Breast Cancer

Navigators play a vital role in outreach to underserved communities by providing access to cancer care.

The past week in oncology-related news includes shortages of crucial pediatric cancer drug, results of a study of racial disparities in multiple myeloma, and new drug on the horizon for HER2 metastatic breast cancer.

Two human genes, BRCA1 and BRCA2 (BRCA1/2), produce proteins that block the growth of cancer, such as breast or ovarian cancer. These proteins ensure the stability of each cell’s genetic material and help to repair damaged DNA. A mutation in either BRCA results in these proteins not functioning correctly. Specifically, DNA damage may not be repaired effectively, which can lead to cancer.

On May 3, 2019, the US Food and Drug Administration (FDA) approved ado-trastuzumab emtansine (Kadcyla; Genentech) for the adjuvant treatment of patients with HER2-positive early breast cancer who have residual invasive disease after neoadjuvant taxane and trastuzumab-based treatment. Patients should be selected for treatment with this agent based on an FDA-approved companion diagnostic test (Ventana Medical System’s PATHWAY anti-HER-2/neu [4B5] Rabbit Monoclonal Primary Antibody assay or INFORM HER2 Dual ISH DNA Probe Cocktail assay).

Options for the treatment of patients with advanced hormone receptor (HR)-positive, HER2-negative breast cancer are expanding.

The adjuvant use of the antibody-drug conjugate trastuzumab emtansine (T-DM1) led to a clinically meaningful and statistically significant improvement in invasive disease-free survival versus trastuzumab in patients with HER2-positive early breast cancer and residual invasive disease, despite the use of neoadjuvant chemotherapy plus HER2-targeted therapy, according to the preliminary results from the phase 3 KATHERINE trial reported at the 2018 San Antonio Breast Cancer Symposium.

The large, randomized TAM-01 clinical trial demonstrated that 5-mg daily of tamoxifen for 3 years halved the risk for recurrence of breast intraepithelial neoplasia—atypical ductal hyperplasia, ductal carcinoma in situ (DCIS), and lobular carcinoma in situ—in women after surgery and reduced the risk for new contralateral breast cancer by 75% compared with placebo.

Atezolizumab plus nab-paclitaxel was the first immunotherapy combination to improve disease-free survival (DFS) and overall survival (OS) in women with metastatic triple-negative breast cancer (TNBC) versus placebo plus nab-paclitaxel in the overall analysis of the IMpassion130 trial. Survival improvement was even more robust in the PD-L1–positive cohort.

Reaching pathologic complete response (pCR) after neoadjuvant chemotherapy correlates with significantly improved event-free survival (EFS) and overall survival (OS) in patients with localized breast cancer, according to a large comprehensive meta-analysis presented at the 2018 San Antonio Breast Cancer Symposium.

On April 4, 2019, the US Food and Drug Administration (FDA) expanded the indication of palbociclib (Ibrance; Pfizer), a kinase inhibitor, in combination with specific endocrine therapies for men with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer. This is the first hormonal-based therapy to be approved for men.