title: Extent of margin positivity as a predictor for local recurrence after breast conserving irradiation.
abstract: The extent of positivity of the final excision margin in relationship to other relevant factors was evaluated as a predictor for local recurrence after breast conservation therapy (BCT). As part of an institutional practice policy for BCT in 509 stage I/II breast carcinomas, 105 cases had a final excision margin, which was positive. The median age for this cohort was 58 years and the median follow-up was 86 months. All positive margin patients received whole breast irradiation to 50 Gy-50.4 Gy followed by a boost to the tumor bed for an additional 20 Gy. The extent of positivity (EOP) of the excision margin was graded according to a four-point scale: focal, minimal, moderate, extensive. Cases were then analyzed for local failure according to EOP grade, histology, age, tumor size, total excision volume, re-excision, tamoxifen therapy, and chemotherapy. A focal or minimal EOP grade was found in 70% of specimens while an additional 26% were moderate or extensive. The incidence of invasive carcinoma with prominently associated DCIS was significantly greater in cases with an EOP grade of moderate/extensive. There were nine ipsilateral breast recurrences, eight of which could be evaluated for EOP grade. All recurrences were in or near the previous biopsy cavity. A Kaplan-Meier plot of freedom from local failure showed a significant (P = 0.008) difference between cases grouped by EOP grade of focal/minimal as compared to moderate/extensive. A Cox proportional hazards regression model found that the only variable significantly related at the P < or = 0.05 level to local failure was an EOP grade of moderate/extensive. For breast excision specimens with a positive final margin, an EOP grade of moderate/extensive is a predictor for local recurrence after BCT, which may be independent of other variables such as age or histology.
authors.affiliation: Department of Radiation Oncology, New England Medical Center, Tufts University School of Medicine, Boston, Massachusetts 02111, USA. david.wazer@es.nemc.org
authors.forename: D E
authors.initials: DE
authors.lastname: Wazer
authors.forename: G
authors.initials: G
authors.lastname: Jabro
authors.forename: R
authors.initials: R
authors.lastname: Ruthazer
authors.forename: C
authors.initials: C
authors.lastname: Schmid
authors.forename: H
authors.initials: H
authors.lastname: Safaii
authors.forename: R K
authors.initials: RK
authors.lastname: Schmidt-Ullrich
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D001706:Biopsy; D001943:Breast Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008408:Mastectomy / Q000379:methods*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000209:etiology / Q000473:pathology*; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013629:Tamoxifen / Q000627:therapeutic use
chemical_list: D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen