Inconsistent radiotherapy effects between primary tumors and axillarylymphnodes

Negative surgical margins are important for patients treated with breast-conserving therapy(BCT)BCT has been a standard practice in breast cancer treatment for more than 2 decades.For patients who receive BCT,a positive surgical margin is defined by the presence of ink at the surfaces of surgical specimens,in either the invasive tumor cells or breast ductal carcinoma in sit,thus implying potentially incomplete resection,which is associated with a significantly elevated risk of ipsilateral breast tumor recurrence(IBTR)1,2.A meta-analysis with a median follow-up of 6.6 years has reported an odds ratio(OR)of 1.96[95%confidence interval(CI):1.72-2.24]for IBTR in patients with positive rather than negative surgical margins(no ink on the tumors).