Title:
The impact of re-excision and residual disease on local recurrence after breast conservation treatment for patients with early stage breast cancer.

Abstract:
The current study examined the impact of re-excision and residual disease on local recurrence after breast conservation treatment for patients with negative margins. Patients with residual disease on re-excision had a higher local recurrence rate than other patients. However, with reasonably low local recurrence rates in all subgroups, neither re-excision nor residual disease on re-excision are contraindications for breast conservation treatment.
To evaluate the impact of re-excision and the presence of residual disease on local recurrence for patients who underwent breast conservation treatment (BCT) with negative final resection margins.
The records of 902 patients with stage I or II unilateral invasive breast cancer who had BCT were reviewed. The study cohort consisted of patients with negative final resection margins and was divided into 3 subgroups: (a) single excision (n = 332 [37%]), (b) re-excision with no residual disease in the re-excision specimen (n = 440 [49%]), and (c) re-excision with residual disease in the re-excision specimen (n = 130 [14%]). The median follow-up was 6.75 years.
At 15 years, the rates of local failure were 10% for patients with a single excision, 10% for patients with a re-excision without residual disease, and 16% for patients with a re-excision with residual disease (P = .033). There were no significant differences between the 3 groups for overall survival, cause-specific survival, relapse-free survival, or freedom from distant metastases (all P ≥ .082). Multivariate analysis demonstrated an increased risk of local failure for patients with residual disease in the re-excision specimen that was borderline statistically significant (hazard ratio, 2.16; P = .061).
Despite achieving negative final resection margins, the patients with residual disease in the re-excision specimen had a higher rate of local recurrence than patients who underwent single excision or patients without residual disease on re-excision. However, local recurrence was reasonably low in all 3 subgroups, and, therefore, neither re-excision nor residual disease represent contraindications for BCT.