Impact of previous radiotherapy for prostate cancer on clinical outcomes of patients with bladder cancer

Abstract

Purpose: The impact of prostate cancer radiotherapy on the biological behavior of bladder cancer remains unclear. We compared the outcomes of patients with bladder cancer previously treated for prostate cancer with radiotherapy vs other treatment modalities.

Materials and methods: We identified 144 patients diagnosed with bladder cancer between January 1992 and June 2007 with a previous prostate cancer diagnosis. Clinicopathological data and outcomes were compared between patients with irradiated (brachytherapy and/or external beam radiation therapy 83) and nonirradiated (androgen deprivation therapy, radical prostatectomy and/or surveillance 61) disease.

Results: Median time between prostate and bladder cancer diagnoses was longer in the irradiated vs nonirradiated group (59 months, IQR 25 to 88, vs 24 months, IQR 2 to 87, p = 0.007). Patients in the irradiated group presented with higher tumor grade (high 92% vs 77%, p = 0.016) and had progression to higher stage disease (muscle invasive 70% vs 43%, p = 0.001) than those in the nonirradiated group. Of the patients undergoing cystectomy those previously treated with radiation had a numerically higher rate of nonorgan confined disease (75% vs 56% for nonirradiated, p = 0.1). Among all patients with bladder cancer 5-year cancer specific survival was 73% (95% CI 59-87) for irradiated vs 83% (95% CI 71-95) for nonirradiated (p = 0.07). Median followup was 53 months (IQR 24 to 75).

Conclusions: More time elapsed between prostate and bladder cancer diagnoses for patients treated with radiation, and these patients also presented with more advanced disease. Future studies are needed to further establish clinical differences in bladder cancer between irradiated and nonirradiated cases, and whether biological differences exist.

Figure 1

Probability of cancer-specific survival among nonirradiated (blue) and irradiated (green) bladder cancer patients.