Predictive value of p53 and NAT2 enzyme for disease free survival in patients with superficial bladder cancer

Abstract

Considering the higher recurrence rates in superficial bladder cancer, p53 immunoreactivity together with functional differences of N-acetytransferase-2 (NAT2) enzymes were studied to evaluate their overall effects on disease free survival rates (DFS) in 45 patients with superficial bladder cancer. Between 1994 and 2001, 45 patients with bladder cancer have been evaluated. All patients underwent transurethral resection of the tumor with or without intracavitary treatment. During follow-up period, ranging from 7 to 122 months (mean 27.3) DFS rates were comparatively evaluated with p53 immunoreactivity in tissue specimens obtained together with the functional differences of NAT2 assessed serologically. lmmunohistochemical (IHC) study was used to evaluate p53 immunoreactivity. NAT2 alleles were differentiated by polymerase chain reaction using the restriction fragment length polymorphism (PCR-RFLP). According to our results, the overall p53 immunoreactivity was 35.5%. As a sole parameter, p53 immunoreactivity of bladder cancer did not affect DFS (p>0.05). P53 immunoreactivity classified with tumor grade according to WHO criteria were as follows; 29% of low malignant potential, 38% of low-grade cancer and 29% of high grade of cancer. Tumor grade in p53 (+) patients was the only parameter showing differences in the DFS in low grade bladder cancer (p<0.05). According to functionally different subtypes of NAT2; slow type NAT2 were 55% (n: 25) and rapid type NAT2 were 45% (n: 20). Patients showing p53 negativity and rapid subtype of NAT2 enzyme exhibited approximately two fold differences in DFS. In our present study, although the patient number was limited, we were able to show long-term DFS in case of rapid type NAT2 and p53 negativity. P53 positivity and slow type NAT2 might be accepted as a bad prognostic factor for DFS in superficial bladder cancers.