EGFR gene mutation in gastrointestinal stromal tumors

Abstract

Aims

The aim of this study was to evaluate the mutation status of EGFR in gastrointestinal stromal tumours and its association with various clinicopathological variables as well as to further discuss its effects of EGFR mutations on tumor formation and progression.

Methods

A well-characterized cohort of 323 GISTs, obtained between 2010 and 2015 from the surgical pathology files of at the Department of Pathology of the Nanjing Jinling Hospital, was screened for mutations in exon 19 and 21 of the EGFR gene. Patient clinical data and clinicopathological features were collected if available in the medical records.

Results

Among the 323 primary GISTs, we identified 3 cases (0.93%) of EGFR mutations; these mutations never occurred together with KIT, PDGFRa, KRAS, or BRAF gene mutations. In 2 cases, tumors cells exhibited spindle cell morphology, and in one case, epitheliumal cell morphology. Additionally, the morphology and immunophenotype of these 3 cases did not show significant differences compared to common GISTs. The clinical results summarized that 2 cases of EGFR-mutated GISTs occured in females and in the stomach. The mean age of EGFR-mutated cases were 54.33 years, and the follow-up datas indicated that these tumors were low risk and exhibited low recurrence.

Conclusions

We firstly established that GISTs carrying EGFR mutation are relatively benign tumors. Althought EGFR mutation were rarely present in GIST, EGFR seems to play a significant role in the development and progression of GIST.

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