Historically, prostate cancer has been a disease of older men. That, however, is steadily changing and researchers at the University of Michigan say it may be time to rethink how clinicians view prostate cancer.
Early-onset prostate cancer may be a unique clinical entity that is rising significantly in the United States. In addition, it is a form of the disease that appears to be associated with more genetic factors than environmental risk factors.
“Some variants are present in the younger patients more commonly,” said study author Kathleen Cooney, MD, of the University of Michigan in Ann Arbor, MI. She and her colleagues have been analyzing Surveillance, Epidemiology, and End Results (SEER) data and found that prostate cancer diagnosed in younger men (under age 55) has increased nearly 6-fold in the last 2 decades and may be a different form of prostate cancer than what occurs in older men.1
Dr. Cooney said these findings are important because they suggest that future research into early-onset cases may point to additional risk alleles that will help improve the understanding of the etiology of prostate cancer. “We are now sequencing the germlines of these men,” said Dr. Cooney in an interview with Cancer Therapy Advisor. “Polymorphisms may provide more data.”
Identifying the role of rare alleles, such as HOXB13 mutations and other genes, may have immediate clinical applications. In 2012 approximately 10% of all cases of prostate cancer involved early-onset disease. The Michigan researchers report that the majority of young men diagnosed with prostate cancer tend to have low-grade, organ-confined tumors.
They theorize that this unique clinical feature moves this type of prostate cancer into another category. However, it is premature to make any type of name change or official reclassification. “It is too soon, but our work is looking at how we [may] sort out different types,” said Dr. Cooney.
Early-onset prostate cancer tends to be aggressive and these fast-growing tumors may be entirely missed by screening due to the short timeframe before they start to show clinical symptoms. The CDC and other federal agencies follow the prostate cancer screening recommendations set forth by the U.S. Preventive Services Task Force.
It currently recommends against PSA-based screening for men who do not have symptoms.2 This is a fairly recent change in policy that moved away from screening asymptomatic men and may be too much of a wide blanket approach.
“I am concerned about what the overall impact is going to be because of these changes in recommendations and I can tell you that we are already seeing men presenting at a later stage in disease,” said Dr. Cooney.
Instead, Dr. Cooney and colleagues suggest that genetic counseling or increased surveillance in younger men with a family history of prostate cancer may be warranted. David Penson, MD, MPH, of Vanderbilt University in Nashville, TN, said the rate of early-onset prostate cancer is growing. However, he said the clinical significance of being diagnosed with prostate cancer at a younger age isn’t entirely clear.