Also, a review of 106 patients with cautionary features (including estrogen receptor negativity) found that receptor

negativity was associated with a higher rate of IBTR (11.8% vs. 2.2%) (74). An analysis of high-risk patients including estrogen receptor–negative patients from the University of California Irvine also found that estrogen receptor negativity was associated with a decrease in recurrence-free survival (85). This has also been noted in older women who traditionally have excellent outcomes; Romidepsin in vitro analysis of the 537 women from the ASBS registry over age 70 years found that estrogen receptor–negative patients had higher rates of LR and decreased survival compared with estrogen receptor–positive patients (86). ABS Guideline: Estrogen receptor may be positive or negative. As noted previously,

there are increasing numbers of small series identifying higher rates of IBTR in estrogen receptor–negative patients undergoing APBI compared with estrogen receptor–positive patients undergoing APBI. Although these studies suggest that estrogen receptor negativity is associated with higher rates of local failure, similar findings have been seen with WBI and mastectomy and therefore may be indicative of the biology of an estrogen receptor–negative tumor and not the treatment modality [87], [88] and [89]. To date, there are no data comparing local outcomes in estrogen receptor–negative patients receiving mastectomy,

WBI, and APBI, and therefore, Cabozantinib clinical trial no data to suggest that rates of IBTR are higher in estrogen receptor–negative patients receiving APBI compared with those who receive WBI. Although margin status has been associated with IBTR in patients undergoing WBI after BCS, limited data are available for patients undergoing APBI (90). A recent analysis of the MammoSite Registry found that close and positive margins were associated with a trend for increased rates of IBTR (83). Furthermore, a series of 48 patients prospectively treated with multicatheter brachytherapy from Korea did find that recurrence was associated with patients with close surgical margins (<2 mm) (91). ABS Guideline: Surgical margins should be negative. Although limited, the evidence presented to date suggests that close/positive margins Pyruvate dehydrogenase lipoamide kinase isozyme 1 are associated with higher rates of IBTR in patients undergoing APBI. These findings are consistent with large studies of patients undergoing WBI, and as such, the guideline remains consistent with previous consensus statements and guidelines recommending negative surgical margins. Because of differences in pathologic assessment of surgical margins, a lack of consistent data identifying that a certain “ideal” margin exits, and the fact that NSABP continues to use a definition of “no tumor on ink,” the panel finds that the guideline should remain a negative margin.