Impact of routine expert breast pathology consultation and factors predicting discordant diagnosis.

BACKGROUND: This study aimed to evaluate the impact of expert breast pathology consultation on operative management and predictive factors of discordant diagnosis. METHODS: A retrospective review of patients referred with breast biopsies and subsequent expert pathology consultation from 2014 to 2019. Discordance in diagnosis and documented changes in therapy were recorded. Univariate and multivariable analyses were performed. RESULTS: Ninety-one (91/263, 35%) patients had discordant findings after expert pathology consultation. No benign or in situ diagnoses were upgraded to invasive cancer. Tumor subtype changed in 10% while change in invasive cancer grade was most common (45%). Clinical management was altered in 3/263 (1%) with one change in surgical plan. Benign lesions without atypia (7.5% vs. 1.1%, p = 0.03) and excisional biopsies (8.7% vs. 2.2%, p = 0.04) were more often associated with non-discordant pathology. No independent predictors of discordance were observed. CONCLUSIONS: Discordant diagnoses after expert pathology consultation are common despite few changes in operative management. Excisional biopsy and benign lesions without atypia may be associated with less pathologic discordance after expert review.

Effect of the Ductal Carcinoma In Situ Margin Consensus Guideline Implementation on Re-Excision Rates, Satisfaction, and Cost.

INTRODUCTION: The 2016 consensus guideline on margins for breast-conserving surgery (BCS) with whole-breast irradiation (WBI) for ductal carcinoma in situ (DCIS) recommended 2 mm margins to decrease local recurrence rates. We examined re-excision rates, cost, and patient satisfaction before and after guideline implementation. METHODS: From an Institutional Review Board-approved database, patients with DCIS who underwent BCS with over 1 year of follow-up at one academic institution and one community cancer center were evaluated. Two groups were compared based on when they received treatment, i.e. before (pre-consensus [PRE]) and after November 2016 (post consensus [POST]), with respect to outcome and cost parameters. RESULTS: After consensus guideline implementation, re-excision rate (32.1% vs. 20.0%) and mastectomy conversion (8.3% vs. 2.3%) significantly increased, although total resection volume, operative cost per patient, and satisfaction with breast scores did not differ. Not all patients with <2 mm margins were re-excised, although the re-excision rate among this subset significantly increased (62.4% vs. 31.3%). On multivariable analysis controlling for age, estrogen receptor status, WBI use, and margin status, surgery after consensus guideline publication was independently associated with a higher re-excision rate (odds ratio [OR] 1.97, 95% confidence interval [CI] 1.08-3.59, p = 0.03) and a higher rate of conversion to mastectomy (OR 6.84, 95% CI 1.67-28.00, p = 0.007). CONCLUSIONS: Implementation of the 2016 margin consensus guideline for DCIS resulted in an increase in re-excisions and mastectomy conversions at two institutions. Research is needed for operative tools and strategies to decrease DCIS re-excision rates.

Evaluating the effect of neoadjuvant chemotherapy on surgical outcomes after breast conserving surgery.

BACKGROUND: Neoadjuvant chemotherapy (NAC) increases breast-conserving surgery (BCS) rates with comparable locoregional control and survival outcomes to adjuvant therapy. More women are receiving NAC and achieving pathologic complete responses (pCR). This study sought to evaluate the effect of NAC on surgical outcomes after the adoption of a "no-ink-on-tumor" margin policy in patients undergoing primary BCS (PBSC). METHODS: An IRB approved database was queried for women undergoing BCS for invasive breast cancer after March 2014. We compared patients who underwent NAC followed by BCS versus PBCS. Demographic, tumor, treatment, and outcome variables were compared using both univariate and multivariable analysis. RESULTS: A total of 162 patients were evaluated. NAC patients had significantly lower re-excision rates (0% NAC vs. 9% PBCS, p = .03), margin positivity (0% NAC vs. 5% PBCS, p = .01), and greater patient satisfaction with breast cosmesis (97 NAC vs. 77 PBCS, p = .01). On multivariable analysis, NAC was not an independent predictor of lower final resection volume, total complications, or greater satisfaction with breasts when controlling for age and T category at diagnosis. CONCLUSION: NAC followed by BCS may offer less margin positivity, lower re-excision rates, and greater patient satisfaction when compared to a contemporary PBCS cohort in the "no-ink-on-tumor" era.