Purpose: We investigated the effects of alterations in the biological markers p14, p53, p21, and p16 in relation to tumour cell proliferation, T-category, N- category, lymphovascular invasion, and the ability to predict prognosis in patients with muscle-invasive bladder cancer (MIBC) treated with cystectomy and, if applicable, chemotherapy.

Materials and methods: We prospectively studied patients with urinary bladder cancer pathological stage pT1 to pT4 treated with cystectomy, pelvic lymph node dissection and postoperative chemotherapy. Tissue microarrays from paraffin-embedded cystectomy tumour samples were examined for expression of immunostaining of p14, p53, p21, p16 and Ki-67 in relation to other clinical and pathological factors as well as cancer-specific survival.

Results: The median age of the 110 patients was 70 years (range 51-87 years), and 85 (77%) were male. Pathological staging was pT1 to pT2 (organ-confined) in 28 (25%) patients and pT3 to pT4 (non-organ-confined) in 82 (75%) patients. Lymph node metastases were found in 47 patients (43%). P14 expression was more common in tumours with higher T-stages (P = 0.05). The expression of p14 in p53 negative tumours was associated with a significantly shorter survival time (P=0.003). Independently of p53 expression, p14 expression was associated with an impaired response to chemotherapy (P=0.001). The expression of p21 in p53 negative tumours was associated with significantly decrease levels of tumour cell proliferation detected as Ki-67 expression (P=0.03).

Conclusions: The simultaneous expression of the senescence markers involved in the p53-pathway shows a more relevant correlation to the pathological outcome of MIBC than each protein separately. P14 expression in tumours with non-altered (p53-) tumours is associated with poor prognosis. P14 expression is associated with impaired response to chemotherapy. P21 expression is related to decreased tumour cell proliferation.