Breast cancer research and treatment
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Breast Cancer Res. Treat. · Nov 2016
Impact of neoadjuvant therapy on eligibility for and frequency of breast conservation in stage II-III HER2-positive breast cancer: surgical results of CALGB 40601 (Alliance).
It had been previously shown that patients who receive neoadjuvant systemic therapy (NST) are more likely to undergo breast-conserving therapy (BCT) than those who have primary surgery. However, the frequency with which patients who are not BCT-eligible prior to NST convert to BCT-eligible with treatment is unknown. To document this conversion rate in a subset of patients expected to have a high clinical response rate to NST, we studied surgical assessment and management of patients enrolled on a randomized neoadjuvant trial for stage II-III HER2-positive breast cancer (HER2 + BC)(CALGB 40601). ⋯ Many patients with HER2 + BC deemed ineligible for BCT at baseline can be converted to BCT-eligible with NST; excluding patients with multicentric disease substantially increases that percentage. In converted patients who opt for BCT, the success rate is similar to that of patients considered BCT-eligible at baseline. Whether a BCT-ineligible patient converts to BCT eligibility or not does not appear to affect the likelihood of achieving a pCR. Despite the efficacy of NST in this patient cohort, only 40 % of patients had successful BCT; further research into why BCT-eligible patients often opt for mastectomy is needed.