High-risk prostate Ca: New study sheds light on RP vs. RT

February 28, 2019

Surgery was associated with improved cancer-specific and overall mortality compared with radiation therapy, according to a recent study.

“Journal Article of the Month” is a new Urology Times section in which Badar M. Mian, MD (left), offers perspective on noteworthy research in the peer-reviewed literature.  Dr. Mian is professor of surgery in the division of urology at Albany Medical College, Albany, NY.

When addressing the treatment for high-risk prostate cancer, all of the guidelines recommend either surgery or radiation therapy as a valid option for initial treatment. In a recent analysis of Surveillance, Epidemiology, and End Results data, Huang et al report that prostatectomy was associated with improved cancer-specific and overall mortality when compared to primary radiation therapy in men age <60 years (J Urol 2019; 201:120-8).

The authors analyzed data from the most recent SEER registry, focusing on younger men (<60 years) who had Gleason score 8-10 prostate cancer, without nodal or distant metastases. After excluding men with metastases or without initial surgery or radiation or short follow-up (<2 years), 2,228 men met the study criteria. The median age was 56 years and the median follow-up was 44 months.

Also by Dr. Mian: Many low-risk PCa patients on AS may be lost to follow-up

Of these 2,228 men, 1,459 (65.5%) underwent surgery and 769 (34.5%) were treated with radiation therapy. Within the radiation therapy cohort, external beam alone was used in 583 (75.8%) and external beam plus brachytherapy was used in 186 (24.2%). Among the men treated with initial surgery, 266 (18.2%) required adjuvant radiation therapy. The surgery cohort was more likely to be somewhat younger, Caucasian, and with PSA <20 ng/mL.

The estimated 7-year cancer-specific mortality was lower in the surgery cohort compared to the radiation group-8.2% and 12.1% (p<.001), respectively. The 7-year overall mortality was similarly reduced in the surgery group-10.2% versus 21.2%, respectively. On multivariable analysis, prostatectomy was associated with a significant decrease in cancer-specific mortality and overall mortality, after controlling for age, Gleason score, clinical T stage, and PSA level (p=.001). In men undergoing surgery, there was a 16.5% decrease in cancer-specific mortality and a 40.6% decrease in overall mortality compared to initial radiation.

This study appropriately focused mostly on men in their 50s with high-risk disease who are likely to be healthier and with fewer competing causes of mortality. While a number of important clinical variables were included in the analysis, some of the most pertinent data were not available: comorbidities, use and duration of hormonal therapy, and the dose of radiation. It is possible that the lower mortality from surgery noted in this analysis may be due to selection of healthier patients for ­surgery.

Next: Effects of hormonal therapy must be taken into accountEffects of hormonal therapy must be taken into account

Hormonal therapy, which has long been used in combination with radiation therapy of high-risk cancer, is associated with both short-term and long-term systemic toxicity. The adverse effects of hormonal therapy may be a significant contributing factor for the higher overall mortality noted with radiation therapy.

If history is our guide, it’s unlikely that a large, randomized controlled trial will be successfully conducted in the space of localized prostate cancer. We are then left to make the best use of available data from various sources such as SEER or other larger registries or single-institution experience. When counseling our younger patients about potential advantages of surgery, it’s essential to be cognizant of the limitations and confounding factors listed above.

 

 

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