Contemporary breast conservation patient outcomes for ductal carcinoma in situ and margins < 2 mm.

Abstract

559 Background: Recent national consensus guidelines regarding optimal margin width for the management of DCIS have been published; however, controversy remains for managing margins &lt;2mm. The relationship between margin width and locoregional recurrence (LRR) was determined in a contemporary cohort of patients. Methods: 1504 patients with DCIS undergoing definitive breast conserving surgery from 1996 to 2010 were analyzed for clinical and pathologic characteristics from a prospectively managed comprehensive academic cancer center database. Cox proportional hazard models were used to examine the relationship between margin width (&lt;2mm or ≥2mm) and LRR by adjuvant radiation therapy (RT). Patients with positive margins (n=11) were excluded. Results: Overall, 3.4% of patients had a LRR at a median follow-up of 8.7 years. Univariate analysis of age, family history, grade, tumor size, comedonecrosis, RT, adjuvant hormonal therapy, ER status, and margin width found younger age (&lt; 40 yr, p=0.02), no RT (n=299, p=0.005), and margin width &lt;2mm(n=138, p=0.005) to be associated with LRR. The association between margin width and LRR differed by adjuvant radiation therapy status (p=0.02 for the interaction). There was no statistical significant difference in LRR for patients with margins &lt;2mm vs ≥2 mm who received RT, (10-year LRR 6.0% vs 3.2%, respectively; HR 1.5, 95% CI 0.5-4.2, p=0.48). For patients who did not receive RT (n=299), those with margins &lt; 2 mm were significantly more likely to develop a LRR than those with margins ≥2mm (10-year LRR 35.7% vs. 4.6%, respectively; HR 7.2, 95%CI 2.6-19.4, p=0.0001). Conclusions: In patients with &lt;2mm margins receiving adjuvant radiation therapy, there is no difference in locoregional recurrence when compared to patients with ≥2mm margins. Additional surgery for wider margins of resection are not routinely justified in this group of patients but should be obtained for patients with &lt;2mm margins who forego radiotherapy.

Ductal Carcinoma In Situ of the Breast: An Update with Emphasis on Radiological and Morphological Features as Predictive Prognostic Factors

“…A different perspective comes from the American Society of Breast Surgeons that considers exclusively "no ink on the tumor" as a negative margin [33]. Notably the MD Anderson experience [34], corroborated by the Memorial Sloan Kettering Cancer Center [35], reported that the difference in Local recurrence rate (LRR) for patients with margins <2 mm vs. ≥ 2 mm (10-year LRR 30.9% vs. 5.4%, respectively; p = 0.003) was abrogated in patients receiving radiotherapy (10-year LRR 4.8% vs. 3.3%, respectively; p = 0.72). As many authors state that the strongest predictor of local recurrence of DCIS after BCS is a positive surgical margin at the time of initial surgery, a careful macroscopic sampling and microscopic examination must be carried out.…”

DCIS Margins and Breast Conservation: MD Anderson Cancer Center Multidisciplinary Practice Guidelines and Outcomes

“…We recently updated this cohort with additional patients and longer follow-up and analyzed outcomes. We identified 1,491 patients with DCIS undergoing definitive BCS from 1996 to 2010 14 , 15 . Cox proportional hazard models were used to examine the relationship between margin width (< 2 mm or ≥ 2 mm) and local - regional recurrence (LRR) by receipt of adjuvant radiation therapy (RT).…”

“…Radiopaque clips are placed routinely in the resection cavity to facilitate identification of the area for radiation therapy and to facilitate the use of a boost when indicated. Although the median size of DCIS cases treated with BCS over the past 20 years at MD Anderson is only 1 cm, during the same time period the use of oncoplastic surgery has allowed for an increasing number of patients with an unfavorable tumor location to become BCS-eligible 14 , 32 . Essentially, if all malignant appearing calcifications can be removed utilizing this approach and the margins are negative, there is no absolute size criteria utilized at our institution for the selection of patients for BCS in the treatment of DCIS.…”

“…Initially, at MD Anderson as well as within the National Comprehensive Cancer Network, endocrine therapy use and adherence was low 57 , 58 . In our updated analysis, approximately 57% of patients with ER-positive DCIS take endocrine therapy following BCS for DCIS 14 . The choice of specific endocrine therapy in postmenopausal women with DCIS is tailored according to the side effect profile and patient preference.…”

“…There was no statistical significant difference in LRR for patients with margins < 2 mm vs ≥ 2 mm who received RT, (10-year LRR 4.8% vs 3.3%, respectively; p=0.72; B). For patients who did not receive RT, those with margins < 2 mm were significantly more likely to develop a LRR than those with margins ≥ 2 mm (10-year LRR 30.9% vs. 5.4%, respectively; p=0.003; C) 14 , 15 ; with permission from Annals of Surgery . Promotional and commercial use of the material in print, digital or mobile device format is prohibited without permission from the publisher Wolters Kluwer.…”