61 Background: There is limited information on LRR rates in pts treated with NAC.
METHODS
12 large NAC BC trials (11,955 pts) with pCR information and long-term F/U for LRR, EFS and OS were included. Primary aims were to assess LRR rates by pCR, tumor subtype, surgery type and other clinico-pathologic factors. Main definition of pCR was ypT0/is ypN0.
RESULTS
Median F/U: 5.4 years. Median age: 49, T2 tumors: 61%, Inflammatory BC: 4%; Clinically(+) nodes: 47%. Overall LRR: 6.8% (95% CI: 6.3, 7.2). LRR was 5.5% with pCR (ypT0/isypN0) vs. 7.1% without. After lumpectomy, LRR rates were similar with pCR (6.0%) vs. without (6.3%). After mastectomy, LRR rates were lower with pCR (3.8%) vs. without (8.1%), irrespective of XRT use. In HR(+)/HER2(-) BC, LRR rates were low with pCR (1.9%) or without (3.3%) with similarly low LRR rates in grade 1/2 tumors (pCR: 2%, no-pCR: 2.6%). In HR(+)/HER2(-)/grade 3 BC LRR rates were lower with pCR (1%) vs. without (5.3%). In HER2(+) BC LRR rates were similar with pCR (5.1%) or without (7.3%), mainly seen in HER2(+)/HR(+) BC (5.7% vs. 5.5%). In contrast, in HER2(+)/HR(-) BC LRR rates were lower with pCR (4.9%) vs. without (9.8%). Also, in HR(-) /HER2(-) BC LRR rates were lower with pCR (4.9%) vs. without (8.6%). LRR varied with path nodal status and TNM stage at surgery: node(-): 5.6% vs. node(+) 8.9%; stage 0: 5.3%; stage 1: 5.2%; stage 2: 7.3%; stage 3: 10.1%.
CONCLUSIONS
LRR rates after NAC are low and vary by pCR status, tumor subtype, type of surgery, stage and path nodal status. This information may have clinical implications on selecting appropriate candidates for XRT. [Table: see text].