Molecular genetic and morphological features of malignant neoplasms of the stomach and colon with tissue eosinophilia

Aim. To study molecular genetic and morphological features of neoplasms in stomach and colon cancer associated with tissue eosinophilia. Methods. Study material was the tissue samples of malignant neoplasms of the stomach and colon obtained from the surgical procedures. Study groups were identified depending on the presence or absence of eosinophilic infiltration of the tumour tissue as well as on neoplasm localization. Medical records and outpatient patient cards were analyzed, presence of matastases in regional lymph nodes and grade of differentiation of malignant cells were evaluated. In tumour tissue expression of p53 and p21 proteins was evaluated by means of immunohistochemical technique. To study the distribution of polymorphic variants of р53 (G215C) and р21 (A1026G) genes, deoxyribonucleic acid extraction was performed from formalin-fixed and paraffin-embedded tissue samples obtained from the resection margins. Polymorphism genotyping of deoxyribonucleic acid samples was performed by restriction fragment length polymorphism analysis of amplification products with the use of polymerase chain reaction of specific genome regions with further visualization with ultraviolet light. Results. In patients with colon cancer associated with tissue eosinophilia tumour cells were shown to have higher grade of differentiation than in patients without eosinophilia. In stomach cancer associated with eosinophilic infiltration low expression of mutant p53 protein was revealed significantly more frequently as opposed to cancer without eosinophilia. Also in patients with stomach and colon cancer, association of tissue eosinophilia with carriage of G allele of р53 (G215C) gene polymorphism was found. Conclusion. Tissue eosinophilia in stomach and colon cancer is associated with favourable morphological cancer characteristics, low expression of mutant p53 protein and carriage of G allele of р53 (G215C) polymorphism.