Locoregional recurrence

the importance of free surgical margins and molecular subtypes of breast cancer

Abstract

The equivalent survival rates observed between breast-conserving surgery and mastectomy for breast-conserving surgery made the first the standard treatment for many women with breast cancer and it is preferable to mastectomy because of the aesthetic benefit of preserving the breast. Conservative surgery supplemented by radiotherapy has high levels of local control of disease. The size of the tumor margin is appropriate subject of interest due to the tendency of less radical surgery, while maintaining oncological safety. It is also important in relation to mastectomy due to the possibility of preserving the skin and nipple-areola complex which may mean lower margins. Several studies suggest that an adequate excision with margins free of tumor is required to obtain an optimal local control. However, the very concept of what are free surgical margins is controversial and it is highly questionable whether the increased size of free surgical margins results in decreased risk of local recurrence. More extensive resections are associated with lower local recurrence but available data suggest that the increase in millimeter of free margin does not result in a proportional reduction in risk of recurrence. Currently, the surgical treatment considered appropriate is the one that can obtain a negative surgical margin regardless of their size. Several pathological factors and different clinical treatments have also been associated with increased risk of local recurrence, including the dose of radiation, which is the definition of the positive and negative edge. Other factors also associated are the extent of involvement of the edge, the presence of extensive intraductal component, time tracking of patients, the influence of adjuvant systemic therapy and, with great interest at present, molecular genetic subtypes of breast cancer – luminal A, luminal B, Her-2 positive and triple negative. The identification of risk factors for local recurrence among patients with negative margins is very important and a challenge for the clinical outcome of breast cancer. This article reviewed the studies related to what is considered adequate surgical margin and the influence of molecular subtypes to identify the risk of locoregional recurrence as well as its impact on therapeutic decision making, meeting the current tendency to individualize treatment based on several factors related to recurrence of breast cancer.