Introduction/Background*Breast-Conserving Surgery (BCS) is considered a standard of care for women with early-stage breast cancer.

Achieving adequate margins of excision is a crucial component of breast surgery.

In our department, we routinely assess circumferential tumor cavity shaving (CTCS) status using frozen section analysis.

We sought to determine the effect of CTCS on reducing the rate of mastectomy with no residual disease.

Methodology We conducted a retrospective review of a prospectively maintained database of patients who underwent primary BCS for stage 0-III breast cancer between January 2015 and December 2019 in Salah Azaiez Institute of Oncology, Tunis, Tunisia.

We identified 142 patients who underwent conservative surgery with positive CTCS on histological examination.

Complementary treatment consisting in mastectomy was performed on all patients.

Result(s)*The mean age was 50. The average tumor size was 28 mm. The tumor was bifocal in 20%. 55% of tumors were Grade II SBR.

Invasive ductal carcinoma (IDC) was the most common histological subtype (74%). It was associated in 79% of cases with ductal carcinoma in situ (DCIS).

For the CTCS, 60% were DCIS, and 40% of the cases were invasive ductal carcinoma.

A complementary treatment consisting of mastectomy was indicated to all patients.

A residual tumor was detected in the remaining mammary gland in 60.4% of cases, out of which 39% were DCIS.

Chi-square test found that the presence of DCIS in CTCS, the lymphovascular invasion, and the size of tumors were not related to the presence of residual invasive or in-situ disease (p<0.05).

Conclusion*CTCS can help to detect residual or multifocal diseases.

Nevertheless, we need to find a way to avoid mastectomy with no residual disease in the remaining mammary gland.