Vasily Giannakeas, PhD, a researcher at Women's College Hospital Research and Innovation Institute
Among the most-read articles in JAMA Oncology last year - one of the highest-ranking oncology journals in the world - was a study from Women's College Hospital Research and Innovation Institute, a recognized leader in women's health research. Guided by the hospital's mission to challenge norms and drive breakthroughs, this landmark investigation challenged the perceived benefits of bilateral mastectomy for patients with unilateral breast cancer.
The study, led by Vasily Giannakeas, PhD, a researcher at Women's College Hospital Research and Innovation Institute, tracked 108,084 breast cancer patients over 20 years. It found that while bilateral mastectomy significantly reduces the risk of contralateral breast cancer, it does not lower the risk of breast cancer mortality compared to unilateral mastectomy or lumpectomy.
The findings raise several fundamental questions about the nature of breast cancer with potential implications for the screening, treatment and survivorship of the disease.
Key Findings:
The study involved three equally matched groups of breast cancer patients (n = 36,028 each) who underwent either unilateral mastectomy, lumpectomy, or bilateral mastectomy.
This comprehensive study raises important questions about the metastatic potential of a new contralateral breast cancer and the true benefits of bilateral mastectomy for unilateral breast cancer patients. Despite the reduced incidence of contralateral cancer, the similar mortality rates suggest that bilateral mastectomy may not offer the survival benefit many patients and clinicians expect.
“Traditionally, it is assumed that a contralateral breast cancer is a new primary cancer with the potential to metastasize and thus impact overall survival negatively," says Giannakeas. “However, the similar mortality rates across all surgical groups suggest that the occurrence of contralateral cancer may be more of a marker of an already existing higher risk of mortality rather than an independent cancer event that drives an increase in mortality."
The study also raises important questions about the effectiveness of current screening strategies and adjuvant therapies, such as chemotherapy, in the treatment of contralateral breast cancer.
“About one-third of patients with contralateral breast cancer are treated with chemotherapy, “says Giannakeas. “However, it now seems we are trying to treat the first cancer and chemotherapy may not be as effective. These are compelling questions that we hope to address in future studies."
“For now, this research's findings are valuable to the patient and their physician as they look to decide on surgical options to treat breast cancer."