Sperling Prostate Center

Radiation for Prostate Cancer and Risk for Bladder Cancer

UPDATE: 10/26/2021
Originally published 10/16/2016

It was bad news then, and five years down the road it’s still bad news. According to Barnett, et al. (2021), “Of the risks associated with RT, the development of a secondary malignancy is of most concern for the patient and physician.”[i] The blog we posted below presented a 2016 paper on prostate cancer (PCa) radiation therapy (RT) as a catalyst for secondary bladder cancer (BLCa). More than two years later, Renal & Urology News ran a story about a 35% higher risk for developing BLCa after RT vs. radical prostatectomy (RP). The sobering article drew up a 2018 analysis by Moschini, et al.[ii] that was based on 84,397 PCa patients. 51,145 had RT while 33,252 had RP, and follow-up was an average 69 months. Based on follow-up at 5 years, the Moschini study concluded, “Patients treated with EBRT are at increased risk of developing a second primary BCa compared with those treated with RP.” During the same period, another published analysis of 619,479 PCa cases, 206,852 of whom had radiation therapy, concluded, “Results indicated that RT was significantly associated with an increased risk of BLCa compared with the risk in those who received radical prostatectomy or non-RT.”[iii] In their title, the authors ominously referred to this as “high prevalence of secondary bladder cancer in men on radiotherapy for prostate cancer.” Thankfully, more precise forms of beam radiation have been developed with the objective of better targeting and less radiation scatter. Still, based on studies like those above, we recommend that PCa patients considering any form of beam radiation have a thorough discussion with their doctors on the risk of secondary cancers.

 

A new study (Sep. 2016) analyzed the relative risk of developing bladder (BlCa) cancer after primary radiation treatment for prostate cancer.[iv] The news is not good. Based on 346,429 prostate cancer radiation cases (SEER database, 1973-2011) study authors calculated the BlCa risks across all types of radiation modalities in comparison to rates in the general population. (This is what is meant by relative risk or RR.) They also took into account patient ethnicity, and the length of follow-up.

The findings are sobering. “All radiation modalities were found to have an increased RR of developing BlCa after 10 years, with brachytherapy having a significantly higher RR than external beam radiation (EBRT) or combined EBRT and brachytherapy [seed implants] in Caucasian men and a significantly higher RR than EBRT in men of other/unknown ethnicity.” In addition, the BlCa that occurred in the post-radiation patients was more aggressive than comparable cases in the general population

There were 6401 cases of BlCa in the radiated patients vs. 2464 cases that would be expected in the general population. The risk was greatest at 10 years following treatment (the most cases were diagnosed at 10 years, suggesting a long, slow development period for bladder cancer after radiation exposure. Of concern is the fact that the post-radiation bladder cancer was a more aggressive disease than would normally occur. This was true across all ethnic groups.

I was struck by the fact that brachytherapy itself posed the greatest risk. Seed implants have been around since the mid-1980s. As a prostate cancer treatment, it is usually recommended for men with low-risk, early stage prostate cancer. It has held particular appeal for younger men who are concerned about ED after surgery, since brachytherapy has low impotence rates for the first three years after treatment (by 3 years, ED is reported to range from 15-40%, but rates continue to climb with succeeding years) What seems tragically ironic is the thought that a 60-year old man who chooses brachytherapy is putting himself at higher odds of having aggressive bladder cancer when he is 70. Since there is no way to know in advance who will get bladder cancer and who won’t, it seems like a dark trade-off in order to preserve sexual function.

Radiation does not kill cancer quickly. It gradually impairs cancer cells’ ability to reproduce themselves. This is why radiation requires continuous exposure for a prescribed period, e.g. 5+ weeks of daily beam treatments, or permanent seed implants left in the body where not only the tumor but also the healthy prostate, bladder, and rectal wall receive some amount of radiation. On the other hand, Focal Laser Ablation as we perform it at our Center is an outpatient procedure that destroys the tumor, yet preserves sexual and urinary function.

The patients who come to our Center have done a lot of research to educate themselves. Most of them know that they don’t want surgery or radiation, and all of them know that a focal treatment means they must lead healthier lives than ever (nutrition, exercise, supplements, stress management) in order to keep the untreated portion of their prostates at minimum risk of a future tumor. They must also be motivated for follow-up monitoring, as is every man who is treated for prostate cancer regardless of treatment choice.

Will this study on bladder cancer risk be found by newly diagnosed patients who, in researching their options, decide that brachytherapy is not for them? Only time will tell, but I am grateful that we provide a non-radiation alternative that achieves all that brachytherapy promised, and more.

NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.

[i] Barnett J, Bruha M, Ozay F, Hyacinthe L. Muscle-invasive bladder cancer following radiotherapy for prostate adenocarcinoma. Urol Case Rep. 2021 Jan; 34: 101485.
[ii] Moschini M, Zaffuto E, Karakiewicz PI, Andrea DD et al. External Beam Radiotherapy Increases the Risk of Bladder Cancer When Compared with Radical Prostatectomy in Patients Affected by Prostate Cancer: A Population-based Analysis. Eur Urol. 2019 Feb;75(2):319-328.
[iii] Zhao S, Xie Q, Yang R, Wang J et al.. High prevalence of secondary bladder cancer in men on radiotherapy for prostate cancer: evidence from a meta-analysis. Cancer Manag Res. 2019;11:587-598
[iv] Keehn A, Ludmir E, Taylor J, Rabbani F. Incidence of bladder cancer after radiation for prostate cancer as a function of time and radiation modality. World J Urol. 2016 Sep 14. [Epub ahead of print]

 

About Dr. Dan Sperling

Dan Sperling, MD, DABR, is a board certified radiologist who is globally recognized as a leader in multiparametric MRI for the detection and diagnosis of a range of disease conditions. As Medical Director of the Sperling Prostate Center, Sperling Medical Group and Sperling Neurosurgery Associates, he and his team are on the leading edge of significant change in medical practice. He is the co-author of the new patient book Redefining Prostate Cancer, and is a contributing author on over 25 published studies. For more information, contact the Sperling Prostate Center.

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