Ipsilateral breast tumor relapse after breast conserving surgery in women with breast cancer.

Ipsilateral breast tumor relapse (IBTR) is a potentially a significant problem after breast conserving surgery (BCS). With a median follow-up period of 64.7 months, IBTR occurred as a first relapse in 67 (3.0%) of a total of 2243 patients and distant recurrence occurred in 167 (7.4%). A positive surgical margin and the omission of radiotherapy (RT) were independently associated with IBTR. The five-year cumulative IBTR rates were 5.1% in patients with positive margins and 2.0% in the patients with negative margins. The five-year cumulative IBTR rates were 1.8% in patients with RT and 8.1% in patients without RT. IBTR was independently associated with distant-recurrence-free survival rates as well as age, nodal metastasis, lymphovascular invasion and progesterone receptor status. The five-year distant-recurrence-free survival rates were 81.9% in patients with IBTR and 93.2% in patients without IBTR. In order to prevent IBTR, a negative margin and the administration of RT are therefore considered to be important in patients who undergo BCS.