Ipsilateral breast recurrence after breast conserving surgery in patients with small (≤2 cm) breast cancer treated with modern adjuvant therapies

Background: Modern multimodality treatment greatly influences the rate and the predictive factors for ipsilateral cancer recurrence (IBR) after breast conserving surgery. Material and methods: The study is based on 1297 patients with pT1 breast cancer and treated with breast conserving surgery in February 2001-August 2005. The median duration of follow-up was 57 months. Results: IBR occurred in 27 (2.1%) patients. It was located in the quadrant of prior breast resection in 17 (63%) cases. The median time to an IBR was 41 months (range, 6-78) regardless of whether the recurrence was located in the same or in another quadrant. Omission of radiotherapy was associated with a higher IBR incidence, HR 10,344 (95% CI 1904-56,184; p = 0.007). The IBRs occurred particularly often, in 27% of the 11 patients who refused radiotherapy. Patients diagnosed with ER+ cancer had a lower risk of IBR when compared with those with ER-/HER2+ cancer, HR 0.215 (95% CI 0.049-0.935; p = 0.040). Conclusions: The risk of IBR was low during the first 5 years after breast resection among patients with pT1 breast cancer and treated with modern surgical and adjuvant therapies. The majority IBRs still occur at or close to the prior resection site underlining the importance of local therapies. Omission of radiotherapy was the most significant risk factor for IBR. (C) 2010 Elsevier Ltd. All rights reserved.