A study of Swedish men with BPH found no excess risk of bladder cancer, but did show that the likelihood of the malignancy is elevated in those who undergo transurethral resection of the prostate (TURP), especially men with comorbid genitourinary tract conditions.
For 26 years, an international team followed 79,280 men hospitalized for BPH, identifying 506 new bladder cancer cases. The researchers calculated the standardized incidence ratio (SIR) for bladder cancer, that is, the ratio of the observed to the ex-pected number of new cases of bladder cancer.
There was no increased risk for bladder cancer in the overall study population. In the TURP-treated patients, however, the researchers observed an increased risk in all follow-up periods. The risk was 1.22, 1.32, and 1.47 for the 4-6, 7-9, and 10-26 year follow-up periods (years 0-3 were excluded).
For TURP-treated men with genitourinary comorbidities such as stones and infections, the SIRs were 1.72, 1.74, and 2.01, respectively. Moreover, among TURP-treated patients, only those first hospitalized before 1975 were at increased risk of bladder cancer.
The researchers noted that the study had a number of strengths, including a large sample size and a long follow-up. Limitations included incomplete adjustment for potential confounders due to lack of information on known risk factors for bladder cancer, such as smoking.
In addition, the researchers noted that “we used first date of hospitalization for BPH as a proxy for date of BPH diagnosis, although it is clear that the diagnosis and onset of BPH can take place before” that date.