Early evidence of increase in higher-risk prostate cancer deaths seen in analysis of data
An analysis of data on approximately 87,500 men treated for prostate cancer since 2005 found a notable increase in higher-risk cases of the disease between 2011 and 2013. The retrospective analysis of patient data found the proportion of men with diagnoses of intermediate- and high-risk disease increased by nearly 6% in those years. These findings were presented at the 2015 Genitourinary Cancers Symposium, in Orlando, Florida.
Although a rise in mortality has not yet been seen, the authors estimated this apparent trend could produce 1,400 additional prostate cancer deaths per year (based on the 2014 estimated number of new prostate cancer cases and the relative survival of patients with low- versus high-risk cancer). They emphasized, however, that the findings must be confirmed through further research.
"This study, while preliminary, adds new insight to the ongoing debate on the risks and benefits of PSA screening for prostate cancer," said Charles Ryan, MD, ASCO Expert and Genitourinary News Planning Team Member. "These findings alone do not warrant changes in physician practice, but they do suggest that men should continue to be encouraged to talk with their doctors about screening to decide whether it is appropriate for them."
In this study, researchers analyzed data on 87,562 men with prostate cancer diagnosis between January 2005 and June 2013. Patient data were collected from the National Oncology Data Alliance (NODA, a registered trademark of Elekta Medical Systems), a proprietary database that captures cancer cases at more than 150 US hospitals. This database was selected because it included 2011 to 2013 data that were not available in the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database at the time of this analysis.
Blood PSA level greater than 10 signifies intermediate- or high-risk prostate cancer, irrespective of tumor stage and grade. From 2005 to 2011, the proportion of men with prostate cancer and PSA greater than 10 decreased gradually. Between 2011 and 2013, however, the proportion of men with intermediate- or high-risk cancer, based on blood PSA level, increased by 3% per year.
Based on 233,000 new prostate cancer cases predicted in 2014 in the United States, the authors estimated that this trend translated to 14,000 additional higher-risk prostate cancer diagnoses nationwide in 2014, compared to 2011.
The authors predicted that at least 1,400 additional men may die from prostate cancer each year. This estimation takes into account 10-year prostate cancer survival rates, which are approximately 95% for low-risk, 75% to 90% for intermediate-risk, and 60% to 80% for high-risk disease.
"Our study is the first to measure the changes in prostate cancer presentation in the period following the US Preventive Services Task Force's PSA screening recommendations," said lead study author Timothy E. Schultheiss, PhD, a professor and director of Radiation Physics at City of Hope in Duarte, California.
"Given the rise in intermediate- and high-risk prostate cancers seen in our analysis during this timeframe, men who are at increased risk for prostate cancer, especially those with a family history of prostate cancer, should consider talking with their doctor about PSA screening."
In a follow-up to this study, the researchers plan to update this analysis as new registry data become available.