Immunohistochemistry and c-kit gene analysis in determining malignancy in gastrointestinal stromal tumors.
ABSTRACT Usefulness of immunohistochemistry and c-kit proto-oncogene mutation was examined for determining malignancy in 24 cases of gastrointestinal stromal tumors.
Cases were histologically diagnosed and subjected to immunohistochemical staining and c-kit gene analysis. All parameters were compared to prognosis.
There were significant differences in tumor size, central necrosis, mitotic activity and histological diagnosis between recurrent and non-recurrent cases. Positivity to KIT staining was 100% in recurrent and 87.5% in non-recurrent cases. Positivity to Ki-67 and p53 staining were significantly higher in recurrent cases than in non-recurrent cases. Mutations in exon 11 of the c-kit gene were significantly more frequent in recurrent cases than in non-recurrent cases.
Histological diagnosis, tumor size, central necrosis, and mitotic activity were reconfirmed to be indicators for recurrence of gastrointestinal stromal tumors. Furthermore, it is suggested that positivity of Ki-67 and p53 immunostaining and c-kit gene mutation also need to be done for prediction of recurrence.