Combination chemotherapy in HER2-positive breast cancer

This study investigated adjuvant (after surgery) chemotherapy in HER2-positive breast cancer (BC). They found that survival rates were similar across chemotherapy regimens. 

Breast cancer (BC) is a very common and treatable form of cancer. Survival rates in BC have been improved by targeted therapies. These involve medications that target cancer cells based on the proteins they express on the surface. One type of BC is HER2-positive (HER2+). In this type of cancer, cancer cells express a HER2 protein. Trastuzumab (Herceptin) is a targeted therapy for HER2+ BC. 

Surgery is usually the first step in BC treatment. Adjuvant chemotherapy (ACT) is administered after BC surgery. Cancer cells can easily travel to the lymph nodes in patients with BC. ACT helps kill any cancer cells that were not surgically removed. Combining trastuzumab with ACT has been very effective in HER2+ patients with and without cancer cells in the nodes. It is unclear if a certain type of ACT (in combination with trastuzumab) is more effective in HER2+ BC.

This study included 1006 women with HER2+ BC. There were 3 ACT regimens evaluated. DCH regimen involved docetaxel and cyclophosphamide. The TCH regimen was a combination of docetaxel, carboplatin, and trastuzumab. The FEC-DH regimen was a combination of fluorouracil, epirubicin, and cyclophosphamide followed by docetaxel/trastuzumab. Patients were grouped according to node status and treatment. 

In patients with no cancer in the nodes (node-negative), survival rates at 5 years were similar in DCH and TCH groups (92.5% and 96.9%). Patients with additional medical conditions were 2.73 times more likely to have a lower survival without cancer.

In patients with cancer in their lymph nodes (node-positive), there were similar 5-year survival rates without cancer after FEC-DH (92.4%) and TCH (88.5%). 5-year overall survival was also similar after these chemotherapies (95.2% and 91.4%). 

The authors concluded that survival rates were similar across adjuvant chemotherapy regimens in patients with HER2+ BC.

This study looked back at medical records. Some information could not be included in the analysis. This may have an effect on the findings in this study.