Ipsilateral breast tumor recurrence: is there any evidence for benefit of further systemic therapy?

To date, there are no standard guidelines for treating patients with ipsilateral breast tumor recurrence (IBTR). Current practice is to resect the recurrence with a radical intent followed possibly by radiotherapy if the patient has not received this before, but the role of further adjuvant medical (hormone or chemotherapy) therapy remains undefined. Currently Phase III trials are underway to answer this question. In this review, we will focus on published data relating to IBTR and discuss recent trials. The results from the Phase III trials will not be available for sometime. At the time of IBTR, it is reasonable to change the endocrine therapy with indirect evidence from sequencing of impact on outcome. There is currently no conclusive evidence to suggest that further adjuvant chemotherapy post loco-regional recurrence impacts on survival, though the use of noncross-resistant chemotherapy drugs may make sense in those at highest risk. Biopsy at IBTR is helpful to distinguish whether it is a true recurrence or a new primary tumor and receptor phenotyping may be helpful for HER2. Future trials in IBTR need to address the following issues: to be able to distinguish between true recurrence and new primary (consensus required on definitions); pathologic processing relating to margins needs to be standardized (1 or 5 mm wide specimens); documentation of the pattern of IBTR in relation to each histopathologic subtype and methods used for pathologic examination by centers. Regional nodal recurrence including supraclavicular node recurrence is not dealt with in this review.