A study done in Denmark has investigated the link between human epidermal growth factor receptor 2 amplification and the different types of gene signal distribution in gastroesophageal cancer.
Amplification of the human epidermal growth factor receptor 2 (HER2) gene and over expression of the HER2 protein is found in a number of human cancers including breast and gastroesophageal cancer. HER2 forms both homo- and heterodimers with the different members of the HER family, thereby serving as a critical dimerization partner, which leads to activation of downstream signalling pathways associated with cell proliferation, differentiation, survival and angiogenesis. Differences in HER2 gene signal distribution patterns can be observed at the tissue level, but how it influences the HER2 amplification status has not been studied so far.
A study led by Jan Trøst Jørgensen at the Dx-Rx Institute analyzed tumour samples from 140 patients with gastroesophageal adenocarcinoma using the HER2 IQFISH pharmDx™ assay. Researchers found that among the 140 analyzed specimens, 83 had a heterogeneous HER2 signal distribution, with 62 being focal and 21 of the mosaic type. The remaining 57 specimens had a homogeneous signal distribution. Furthermore, HER2 amplification was observed in 63 of the 140 specimens, and nearly all were found among specimens with a heterogeneous focal signal distribution.
The results from this study suggest that a clear relationship between HER2 amplification and the focal heterogeneous signal distribution was demonstrated in tumour specimens from patients with gastroesophageal cancer. Further research needs to be done to determine if and how the HER2 signal distribution patterns play a role in cancer development.