Prostate cancer patients treated with radiotherapy have a higher risk of developing and dying from bladder cancer or lung cancer than patients treated with radical prostatectomy alone, according to a study published in European Urology Focus.
The increased risks of bladder and lung cancer were seen regardless of whether the radiotherapy was brachytherapy or external beam radiation therapy (EBRT).
For this study, researchers used SEER-17 data to compare rates of secondary malignancy and related deaths in patients with prostate cancer who were treated with radical prostatectomy, EBRT, brachytherapy, EBRT plus brachytherapy, or radical prostatectomy followed by EBRT during 2000-2019.
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An age-matched subset of 261,609 patients was used as the final cohort. The median age was 64 years in all treatment groups. At a median follow-up of 11.6 years, 4876 patients had a bladder cancer diagnosis, and 6891 had a lung cancer diagnosis.
When compared to patients who received radical prostatectomy alone, patients who received all other treatments had an increased risk of bladder cancer and lung cancer. Patients who received EBRT, brachytherapy, or EBRT plus brachytherapy had an increased risk of death from lung cancer or bladder cancer, as seen in the table below.
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Hazard Ratios for Cancer Diagnosis and Death |
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|
Bladder Cancer Diagnosis |
Bladder Cancer Death |
Lung Cancer Diagnosis |
Lung Cancer Death |
|
Radical prostatectomy |
Reference |
Reference |
Reference |
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|
EBRT |
1.72; 95% CI, 1.61-1.85; P <.001 |
2.39; 95% CI, 1.92-2.96; P <.001 |
1.63; 95% CI, 1.54-1.73; P <.0001 |
1.73; 95% CI, 1.61-1.87; P <.001 |
|
Brachytherapy |
1.85; 95% CI, 1.71-2.00; P <.001 |
2.57; 95% CI, 2.04-3.25; P <.001 |
1.32; 95% CI, 1.23-1.42; P <.0001 |
1.36; 95% CI, 1.24-1.49; P <.001 |
|
EBRT plus brachytherapy |
1.80; 95% CI, 1.63-2.00; P <.001 |
3.02; 95% CI, 2.31-3.96; P <.001 |
1.42; 95% CI, 1.30-1.55; P <.0001 |
1.38; 95% CI, 1.22-1.55; P <.001 |
|
Radical prostatectomy followed by EBRT |
1.53; 95% CI, 1.28-1.82; P <.001 |
1.43; 95% CI, 0.75-2.70; P =.28 |
1.30; 95% CI, 1.12-1.51; P <.001 |
1.08; 95% CI, 0.87-1.35; P =.47 |
The researchers noted that the hazard ratios for lung cancer diagnosis and death were lower than the hazard ratios for bladder cancer diagnosis and death.
“This suggests that patient comorbidities and smoking status, which is highly associated with both lung and bladder cancer, were not exclusively driving the bladder cancer HRs [hazard ratios] in this study,” the researchers wrote.
The team also noted that the observed incidence of bladder cancer 10 years after radiation was about twice the incidence in patients who had radical prostatectomy (0.35 and 0.15 per 100 person-years, respectively).
“This is a small absolute rate, and with these numbers, 500 person years of radiation versus RP [radical prostatectomy] would be needed to observe one additional case of bladder cancer,” the researchers wrote. “For older patients, this is likely not clinically significant. For younger men with longer life expectancies, however, this increased risk of bladder cancer may factor into initial treatment decisions for prostate cancer.”
Reference
Monda S, Pratsinis M, Lui H, et al. Secondary bladder cancer after prostate cancer treatment: An age-matched comparison between radiation and surgery. Eur Urol Focus. Published online September 16, 2023. doi:10.1016/j.euf.2023.09.002
This article originally appeared on Cancer Therapy Advisor