A 45 percent reduction in prostate cancer-specific mortality? Not exactly.
Posted Oct 08 2010 12:00am
According to a report yesterday in Consumer Affairs , “American men with prostate cancer were 45 percent less likely to die from the disease in 2006 than they were in 1999.”
To be fair, what the federal government actually said was that, “American men with prostate cancer were 25 percent less likely to die from the disease in 2006 than they were in 1999″ (but even then, the actual reduction was only 24.2 percent; see below.) Consumer Affairs compounded a typographical transcription (changing 31 to 13) into a mathematical error.
Specifically, AHRQ says that the rates for prostate cancer-specific mortality (PCSM) were:
31/100,000 in 1999 and 23.5/100,000 in 2006 overall (a 24.2 percent decrease)
29/100,000 in 1999 and 22/100,000 in 2006 for White men (a 24.1 percent decrease)
69/100,000 in 1999 and 50.5/100,000 in 2006 for Black men (a 26.8 percent decrease, but still more than twice the overall rate)
23/100,000 in 1999 and 18/100,000 in 2006 for Hispanics (a 21.7 percent decrease)
17/100,000 in 1999 and 14/100,000 in 2006 for Native Americans (a 17.6 percent decrease)
14/100,000 in 1999 and 10/100,000 in 2006 for Asian Americans and Pacific Islanders (a 28.6 percent decrease)
They also stated that:
The rate of PCSM in men aged 65 years or more dropped from 205/100,000 in 1999 to 164/100,000 in 2006 (a 20.0 percent decrease).
AHRQ makes no comment on why PCSM might have dropped by 24.2 percent from 1999 to 2006. Nor do they comment on the growth in the absolute numbers of men projected to die from prostate cancer by the American Cancer Society after 2006 (from 27,350 in 2006 to 32,050 in 2010; a 17 percent increase).
It is not at all clear to The “New” Prostate Cancer InfoLink why AHRQ should have decided to make this statement several months after issuance of the original data. Maybe it had something to do with Prostate Cancer Awareness Month (which ended in September). It does seem likely that there was a significant decline in PCSM between 1999 and 2006. It is much less clear what the real size of that decrease in mortality might have been or whether it has been sustained since 2006.
A major problem in the interpretation of all data like these is that we do not have a reliable nationwide cancer database in the USA we have a representative one (the SEER database) based on cancer information from selected regions of the country. This is used to make estimates and projections which are highly dependent on the assumptions and models used in making those estimates and projections.