[Expression of the tumormarker p16INK4a in cytology specimens of the urinary bladder. A new means for early recognition and surveillance of urothelial cancer].

BACKGROUND

This study was carried out to learn whether cytological specimens from urinary bladder lavages express the tumor suppressor gene p16INK4a, whether an abnormally increased expression indicates a cancerous state and whether cytological measurements are comparable regarding sensitivity and specificity with measurements made in histological sections of biopsies.

PATIENTS AND METHODS

A total of 82 urine specimens of patients suspected of having a bladder tumor were examined for the presence of p16INK4a.

RESULTS

Out of 46 patients with urothelial carcinoma 29 expressed p16INK4a in the cells in the urine specimens. Out of 36 patients free of cancer 30 expressed no p16INK4a in cytological specimens. The sensitivity of the expression proved to be 63% and the specificity 83%. Well-differentiated carcinomas seldomly expressed an increased p16INK4a (sensitivity 27%), whereas moderately differentiated carcinomas showed a sensitivity of 69% and poorly differentiated carcinomas a sensitivity of 77%.

CONCLUSION

Compared to other minimally invasive tumor markers, such as NMP22, the expression of p16INK4a in cytology specimens of urine appears to be a sensitive marker for urothelial carcinoma, especially for the detection of poorly differentiated carcinomas. Its high specificity makes it ideal for use in tumor screening.