Intraoperative Pathologic Margin Analysis and Re-Excision to Minimize Reoperation for Patients Undergoing Breast-Conserving Surgery

BACKGROUND

Reoperation rates following breast-conserving surgery (BCS) range from 10 to 40%, with marked surgeon and institutional variation.

OBJECTIVE

The aim of this study was to identify factors associated with intraoperative margin re-excision, evaluate for any differences in local recurrence based on margin re-excision and determine reoperation rates with use of intraoperative margin analysis.

PATIENTS AND METHODS

We analyzed consecutive patients with ductal carcinoma in situ (DCIS) or invasive breast cancer who underwent BCS at our institution between 1 January 2005 and 31 December 2016. Routine intraoperative frozen section margin analysis was performed and positive or close margins were re-excised intraoperatively. Univariate analysis was used to compare margin status and the Kaplan-Meier method was used to compare recurrence. Multivariable logistic regression was utilized to analyze factors associated with re-excision.

RESULTS

We identified 3201 patients who underwent BCS-688 for DCIS and 2513 for invasive carcinoma. Overall, 1513 (60.2%) patients with invasive cancer and 434 (63.1%) patients with DCIS had close or positive margins that underwent intraoperative re-excision. Margin re-excision was associated with larger tumor size in both groups. The permanent pathology positive margin rate among all patients was 1.2%, and the 30-day reoperation rate for positive margins was 1.1%. Five-year local recurrence rates were 0.6% and 1.2% for patients with DCIS and invasive cancer, respectively. There was no difference in recurrence between patients with and without intraoperative margin re-excision (p = 0.92).

CONCLUSION

Both DCIS and invasive carcinoma had similar rates of intraoperative margin re-excision. Although intraoperative margin re-excision was common, the reoperation rate was extremely low and there was no difference in recurrence between those with or without intraoperative re-excision.

Is higher dose radiation necessary for positive resection margin after breast-conserving surgery for breast cancer?

BACKGROUND

A positive resection margin after breast-conserving surgery (BCS) usually requires re-excision, which impairs cosmetic outcomes and causes considerable distress. This study aimed to evaluate the prognosis of patients with positive resection margin after BCS and the role of radiation therapy (RT) in these patients.

MATERIALS AND METHODS

We analyzed 297 patients who underwent BCS for breast cancer and had invasive carcinoma or ductal carcinoma in situ (DCIS) within less than 1 mm from the resection margin in Samsung Medical Center from January 2000 to June 2012. The association between RT dose and the incidence rate of ipsilateral breast tumor recurrence (IBTR) was examined.

RESULTS

After a median follow-up of 78 months, the incidence rate of IBTR in all patients was 4.6% after 5 years. In the multivariate analysis, the unfavorable factors associated with IBTR were age < 40 years (p = 0.019), RT dose (<60 Gy vs. > 66 Gy, p = 0.012; 60-66 Gy vs. > 66 Gy, p = 0.017), and discontinuation of hormone therapy (p = 0.001).

CONCLUSIONS

Among the patients with invasive carcinoma or DCIS within less than 1 mm from the resection margin, adjuvant RT with higher dose > 66Gy EQD2 might improve local control. Further prospective studies are warranted to validate the benefit and risk of a high dose boost after BCS in patients with a positive resection margin.

Factors Associated With Positive Margins in Women Undergoing Breast Conservation Surgery

OBJECTIVE

To identify factors predicting positive margins at lumpectomy prompting intraoperative reexcision in patients with breast cancer treated at a large referral center.

PATIENTS AND METHODS

We reviewed all breast cancer lumpectomy cases managed at our institution from January 1, 2012, through December 31, 2013. Associations between rates of positive margin and patient and tumor factors were assessed using χ² tests and univariate and adjusted multivariate logistic regression, stratified by ductal carcinoma in situ (DCIS) or invasive cancer.

RESULTS

We identified 382 patients who underwent lumpectomy for definitive surgical resection of breast cancer, 102 for DCIS and 280 for invasive cancer. Overall, 234 patients (61.3%) required intraoperative reexcision for positive margins. The reexcision rate was higher in patients with DCIS than in those with invasive disease (78.4% [80 of 102] vs 56.4% [158 of 280]; univariate odds ratio, 2.80; 95% CI, 1.66-4.76; P<.001). Positive margin rates did not vary by patient age, surgeon, estrogen receptor, progesterone receptor, or ERBB2 status of the tumor. Among the 280 cases of invasive breast cancer, the only factor independently associated with lower odds of margin positivity was seed localization vs no localization (P=.03).

CONCLUSION

Ductal carcinoma in situ was associated with a higher rate of positive margins at lumpectomy than invasive breast cancer on univariate analysis. Within invasive disease, seed localization was associated with lower rates of margin positivity.

Focally positive margins in breast conserving surgery: Predictors, residual disease, and local recurrence

BACKGROUND

Re-excision after breast conserving surgery (BCS) for invasive breast cancer (IBC) can be omitted for focally positive margins in the Netherlands, but this guideline is not routinely followed. Focally positive and extensively positive margins have rarely been studied separately and compared to negative margins regarding clinicopathological predictors, residual disease incidence, and local recurrence.

METHODS

All females with BCS for Tis-T3, without neo-adjuvant chemotherapy between 2005 and 2014 at one university hospital were included. Clinicopathological and follow-up information was collected from electronic patient records. Index tumor samples from all patients with re-excision were reviewed by one pathologist. Margins were classified as negative (≥2 mm width), close (<2 mm width), focally positive (≤4 mm length of tumor touching inked margin), or extensively positive (>4 mm length).

RESULTS

From 499 patients included, 212 (43%) had negative, 161 (32%) had close, 59 (12%) had focally positive, and 67 (13%) had extensively positive margins. Increasingly involved margins were associated with lobular type, tumor size, and adjacent DCIS in IBC patients and lesion size in purely DCIS patients. In IBC patients, 17%, 49%, and 77% had re-excision after close, focally positive, and extensively positive margins and residual disease incidence was 55%, 50%, and 70% respectively. In purely DCIS patients, 26 (65%), 13 (87%), and 16 (94%) had re-excision after close, focally positive, and extensively positive margins and residual disease incidence was 39%, 46%, and 90% respectively.

CONCLUSION

Incidence of residual disease after focally positive margins was not different from close margins, but was significantly higher after extensively positive margins. We recommend quantifying extent of margin involvement in all pathology reports.