Objective: In most muscle-invasive bladder cancer muscle invasion is present at the time of first diagnosis (primary tumours), in the rest of the patients muscle invasion is caused by progression of superficial tumours (progressive tumours). The aim of study is to determine whether a difference in natural history is between primary and progressive tumours. Material and methods: In 1997–2001 we treated 278 patients with bladder cancer, 167 (60.1%) patients had superficial tumours and 111 patients had invasive tumours. At the time of diagnosis muscle invasion of the bladder was present in 90 (81.1%) patients, in 21 (18.9%) invasion was formed by progression of superficial tumours. The retrospective study evaluated and compared characteristics of patients (incl. survival) and tumours. Statistical significance was calculated by the
2 test. Results: A mean age of patients with primary tumours was 65.2 ± 10.5 years, compared with mean age of 61.7 ± 12.6 years of patients with progressive tumours. Gender – male : female ratio was 3.1 : 1 in primary tumours, as opposed to 4.2 : 1 in progressive. Progression of superficial tumours was noted on average within 35.4 months (range of 7–115). Within one year died 46 out of 90 (51.1%) patients with primary tumours and 11 out of 21 (52.4%) patients with progressive tumours. Three years survived 14 out of 61 (23%) patients with primary tumours and two out of 13 (15.4%) with progressive tumours. Conclusions: Prognosis of patients with progressive tumours is worse than prognosis of patients with primary invasive tumours. It is vital to detect superficial tumours in their pre-invasive stage, when they can be treated successfully.

        Key words: bladder cancer – progression – prognosis