen (TAM) after local treatment in postmenopausal patients with positive hormone receptor early breast cancer improves disease-free survival and overall survival. More recently, aromatase inhibitors (AI) have been tested in several randomized clinical trials in this setting. The studies have tested either AI versus TAM or different sequential approaches combining the two agents. While the most effective strategy remains to be determined, overall, incorporation of AI resulted in better disease-free survival, particularly in the worst-prognosis subgroup of patients. In addition, long-term treatment with AI was, in general, well tolerated. However, mature results are needed in order to be able to assess the effect in overall survival. The authors of this supplement paper include the key points of roundtable presentations and discussions of hormonal therapy in breast cancer by topic.