EVALUATION OF THE PROGNOSTIC VALUE OF THE EXPRESSION OF EPIDERMAL GROWTH FACTOR RECEPTORS IN BLADDER CANCER

Abstract

Objectives

To evaluate the role and prognostic value of the expression of epidermal growth factor receptors (EGFR) in serum and urine for the detection of human bladder cancer.

Patients and Methods

The study comprised 30 patients with newly diagnosed transitional cell carcinoma of the bladder and 10 normal volunteers. The patients' age ranged from 42 to 76 years. The serum and urinary EGFR levels were evaluated using the ELISA technique. An indirect haemoagglutination (IHA) test was used for the detection of bilharzial antibodies. Cystoscopy, tumor resection and bimanual examination under anaesthesia were carried out for every patient. The patients were divided into 4 groups: Group A: 10 healthy individuals serving as a control group, Group B: 7 patients with grade I bladder cancer, Group C: 10 patients with grade II bladder cancer and Group D: 13 patients with grade III bladder cancer.

Results

Bilharziasis was recorded in 33 patients, 6 of them were in the control group. A comparison between the bilharzial and non-bilharzial patients did not reveal any significant difference in the serum EGFR expression (46.47 ± 32.23 and 36 ± 38.22 fmol/ml, respectively) nor in the urinary EGFR expression (45.42 ± 29.78 and 41 ± 31.16 fmol/ml, respectively). None of the patients with grade I bladder cancer was found to have stage T3 and T4 cancer, while all the patient with grade II and grade III cancer had invasive cancer (> Ta). The mean values of urinary and serum levels of EGFR in the control group were 12.37 ± 7.21 and 11.9 ± 8.17 fmol/ml, respectively, while the mean values of urinary and serum levels of EGFR in the cancer patients were 46.47 ± 32.23 fmol/ml and 45.4 ± 29.78 fmol/ml, respectively, which represents a significant increase in the serum and urinary EGFR in the cancer patients as compared to the control goup. In addition, a stepwise increase in the serum and urinary EGFR was noted with the cancer grade increasing from grade I to III. The best cut-off values for serum and urinary EGFR were 22 fmol/ml and 25 fmol/ml, respectively. The best cut-off point for the serum EGFR level had a sensitivity of 83.3%, a specificity of 90% and an accuracy of 85%, while the best cut-off point for the urinary EGFR level had a sensitivity of 80%, a specificity of 90% and an accuracy of 82.5%.

Conclusion

Resultsof the present study suggest that high levels of EGFR in the serum and urine of patients with bladder cancer are related to various malignant histological features (tumor grade) and invasiveness of bladder cancer. In the future, the evaluation of urinary and serum EGFR might help in the prediction of recurrence rate, response to systemic treatment and in the screening of bladder tumors.

African Journal of Urology Vol. 7 No. 1 (Jan 2001): pp 20-26

Key Words

bladder cancer, epidermal growth factor receptors, tumors markers