HER2 expression in oesophageal carcinoma and Barrett's oesophagus associated adenocarcinoma: An Australian study

Several studies have evaluated the prognostic value of HER2 in oesophageal cancer, but the prognostic influence of HER2 overexpression in oesophageal cancer remains uncertain. The aim of this study was to assess the incidence of HER2 positivity and relationship with clinicopathological features in patients with oesophageal cancer.

The study cohort consisted of 269 patients diagnosed with oesophageal carcinoma in a single institution. HER2 expression was analysed by immunohistochemistry (IHC) and silver in situ hybridization (SISH) in 152 archival oesophageal cancer specimens. Survival analysis was assessed using Hazard models.

HER2 expression was IHC3+ in 14 (9.2%), IHC2+ in 14 (9.2%), IHC1+ in 57 (37.5%), and IHC0 in 67 (44.1%) cases. SISH results confirmed that 15 specimens (9.9%) were HER2 gene amplified. Among 27 squamous cell carcinomas (SCCs) only 3.7% were HER2 positive whereas 11.2% of 125 adenocarcinomas were HER2 positive. The HER2 positive tumours were more likely to occur in men (OR: 5.00, 95% CI: 1.69-14.29), smokers (OR: 10.00, 95% CI: 4.17-25) and in patients with Barrett's oesophagus (OR: 8.33, 95% CI: 3.71-20.00). There was no significant difference in survival between the (HER2 +ve, 14.3 months vs HER2 -ve, 24.6 months, p = 0.42) CONCLUSION: A HER2 prevalence rate of 9.9% was found among patients with oesophageal cancer and no correlation with survival was detected overall.