[Immunohistochemical investigation of proliferating cell nuclear antigen in bladder cancer]

Proliferating cell nuclear antigen (PCNA) of formalin-fixed, paraffin-embedded bladder cancer section was identified by immunohistochemistry in 42 bladder cancer patients. In 29 (69%) patients, the cancer cells showed a strong immunoreactivity for PCNA. An increase in the labeling index for PCNA (PCNA-LI) was significantly correlated with a higher clinical stage (p < 0.05) and pathological grade (p < 0.05). However, there was no significant correlation between PCNA-LI and the recurrence rate of superficial bladder cancer. The relationship between changes of PCNA-LI after neoadjuvant chemoradiotherapy and prognosis was investigated in 20 patients with invasive bladder cancer. Patients with a decreased PCNA-LI after chemoradiotherapy had a better prognosis than those with a stable or increased PCNA-LI. The 5-year cause-specific survival rate of the patients with a decreased PCNA-LI after treatment was 86%, while that with a stable or increased PCNA-LI was 30% (p < 0.01). This finding suggests that changes of PCNA-LI could be a new parameter for the histological evaluation of chemoradiotherapy.