Factors correlating with reexcision after breast-conserving therapy.

AIM The aim of this study was to evaluate factors affecting the risk for reexcision following breast-conserving surgery. Positive tumor margins are critical for local disease control following surgery for breast cancer. Several factors, including tumor size, multifocality, and an extensive in situ component, may be associated with a higher rate of repeat operations due to positive margins. This study included mammographic density in the analysis. METHODS A total of 565 breast cancer patients were considered eligible for breast-conserving therapy after a core biopsy had confirmed malignancy. The patients' mammographic findings were reviewed, and mammographic density was documented in addition to the histopathological features of the lesions. Associations between these factors and the risk for a second operation were analyzed using the chi-squared test, and a model was developed for multivariate analysis. RESULTS At least one repeat operation was necessary in 121 patients (21.4%), and mastectomy was ultimately necessary in 54 patients (9.6%). Tumor size, multifocality, and the presence of an in situ component were identified as risk factors. A mammographic density of category 4 was associated with a need for further surgery (OR 3.2; 95% CI, 1.2-11). CONCLUSIONS Mammographic density is an additional risk factor for a second operation following breast-conserving procedures, and it may make radiographic and intraoperative localization of the tumor technically difficult. Using mammographic density to define a group of patients with a higher risk of reexcision might allow these patients to benefit from more sophisticated methods of localization and margin assessment.