The number of new cases of men suffering from metastatic prostate cancer has risen significantly in a decade's time, and is 72 percent greater in the year 2013 compared to 2004. This increase is especially worrying among men aged between 55 and 69 years old - the age group thought to benefit most from prostate cancer screening and early definitive treatment. These are some of the findings of a study published in Springer Nature's journal Prostate Cancer and Prostatic Diseases. According to authors Adam Weiner and Edward Schaeffer of Northwestern University Feinberg School of Medicine in the US, the research highlights a continued need to refine prostate cancer screening and treatment in the United States.

Over the past decade there has been a substantial shift in the screening practices used to detect the presence of cancerous cells in the prostate gland. This follows recommendations by the US Preventive Services Task Force (USPSTF) since 2008. It has led to a reduction in the number of men being screened, and an associated decline in the overall number of new cases of prostate cancer being reported.

Dr. Schaeffer's research team set out to find out whether the current status quo with regards to screening tests could be influencing the number of cases of advanced and metastatic prostate cancer eventually being diagnosed. To do so, they analysed information from the National Cancer Data Base. It included 767,550 men from 1,089 facilities nationwide diagnosed with prostate cancer between 2004 and 2013.

Three percent of those included in the study had metastases, which means that prostate cancer cells had spread to other parts of their bodies by the time the cancer was diagnosed. The incidence rate of metastatic prostate cancer in 2013 was 72 percent greater than that in 2004. This significant increase was found in all age groups. However, by far the largest increase in the incidence rate was seen among men aged 55 to 69 years. In the study group it rose from 702 new cases in 2004 to 1,345 in 2013, which amounts to an increase of 92 percent.

Weiner acknowledges that the findings cannot be explained completely as being a reaction to the USPSTF recommendations alone, as increases in metastatic prostate cancer began in the years prior to its release in 2008.

Notwithstanding, Weiner says that the results highlight the continued need for nationwide refinements in prostate cancer screening and treatment to prevent the occurrence of metastatic prostate cancer and subsequent deaths associated with the disease.

"This will be particularly critical for population health economics in the US considering the added cost of care for metastatic prostate cancer and an aging constituency whose population over the age of 65 will double to over a projected 80 million by the year 2050," Schaeffer notes. "Additionally, our findings and forthcoming changes in the number of elderly persons should provide impetus to improve treatments for men with metastatic prostate cancer whose cancer-specific survival has not changed significantly in the past two decades."