Abstract: Pathologic Evaluation of Reduction Mammaplasty Specimens and Subsequent Diagnosis of Malignant Breast Disease: A Nationwide Analysis

PURPOSE: Reduction mammaplasty is one of the most common plastic and reconstructive procedures performed in the United States. Surgeons routinely submit breast specimens for evaluation after reduction mammaplasty owing to the nature of breast surgery. However, no rigorous evidence informs the necessity of routine pathologic evaluation of breast reduction specimens based on patient factors. This study sought to measure the use of pathologic evaluation of breast specimens among patients undergoing reduction mammaplasty and assess the rates of new diagnoses of malignant breast disease and associated cost for reduction mammaplasty surgical encounters. We hypothesized that pathologic evaluation would be widely utilized following reduction mammaplasty despite increased cost of care and relatively low rates of subsequent malignant breast disease, particularly among patients in low-risk age groups. METHODS and MATERIALS: We analyzed the Truven MarketScan Databases from 2009 – 2015 to identify female patients age 18 years and older undergoing reduction mammaplasty for macromastia. Patients were excluded if they were not observed at least 12 months before and after the operation, if they had genetic susceptibility to breast cancer, prior benign or nonspecific breast disease, or prior personal/family history of breast cancer. We recorded patient age, patients receiving pathologic evaluation of the breast specimens (gross or microscopic), new diagnoses of benign or malignant breast disease after pathologic evaluation, and total cost for the reduction mammaplasty encounters, including all services delivered on the same date as surgery and cost for pathologic examination of breast specimens within 7 days of surgery. We performed descriptive statistics to assess age-based rates of pathologic evaluation following reduction mammaplasty and new diagnoses of benign or malignant breast disease after pathologic evaluation. We also compared the total cost for reduction mammaplasty for encounters with and without use of pathologic evaluation. RESULTS: We identified 17,738 macromastia patients undergoing reduction mammaplasty, of which 91.3% (n=16,193) received pathologic evaluation breast tissue specimens. Use of pathologic evaluation was clinically similar across age groups <70 years (90.8–92.1%), and slightly lower for patients 70 and older (85.0%). Of patients who received pathologic evaluation, 99.7% (n=16,140) received microscopic evaluation. Among 7,610 patients 39 years and younger, 0.05% (n=4) were subsequently diagnosed with malignant breast disease within 3 months of surgery, compared to 0.25% in the entire cohort (n=44/17,738). Patients who received pathologic evaluation after reduction mammaplasty had $918 greater costs on average (mean $12,387; SD 9,348), compared to patients who did not receive pathologic evaluation (mean $11,469; SD 11,623). CONCLUSION: Breast tissue after reduction mammaplasty is routinely submitted for pathologic evaluation, without consideration of age-based risk for breast cancer. Routine pathologic evaluation of breast tissue in patients 39 years and younger required an additional $1.7 million on average to detect a single occult breast cancer after reduction mammaplasty. In the quest for high-value care, clinicians and policy-makers should consider whether the practice of routine pathologic evaluation of breast tissue should be individualized based on patient age and other risk factors for breast disease.