Objective and design: Some surgeons consider excisional biopsy with gross negative margins to be adequate surgical therapy for breast carcinomas, if followed by axillary dissection and radiation. To test our hypothesis that breast carcinoma necessitates planned operation, we reviewed the incidence of residual cancer tissue (RCT) and the significance of positive margins following excisional breast biopsy and segmentectomy. SETTING, PATIENTS, AND INTERVENTION/OUTCOME MEASURES: Using the clinical database of our multidisciplinary cancer center, we examined the tumor status of segmentectomy specimens from 375 patients treated for breast carcinoma during the past 10 years. All patients underwent excisional biopsy of the tumor mass before definitive treatment with segmentectomy and axillary dissection. Median follow-up was 32 months.
Results: The 284 patients (76%) whose segmentectomy specimens contained residual tumor (RCT-positive patients) had a larger median tumor diameter than RCT-negative patients (2 vs 1 cm, P < .01). Patients with tumor-positive axillary lymph nodes were more likely to be RCT positive (P < .001). Tumors of RCT-positive patients were more frequently identified by physical examination, whereas those of RCT-negative patients were more frequently identified by mammography (P < .001). Overall recurrence rate was 7% (26/384). Recurrence-free survival rates were statistically related to tumor status of the segmentectomy margins (P < .025) but not to RCT in the segmentectomy specimen.
Conclusion: Diagnostic breast biopsy is not a substitute for planned excision to remove all malignant tissue. Anything less than a preconceived surgical procedure may leave a significant amount of malignant tissue.