ASO Author Reflections: Avoiding Mastectomy: The Benefit of Neoadjuvant Chemotherapy for Large Unifocal Breast Tumors

Excerpt

In patients with operable breast cancer, neoadjuvant chemotherapy (NAC) can be used to downstage the primary tumor and increase rates of breast-conserving surgery (BCS).1 Although randomized trials have shown higher rates of BCS after NAC compared with upfront surgery,2 these trials included patients who were BCS candidates pre-NAC, thus limiting our understanding of the true benefit of NAC for downstaging. More recent trials, including Cancer and Leukemia Group (CALGB) 40601 and 40603, prospectively evaluated conversion rates from BCS-ineligible to BCS-eligible with NAC in HER2+ and triple negative breast cancer patients, respectively. While the prospective assessment of BCS eligibility pre- and post-NAC was a major strength of these studies, their findings were limited by the inclusion of patients with clinical T4 and multicentric tumors, factors which traditionally preclude downstaging.3^,4 Therefore, we sought to prospectively assess rates of conversion to BCS with NAC in patients considered BCS-ineligible because of a large tumor size relative to breast size—a subset ideally suited for downstaging. …