Relationship of HER2 overexpression to brain metastasis (BM) in esophageal cancer (EC) patients.

Abstract

e14572 Background: BM is historically an uncommon relapse pattern of EC. HER2 is a membrane tyrosine kinase that is overexpressed in various cancers as EC and breast cancer (BC). BM in BC patients has been linked to HER2 overexpression, but HER2 status was not explored in EC patients who experience BM. Methods: We retrospectively reviewed the medical records of EC patients who underwent esophagectomy at University of Iowa Hospitals and Clinics between 2000 and 2010. Data analyzed consisted of demographic and clinical variables including tumor stage, grade, histology, neoadjuvant chemoradiation (NCR), tumor response to NCR and first site of cancer relapse. We stained the brain metastasis tissue for HER2 overexpression using Dako Hercept immunohistochemistry (IHC) test per the FDA approved kit guidelines Results: 142 patients were reviewed; 124 males and 18 females. Median age: 64 years (36-86). 88 patients (62%) received NCR. In the NCR group, complete and partial responses (CR and PR) were achieved in 17 (19%) and 71 (81%) patients, respectively. Median follow-up for relapse was 9.2 months and median survival was 32.9 months (95% CI: 24.2-41.6 months). Thirty two percent (28/88) patients had cancer relapse. The brain was the first site of relapse in 7/28 patients (25%; 95% CI: 10.7%-44.9%). Patients with BM had the following characteristics: cancer stage was T3N1 (7/7), NCR (7/7), CR (1/7), PR (6/7), adenocarcinoma (5/7), Squamous cell carcinoma (2/7), poor differentiation (5/7). IHC staining for HER2 was done on 6/7 BM specimens. 3/6 (50%) specimens showed 3+ staining. The rest of the specimens (3/6) were negative (0 staining). Conclusions: HER2 overexpression might be associated with increased risk of BM in EC patients following esophagectomy. This finding is consistent with the BC literature showing increased risk of BM in patients who overexpress HER2. A larger cohort of EC patients will be required to validate this observation.