EXPRESSION OF THE TUMOR-ASSOCIATED ANTIGEN CA-242 IN TRANSITIONAL-CELL BLADDER-TUMORS - A COMPARISON WITH CA-50

The tissue expression of carbohydrate antigen CA-242 was analysed in f ormalin-fixed biopsy specimens from 147 transitional cell bladder tumo urs. The staining was related to established prognostic factors and su rvival during a mean follow-up of over 12 years and the staining resul ts were also compared to expression of CA-50 antigen. Forty-one percen t (60/147) of the tumours were negative for CA-242 and 59% (87/147) we re positive. Normal bladder mucosa was positive for. CA-242 and the um brella cells in particular showed intense positive staining. In tumour s, the umbrella cells were usually positive (when present) and in tumo ur tissue, positive cells appeared either as individual positive cells or in groups. None of the tumours was entirely positive for. CA-242. The tissue expression sf CA-242 could not be significantly related to TNM classification, papillary status, WHO grade or quantitative variab les (DNA ploidy, S phase fraction, mitotic frequency, nuclear factors) . The tissue expression of CA-242 was significantly weaker than the ex pression of CA-50. The expression of CA-242 was related to favourable prognosis in survival analysis (P = 0.04). The results show that the e xpression of the novel tumour marker antigen CA-242 as determined in p araffin-embedded material is a weak prognostic factor as compared with established prognostic factors in transitional cell bladder tumours.