Invasive prostate cancer incidence rising among young men; cause elusive
Incidence of prostate cancer among adolescents and young adults has increased in the United States and many other countries during the past 3 decades, according to study results published in Cancer.
Further, young men with prostate cancer appeared less adequately staged at diagnosis and at higher risk for metastatic disease and death compared with older-aged men.
“Incidence of invasive cancer among [men aged 20 to 40 years] in the U.S. has been increasing in distinct contrast to older Americans, among whom incidence has been decreasing,” Archie Bleyer, MD, researcher in the department of radiation medicine at Oregon Health & Science University, told HemOnc Today. “Primary care providers should not exclude the possibility of prostate cancer in their male patients who are between [ages] 20 and 40 years, a potential diagnosis that would rarely have been considered previously. Oncologists, too, may want to include the possibility in their differential diagnosis.”
Bleyer and colleagues analyzed data from the SEER database and Institute for Health Metrics and Evaluation Global Burden of Disease database to determine the cause of increasing prostate cancer incidence among adolescents and young adults.
Among all groups aged 15 to 39 years, researchers observed global increases in prostate cancer incidence at an average rate of 2% per year since 1990 (P < .01).
SEER data showed the proportion of men with distant metastases at the time of prostate cancer diagnosis appeared more than twice as high among those aged 25 to 40 years (9%) compared with those aged 40 to 80 years (4%). Moreover, 50% of those diagnosed between ages 15 and 24 years had unstaged disease, compared with 10% of men aged 25 to 29 years, 6% aged 35 to 39 years, and 2% aged 40 to 80 years.
Prostate carcinoma incidence increased 11-fold among American men between the ages of 25 and 39 years from 1975 to 2010 and decreased subsequently to a level in 2015 that was sixfold higher than that of 1975 (annual percent change, 8), according to the researchers.
“Prostate carcinoma was one of the reasons for the increasing incidence of cancer in this age group, albeit much less than carcinomas of the thyroid and kidney,” Bleyer told HemOnc Today.
Moreover, the 5-year overall relative survival rate in the U.S. was 30% among those aged 15 to 24 years, 50% among those aged 20 to 29 years, 80% among those aged 25 to 34 years, and between 95% and 100% among those aged 40 to 80 years.
Not knowing how much of the increased incidence was due to PSA screening served as a study limitation.
“The cause of the increasing incidence is unknown,” Bleyer told HemOnc Today. “Potential contributing factors that should be investigated are underdiagnosis, PSA utilization, overdiagnosis, obesity, decreased physical activity, HPV infection, substance or environmental exposure trends, and referral patterns. How the biology of these cancers in older adolescent and young adult men differs from that in older men also remains to be determined.”
In the United States, much of the increase in prostate cancer incidence among young men occurred during the era of increasing PSA screening (1990-2000), followed by a stabilization of incidence rates, Oliver Sartor, MD, professor of medicine and medical director of Tulane Cancer Center and C.E. and Bernadine Laborde Professor of Cancer Research at Tulane University, wrote in an accompanying editorial.
“There have been tremendous increases in the survival rates for young men diagnosed with prostate cancer in the PSA era (based on U.S. data), as would be expected if PSA testing were implicated,” Sartor wrote. “That said, metastatic rates are higher in younger men, probably because there are fewer men in this age group who have regular PSA screening.”
However, this article is currently not enough to change clinical practice, Sartor added.
“Clinicians need to be aware, however, that age alone cannot be used to exclude prostate cancer as a diagnosis,” he said. “Being cognizant that prostate cancer can occur in men younger than 40 years is important and impactful for those afflicted with this disease.” – by Jennifer Southall
For more information:
Archie Bleyer, MD, can be reached at Knight Cancer Institute at Oregon Health & Science University, 2884 NW Horizon Dr., Bend, OR 97703; email: firstname.lastname@example.org.
Disclosures: Bleyer reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures. Sartor reports no relevant financial disclosures.