Tumor-to-Breast Volume Ratio and Outcomes After Oncoplastic Breast Conserving Surgery

Oncoplastic breast conserving surgery (OBCS) can offer oncologically safe and cosmetically satisfying results for patients with breast cancer. However, the relative oncologic safety of high tumor-volume oncoplastic resections is largely unknown. This study investigated the association between tumor-to-breast volume ratio, recurrence, and surgical complications in OBCS. The relationship between tumor-to-breast ratio and quality of life was also assessed.

A retrospective review was performed for all women who underwent OBCS for breast cancer between 2010 and 2023 at a university-based tertiary referral center. The BREAST-Q questionnaire was utilized to assess quality of life outcomes. Tumor-to-breast ratio was calculated by dividing lumpectomy specimen volume by total breast volume. Surgical complications, reexcision, local recurrence, and revision procedures were noted. Multivariate logistic regression was performed to assess the association of tumor-to-breast ratio with outcomes.

This study included 192 patients, of which 65 (34%) completed the BREAST-Q. Median tumor-to-breast volume ratio was 7.3% (IQR, 3.6%-12.5%). Quartiles of tumor-to-breast ratio were not associated with local cancer recurrence rate (P = 0.50), reexcision (P = 0.29), wound-related complications (P = 0.45), complications requiring reoperation (P = 0.34), and elective revision of reconstruction (P = 0.67). BREAST-Q scores for Psychosocial Well-being, Physical Well-being, and Overall Satisfaction were similar across tumor-to-breast ratio. Cancer worry was significantly higher in larger tumor-breast ratio quartiles (P = 0.03).

These data suggest that OBCS is a reasonable approach for patients with higher tumor-to-breast ratio. Complications and quality of life metrics did not appear to vary significantly with increasing tumor size, except for "cancer worry," which was higher among patients with larger tumor-breast ratio patients.