Positive HER2 Immunoreactivity in DCIS Is Associated with a Higher Incidence of Invasive Disease, Particularly in the Subsequent Resection in a Group of Patients without Radiographic Evidence of Invasion Disease
S Harada, R Roses, HL Niu, S Weinstern, H Nisenbaum, KR Fox, BJ Czerniecki, PJ Zhang. Hospital of the University of Pennsylvania, Philadelphia; Hospital of the University of Pennsylvania
Background: Prognostic significance of ER, PR and HER2 phenotype has been established in invasive carcinoma. The implication of these phenotypic patterns in DCIS remains uncertain. This study is to determine whether DCIS ER/PR/HER2 phenotypes have any role in progression to or association with invasive cancer in DCIS.
Design: Clinical and histologic materials of 104 patients, whose DCIS were tested for ER, PR and HER2, were reviewed. No invasive disease was suspected in radiographic evaluation. All patients underwent biopsy and subsequent resection. The HER2 status was determined by HercepTest and considered positive when 2+ >10% was detected. The rate of invasive disease was evaluated in relation to various histopathologic features of DCIS as well as their ER/PR/HER2 status.
Results: Invasive disease was identified histologically in 23 patients (22%), 3 in initial biopsy (size 1-2 mm each) and 20 more in the subsequent resection (size 1-15 mm, mean 45 mm). The phenotype of all DCIS and those with invasive disease are summarized in Table 1. HER2 positive DCIS (HER2+ and luminal B) have significantly higher rate of invasive disease than HER2 negative DCIS (15/36, 42% vs. 8/68, 12%; p=0.002). The rates of invasion associated with luminal B (50%) and HER2+ phenotypes (36%) were significantly higher than that associated with the luminal A DCIS (11%) (p<0.001 and p=0.005, respectively).
|Table 1||Lumnal A||Her2+||Luminal B||Basal|
|DCIS||62/104 (60%)||22/104 (21%)||14 (3%)||6 (6%)|
|Invasive disease||7/62 (11%)||8/22 (36%)||7/14 (50%)||1/6 (17%)|
Conclusions: Invasive disease was identified in 22% of the patients who had DCIS and no radiographic evidence of invasive disease. Majority of these invasive lesions were associated with HER2+ DCIS, and were small (mean <5 mm) with only 13% of them detectable in the initial biopsy. These observations suggest a possible role of HER2 in the progression of in-situ to invasion. HER2 test might predict a group of DCIS with higher risk of invasive lesion in resection sepcimen. Therapies targeting HER2 may be used in cancer prevention in patients with DCIS.
Monday, March 9, 2009 9:30 AM
Poster Session I Stowell-Orbison/Autopsy Award # 34, Monday Morning