Occurrence of residual disease in specimens of re-excision surgery in patients with positive margins of primary quadrantectomy.

Performing a re-intervention following a positive margin after primary lumpectomy in patients with breast cancer entails several disadvantages such as additional costs and postponing the follow-up treatments. In the present study, we sought to measure the incidence rate of residual disease in specimens taken from breast cancer patients who had positive margins after quadrantectomy and also compare the clinical and pathological factors between patients with and without a residual disease after the secondary surgery. All of the medical records of patients undergoing quadrantectomy from December 1994 to December 2019 were collected from Shiraz Breast Cancer Registry (SBCR). Patients were divided into two subgroups of patients with and without residual disease from the secondary surgery and also with and without positive margin from the first operation. Two groups were compared in terms of all clinicopathological factors. The records of 4843 patients undergoing quadrantectomy were reviewed, of which 132 (2.3%) had involved margins. Of these, 112 patients underwent a secondary surgery and 28 had residual disease (25%). No clinicopathological factor was correlated with presence of residual cancer. Also, bigger tumor size (p < 0.001) and the presence of in situ component (p < 0.001) were associated with positive margin and hence the need for a re-excision surgery. These results revealed that the significant rate of residual disease in the specimens of the secondary surgery indicates that a re-operation (either re-excision or simple mastectomy) cannot be omitted after obtaining a positive margin from the primary quadrantectomy.