Analysis of gene mutation associated with tyrosine kinase inhibitor sensitivity of epidermal growth factor receptor in cervical cancer patients

OBJECTIVE: Cervical cancer is frequent in females. Epidermal growth factor receptor has a prominent expression in certain malignant tumors. This study aims to observe the expressional profile of epidermal growth factor receptor (EGFR) in cervical cancer patients, and mutation of EGFR gene related with its sensitivity towards tyrosine kinase inhibitor. MATERIALS AND METHODS: Cervical cancer patients from our hospital were recruited as the experimental group, in parallel with chronic cervicitis patients as control group. Serum EGFR level was measured by enzyme-linked immunosorbent assay (ELISA), and EGFR levels in cervical tissues were quantified by immunohistochemistry assay (IHC) staining. Real Time-PCR (RT-PCR) examined mutations of exon 18, 19, and 21 of the EGFR gene, to analyze their correlation with clinical or pathological features. RESULTS: Serum EGFR in experimental group was 1.16 +/- 0.04 ng/ml, significantly higher than control group (p < 0.05). EGFR positive rate was 71.1% in cancer tissues, significantly higher compared to controlled or adjacent tissues (p < 0.05). Mutation rats of EGFR exon 19 and exon 21 were 3.3% and 5%, respectively. No mutation was found in exon 18. Such mutations of EGFR gene were related with cancer differentiation grade, tumor-lymph-node-metastasis (TNM) stage, lymph node or distal metastasis (p < 0.05), but not age, Karnofsky performance score (KPS) score or infiltration depth. CONCLUSIONS: EGFR is highly expressed in serum and tumors of cervical cancer patients, some of which showed mutations of exon 19 and 21 of EGFR gene with relatively lower frequency. Mutation rates were significantly higher in patients with highly differentiated grade, early TNM stage, and those without lymph node or distal metastasis.