Hospital and surgeon caseload are associated with risk of re-operation following breast-conserving surgery

Breast-conserving surgery (BCS) is increasingly used for breast cancer treatment. One of the disadvantages of BCS is the risk of re-operation, associated with additional costs to the woman, health service and society. Hospital and surgeon caseload have been associated with better outcomes in breast cancer. Whether these are related to re-operation rates is not clear. In women who underwent BCS initially, we aimed to quantify re-operation rates and identify the factors related to the risk of undergoing subsequent (i) re-operation and (ii) total mastectomy (TM). From the National Cancer Registry Ireland, we identified women diagnosed with a first invasive breast cancer during 2002-2008, and who initially had BCS. Poisson regression with robust error variance was used to identify factors significantly associated with (i) re-operation (vs no re-operation) or (ii) re-operation by TM (vs re-operation by BCS). 16,551 women were diagnosed with invasive breast cancer and 8,318 underwent initial BCS. Of these, 17 % had one or more subsequent re-operations and, of these, 62 % had TM. Surgeon and hospital volume significantly predicted subsequent re-operation after adjustment for socio-demographic and clinical variables. Women having surgery in lower-volume hospitals by low-volume surgeons significantly increased the risk of re-operation [incidence rate ratio (IRR) = 1.56; 95 % CI 1.33-1.83] compared to those operated in higher-volume hospitals by a higher-volume surgeon. Risk of subsequent TM was increased by 22 % (95 % CI 1.10-1.35) and 21 % (95 % CI 1.09-1.33), if women were operated by a lower or intermediate-volume surgeon. The fact that factors related to healthcare organisation/service provision are associated with re-operations suggests that it may be possible to reduce the overall re-operation rate. The high frequency of subsequent TM raises questions about strategies for selecting women for initial BCS. Our results may inform the development of information strategies to help ensure that women are aware of risks of re-operation following BCS and hence, make appropriate treatment choices.