Immunohistochemical expression profiles of BRAF (V600E/VE1) in serrated colon polyps in Turkish population

Kokenek-Unal T. D., Senel F., Gurcay N., Tasdemir A., Coban I.

INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY, vol.10, no.8, pp.8868-8874, 2017 (SCI-Expanded) identifier identifier


Background and aim: Colon carcinoma, as one of the most common cancers, has been investigated for genetic alterations. Besides well-known adenoma-carcinoma sequence, it is recently found that BRAF mutation had an important role particularly in early stages of adenocarcinomas with serrated features. There are no any studies concerning immunohistochemical expression status of BRAF V600E (VE1) antibody in serrated polyps in the Turkish population. The objective of this study is to observe the immunohistochemical staining of BRAF V600E (VE1) antibody in colon polyps in the Turkish population and investigate the frequency of presence of mutated BRAF proteins indicating malignant potential. Materials and methods: 59 cases of serrated polyps (27 cases of hyperplastic polyps, 18 cases of sessile serrated adenoma/polyps and 14 cases of traditional serrated adenomas) and 10 tubular adenomas, and 10 samples of normal colonic mucosa were immunohistochemically evaluated for the presence of BRAF V600E mutated proteins with the VE1 antibody. Results were statistically compared. Results: All SSA/Ps; 92.8% of TSAs; 37% of HPs were stained positively. Of the 27 hyperplastic polyps, all GCHPs were negative but 10 of 12 MVHPs (83.3%) were weakly positive with the VE1 antibody. Cases in control groups and tubular adenomas didn't show any cytoplasmic staining. Conclusion: Serrated adenoma/polyps have been gaining much more importance because of their malignant potential. Their frequency is also relatively high in the Turkish population and they should be carefully handled. Detection of BRAF V600E status can be easily achieved immunohistochemically by VE1 antibody. It is easily applicable and reproducible method and it might be helpful in identifying serrated lesions of the colon in addition to morphological features.