Although cases of aggressive prostate cancer appear to be on the rise, it's still rare for prostate cancer to spread. Researchers at the Northwestern University Feinberg School of Medicine found that only 3 percent of prostate cancer cases have already started spreading when the patient is diagnosed.
Cases of metastatic cancer, cancer that has spread from the point where it started to other parts of the body, has doubled in men aged 55 to 69. Yet, the overall prevalence of prostate cancer is not any more common.
"One hypothesis is the disease has become more aggressive, regardless of the change[s] in screening," lead study author Edward Schaeffer told NBC News. "The other idea is since screening guidelines have become more lax, when men do get diagnosed it's at a more advanced stage of [the] disease. Probably both are true. We don't know for sure, but this is the focus of our current work."
Source: NBC News, Wochit, Cancer.gov