Breast Cancer Treatment (PDQ®): Treatment - Health Professional Information [NCI] - Stage IIIB, Inoperable IIIC, IV, Recurrent, and Metastatic Breast Cancer
Further evidence of T-DM1's activity in metastatic HER2-overexpressed breast cancer was shown in a randomized phase II study of T-DM1 versus trastuzumab plus docetaxel.[Level of evidence: 1iiDiii] This trial randomly assigned 137 women with HER2-overexpressed breast cancer in the first-line metastatic setting. At median follow-up of 14 months, median PFS was 9.2 months with trastuzumab plus docetaxel and 14.2 months with T-DM1 (HR, 0.59; 95% CI, 0.36–0.97). T-DM1 had a favorable safety profile compared with trastuzumab plus docetaxel, with fewer grade 3 AE, (46.4% vs. 90.9%), AE leading to treatment discontinuations (7.2% vs. 40.9%), and serious AE (20.3% vs. 25.8%). Preliminary OS results were similar between treatment arms.
Patients whose tumors have progressed on hormone therapy are candidates for cytotoxic chemotherapy. Patients with hormone receptor–negative tumors and those with visceral metastases are also candidates for cytotoxic agents.
Single agents that have shown activity in metastatic breast cancer include the following:
- Liposomal doxorubicin.[65,66,67,68]
- Albumin-bound nanoparticle paclitaxel (ABI-007 or Abraxane).[71,72]
- Alkylating agents.
- Vinca alkaloids.
- Mitomycin C.
- Eribulin mesylate.[78,79]
Combination regimens that have shown activity in metastatic breast cancer:
- CA: cyclophosphamide and doxorubicin.
- Docetaxel and doxorubicin.
- CAF: cyclophosphamide, doxorubicin, 5-fluorouracil.
- CMF: cyclophosphamide, methotrexate, 5-fluorouracil.
- Doxorubicin and paclitaxel.[84,85]
- Docetaxel and capecitabine.
- Vinorelbine and epirubicin.
- Capecitabine and ixabepilone.
Whether single-agent chemotherapy or combination chemotherapy is preferable for first-line treatment is unclear. An Eastern Cooperative Oncology Intergroup study (E-1193) randomly assigned patients to receive paclitaxel and doxorubicin given both as a combination and sequentially. Although response rate and time-to-progression were both better for the combination, survival was the same in both groups.[Level of evidence: 1iiA];[90,91] The rate of disease progression, the presence or absence of comorbid medical conditions, and physician/patient preference will influence the choice of therapy in individual patients. At this time, no data support the superiority of any particular regimen. Sequential use of single agents or combinations can be used for patients who relapse. Combinations of chemotherapy and hormone therapy have not shown an OS advantage over the sequential use of these agents.[15,92] A systematic review of 17 randomized trials found that the addition of one or more chemotherapy drugs to a chemotherapy regimen in the attempt to intensify the treatment improved tumor response but had no effect on OS.[Level of evidence: 1iiA]