The relationship between HER-2 and TOPO-2A gene expression and clinicopathologic results in gastric cancer.

e14670 Background: HER-2 and Topo-2A genes are settled on a chromosome 17 and their co-amplification rates are high. In this study, early gastric cancer patients who received adjuvant chemo-radiotherapy and chemotherapy were evaluated with HER-2 and Topo-2A expression in association with clinical and histopathologic findings. Methods: A total of 103 gastric cancer patients were included the study. The HER-2 and Topo-2A levels were measured by immunohistochemistry in postoperative tumor materials. A standard evaluation method was admitted for HER-2 positivity, while Topo-2A nuclear staining 3+ and 4+ were considered as overexpression. Those with level 2+ or 3+ of HER-2, the FISH test were attempted. Results: The median follow-up was 19 months (ranges 2–70 months). Forty-six patients (44%) relapsed during follow-up whereas 60 patients (58%) had died. The median overall survival (mOS) was 23 months. Histopathologies of HER-2 positive patients were intestinal type in 7 (87.5%) and diffuse type in one (12.5%) patient. In the follow-up period 4 patients (50%) were died (mOS was 17 months in this group). Median overall survival was 23 months in HER-2 negative group (p=0.6). Histopathologies of Topo-2A positive patients were intestinal type in 9 (64.2%) and diffuse type in 5 (35.8%) patient. In the follow-up period 8 patients (57%) were died (mOS was 22 months in this group). Median overall survival was 23 months in Topo-2A negative group (p=0.8). Three patients (37.5%) who had HER-2 positive histopathologies also had Topo-2A positivity. Conclusions: Overexpression rates of HER-2 in gastric cancer were reported 6.8-34%. Racial differences and different scoring techniques thought to be impact the results. Co-amplification rate of HER-2 and Topo-2A was reported 34% in gastric cancer. In our study HER-2 and Topo-2A overexpression rates were 7.7% and 13.6% respectively and co-amplification of HER-2 with Topo-2A rate was 37.5% is also similar to the other studies. Stages of patients with HER-2 and Topo-2A overexpression were similar to the distribution of the overall patients. While intestinal subtypes showed a higher rate of HER-2 overexpression, the median survival times tend to be shorter in HER-2 positive patients.