The Effect of Receptor Status on Mastectomy and Contralateral Prophylactic Mastectomy Rates in Early Stage Invasive Breast Carcinoma.

Background: There is an established relationship between hormone receptor (HR; estrogen and/or progesterone receptors) status, HER2 status, and locoregional recurrence. The purpose of this study was to analyze how HR and HER2 receptor status have influenced the surgical management trends among patients with early stage breast cancer.
Patients and Methods: The National Cancer Database was queried for patients with cT1 to cT3, cN0, and cM0 breast carcinoma from 2004 to 2012. Patients were grouped on the basis of receptor status and surgical management (mastectomy or breast-conserving surgery [BCS]). Multivariable analyses were performed to investigate factors associated with increased odds of receiving mastectomy over BCS. Among a subgroup of patients who underwent ipsilateral mastectomy, analyses were performed to determine any association between contralateral prophylactic mastectomy (CPM) and receptor status.
Results: We found 280,241 patients who met inclusion criteria for analyzing mastectomy or BCS surgical decision. Patients with HER2-positive (HER2 ⁺ ) tumors (HR ⁺ /HER ⁺ and HR ^- /HER2 ⁺ ) were the most likely to undergo mastectomy (odds ratio [OR], 1.212 and 1.499 respectively, compared with HR ⁺ /HER2 ^- patients, each P < .001). HR status alone did not affect ipsilateral surgical management as patients with HR ⁺ /HER2 ^- and HR ^- /HER2 ^- tumors demonstrated similar mastectomy rates (P = .391). Among the 108,018 who underwent mastectomy, 20% underwent CPM. After adjustment, patients with HR ⁺ /HER2 ⁺ , HR ^- /HER2 ⁺ , and HR ^- /HER2 ^- were all more likely to undergo CPM (OR 1.356, 1.608, and 1.358, respectively compared with HR ⁺ /HER2 ^- patients, each P < .001).
Conclusion: This analysis indicates that patients with early stage breast cancer are more likely to undergo a mastectomy and CPM if they have HER2 ⁺ tumors.
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