The impact of residual cancer removed during subsequent surgeries on the outcome of patients with localized breast cancer

Abstract

e11533 Background: A close or positive margin after breast cancer surgery is an important risk factor for local recurrence. A significant percentage of breast cancer patients need additional surgeries to obtain clear margins. This study evaluated the impact of residual cancer (RC) found upon subsequent operations on the outcome of the patients with localized breast cancer. Methods: Under IRB approved protocol, we retrospectively analyzed data on 573 patients with stage I-IIIA breast cancer treated at our institution during 1994–2004. 202 patients had complete tumor removal at single procedure with clear margins, 319 patients had subsequent surgery due to initially compromised margins and 52 patients with compromised margins did not have second surgery. Cox Proportional Hazard regression test was performed to evaluate the effect of RC found on subsequent surgery on distant recurrence (DR) and disease specific survival (DSS). Results: Median follow-up was 5.4 years. Among 319 patients who underwent second surgery, 57.7% did not have any RC; 13.1% had in situ RC and 29.2% had invasive RC. 12.9% (74/573) patients had DR. The risk of DR was higher in patients with RC found upon second surgery compared to those who had single procedure breast cancer removal (22.6% vs. 9.9%; HR 2.4, 95% CI 1.3–4.4, p=0.006). Similarly, finding of RC was a significant predictor of DSS (80.6% vs.92.6%; HR 2.9, 95% CI 1.4–5.7, p=0.003). Multivariate analysis revealed that tumor size above 5 cm, lymph nodes involvement and grade III were significant predictors of DR and DSS along with invasive RC found during subsequent surgeries. Delay in adjuvant chemotherapy due to need for subsequent surgeries strongly correlated with earlier DR in patients with invasive RC found on subsequent operations (rS = - 0.55, p = 0.019, two-tailed). Conclusions: Invasive residual carcinoma found during subsequent surgery after initial compromised margin is an important prognostic factor for DR and DSS, even after clear margins are eventually achieved. No significant financial relationships to disclose.