Prostate Cancer in Younger Men a Separate Phenotype

Kathleen A. Cooney, MD

Prostate cancer that emerges when a man is 55 years of age or younger is a distinct phenotype of the disease, and should be treated and researched accordingly, the authors of a recent study¹ found.

In their paper based on a review of studies of prostate cancer and prostate cancer in younger men, Salinas et al, of the University of Michigan Comprehensive Cancer Center, found that more than 10% of prostate cancer cases occur in men in this younger age group, with the rest occurring in older men. The occurrence of the disease in men in the younger group increased by 5.7-fold, from 5.6 to 32 cases per 100,000 person-years, between 1986 and 2008, according to the authors, who added that the rise in cases in younger men cannot be entirely attributed to increased use of screening for the disease.

The disease differs in the younger population, compared to in older men, in three ways, the study authors found.

First, “among men with high-grade and advanced-stage prostate cancer, those diagnosed at a young age have a higher cause-specific mortality than men diagnosed at an older age, except those over age 80 years. This finding suggests that important biological differences exist between early-onset prostate cancer and late-onset disease,” the authors wrote in their abstract.

“Early onset prostate cancer tends to be aggressive, striking down men in the prime of their life. These fast-growing tumors in young men might be entirely missed by screening because the time frame is short before they start to show clinical symptoms,” said Kathleen A. Cooney, MD, one of the study’s authors and a professor of Internal Medicine and Urology at the University of Michigan, in an article on the institution’s website.²

In the paper, the authors added that prostate cancer that begins at an earlier age “has a strong genetic component, which indicates that young men with prostate cancer could benefit from evaluation of genetic risk.” In fact, such tests for diagnosing prostate cancer have proven to perform better in younger men, the authors noted. In addition, they wrote, science could benefit from studying this younger cohort of men, because their cancers are more likely to hold secrets about the genes associated with prostate cancer susceptibility and development.

Finally, the authors found, although most men with early-onset prostate cancer are diagnosed with low-risk disease, they have a longer life expectancy, which means they may spend more years dealing with the side effects of treatment, and face a longer-term risk of disease progression and resulting death.

“For these reasons, patients with early-onset prostate cancer pose unique challenges, as well as opportunities, for both research and clinical communities,” the authors wrote. “Current data suggest that early-onset prostate cancer is a distinct phenotype— from both an aetiological and clinical perspective—that deserves further attention.”

References

1. Salinas CA, Tsodikov A, Ishak-Howard M, Cooney KA. Prostate cancer in young men: an important clinical entity. Published online May 13, 2014. Nat Rev Urol. 2014;11:317-323.
2. University of Michigan Comprehensive Cancer Center. Prostate cancer in young men— more frequent and more aggressive? U-M Cancer Center website. http://www.mcancer. org/news/archive/prostate-cancer-young-men-more-frequent-and-more-aggressive. Published July 15, 2014. Accessed July 18, 2014.