This question came up in a subsequent post…let me address it clearly here…
Prostate cancer is primarily a sporadic cancer, not hereditary or familial… and those are the only 3 types that exist. Most other common malignancies (not all) are also sporadic, but this discussion is all about
prostate cancer only.
What is a sporadic cancer?
Most prostate cancers (about
75%) are considered sporadic, meaning that
damage to the genes occurs AFTER a person is born. What I just said was that the damage/change happens to their GENES, but just because it has something to do with GENES is not the same things as being hereditary or familial…people often incorrectly mix discussion of genes with it being driven by hereditary or familial.
Before going further in this discussion it is important to know that
the largest single risk factor for prostate cancer is AGE. It has been shown repeatedly, in multiple autopsy studies in the US, that with a high degree of repeatability the percent of men who die in accidents are found to have PC at rates which very closely approximate their age. 50% of 50-year olds, 60% of 60-years olds, 70% of 70-year olds, and so on. AGE is the single most relevant
risk factor for having PC.
The most significant
correlation factor for being diagnosed with PC is having a relative who was diagnosed with PC. (Please note the important but subtle difference in "having" and "being diagnosed.") This correlation is NOT hereditary PC, which is discussed in the next paragraph, below. There is
a common misconception that PC runs in families…the reality is it runs everywhere and it is based mostly on age. Family aggregation of PC diagnosis is largely
caused by increased diagnostic activity using PSA testing. One study showed that men with 2 brothers with PC were 22-times more likely to be
diagnosed than the general population. Unequivocally, the more you look for PC, the more likely you will find PC.
Besides sporadic cancer (75% of PC), the other two types are (1) familial prostate cancer (about
20% of cases) which occurs because of a
combination of shared genes and shared environment/lifestyle factors (ie., brothers tend to have the same dietary habits), and (2) even more rare is hereditary (inherited) prostate cancer (only about
5% of all cases) when gene mutations are passed within a family from one generation to the next. Both the links Pratoman also provide this same statistic…in fact
the very first sentence of Pratoman's MSKCC link says (just before the part he copied/pasted):
“about 5 to 10 percent of all prostate cancers diagnosed are hereditary, meaning that an increased risk for the disease runs in the family.”So yes, hereditary PC is out there…for about
5% of all cases…!
It was Dr Patrick Walsh, father of modern nerve-sparing RP surgery, who said: "
Prostate cancer is so common that even if there is a hereditary factor, there will be other members of the family who will get the disease sporadically."
.
Post Edited (NKinney) : 11/5/2015 1:29:55 PM (GMT-7)