Mammogram Surveillance Outcomes After Oncoplastic or Standard Breast Conserving Surgery in Asians-A Comparison Study Exploring the Effect of Breast Density.

PURPOSE: Oncoplastic breast conserving surgery (OBCS) allows larger tumor resections while preserving breast cosmesis. However, the impact of more extensive tissue rearrangements in OBCS on mammographic surveillance in Asian women with typically denser breasts remains unclear. This study aimed to determine how OBCS and standard wide local excisions (SWLE) impacts mammographic surveillance outcomes in Asian women and to evaluate how breast density affects mammogram assessments.

METHODS

This multicenter retrospective study compared breast cancer patients who underwent OBCS or SWLE in three Singaporean breast centers from 2013 to 2017. Surveillance mammograms performed within 5 years postsurgery were reviewed for recall rates, biopsy rates, sensitivity, and specificity. Mammographic findings were correlated with breast density.

RESULTS

The study evaluated 120 OBCS cases (55.5% volume displacement, 44.5% volume replacement) and 253 SWLE cases, with 517 and 1148 screening surveillance mammograms performed up to a 5-year period respectively. OBCS recall rates were 17.2% in the 1st-2nd postoperative years, compared to SWLE rates of 11.8% (P = .057). Biopsy rates were identical between groups (1.4%). Asymmetric densities and calcifications were primary causes for false positive recalls. Dense breasts were observed in 63.8% and 73.3% of OBCS and SWLE mammograms respectively. All false negative recurrences in both groups occurred in patients with dense breasts (n = 8).

CONCLUSION

Surveillance mammograms following OBCS showed a trend towards higher recall rates than SWLE in the first 2 postoperative years due to imaging work-up of surgical site changes. However, biopsy rates remained low. Recall rates were not affected by breast density, although dense breasts were related to mammographically occult cancer recurrences.