Subsets of women with close or positive margins after breast-conserving surgery with high local recurrence risk despite breast plus boost radiotherapy.

(1) To examine the effect of surgical margin status on local recurrence (LR) and survival following breast-conserving therapy; (2) To identify subsets with close or positive margins with high LR risk despite whole breast radiotherapy (RT) plus boost. Subjects were 2,264 women with pT1-3, any N, M0 invasive breast cancer, treated with breast-conserving surgery and whole breast ± boost RT. Five-year Kaplan-Meier (KM) LR, breast cancer-specific and overall survival (BCSS and OS) were compared between cohorts with negative (n = 1,980), close (n = 222), and positive (n = 62) margins. LR rates were analyzed according to clinicopathologic characteristics. Multivariable Cox regression modeling and matched analysis of close/positive margin cases and negative margin controls were performed. Median follow-up was 5.2 years. Boost RT was used in 92% of patients with close or positive margins. Five-year KM LR rates in the negative, close and positive margin cohorts were 1.3%, 4.0%, and 5.2%, respectively (p = 0.001). BCSS and OS were similar in the three margin subgroups. In the close/positive margin cohort, LR rates were 10.2% with age <45 years, 11.8% with Grade III, 11.3% with lymphovascular invasion (LVI), and 26.3% with ≥4 positive nodes. Corresponding rates in the negative margin cohort were 2.3%, 2.4%, 1.0%, and 2.4%, respectively. On Cox regression analysis of the entire cohort, close or positive margin, Grade III histology, ≥4 positive nodes, and lack of systemic therapy were significantly associated with higher LR risk. When close/positive margin cases were matched to negative margin controls, the difference in 5-year LR remained significant (4.25% vs. 0.7%, p < 0.001). On univariable analysis, subsets with close or positive margins, in combination with age <45 years, Grade III, LVI, and ≥4 positive nodes, have 5-year LR >10% despite whole breast plus boost RT. These patients should be considered for more definitive surgery.

Lupe K ，Truong PT ，Alexander C ，Lesperance M ，Speers C ，Tyldesley S ... -  《-》

Patients with t1 to t2 breast cancer with one to three positive nodes have higher local and regional recurrence risks compared with node-negative patients after breast-conserving surgery and whole-breast radiotherapy.

Truong PT ，Jones SO ，Kader HA ，Wai ES ，Speers CH ，Alexander AS ，Olivotto IA ... -  《-》

A positive margin is not always an indication for radiotherapy after mastectomy in early breast cancer.

Truong PT ，Olivotto IA ，Speers CH ，Wai ES ，Berthelet E ，Kader HA ... -  《INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS》

Selecting breast cancer patients with T1-T2 tumors and one to three positive axillary nodes at high postmastectomy locoregional recurrence risk for adjuvant radiotherapy.

Truong PT ，Olivotto IA ，Kader HA ，Panades M ，Speers CH ，Berthelet E ... -  《INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS》

Negative margin status improves local control in conservatively managed breast cancer patients.

Obedian E ，Haffty BG 《-》