My Google prostate cancer news pipeline is fit to burst. What everybody is so excited about is the discovery of several new genetic variations which appear to be associated with a diagnosis of PC. I had heard that seven new abnormal gene sequences or “SNP”s, had been found . . . but now it may be up to ten. (These follow on the heels of previous discoveries reported last month.)
The goal of researchers is to be able to offer screening for PC with a test that could pinpoint biomarkers associated with higher-grade cancer. This would allow doctors to distinguish between men who need aggressive treatment and those with “indolent” or slow-growing tumors who could get by with careful monitoring.
Alternatively, identifying abnormal genes may present an opening for treatment with gene therapy.
What I found interesting about this story is the information that one of the genetic mutations discussed appears to be on the “x” chromosome, which a man receives from his *mother* (only). We don’t often think of prostate cancer as being passed on from mother to son. But it is, apparently.
In a minute I will cite some excerpts from SNPwatch.com about the maternal connection to PC. But first:
Have you ever wondered which of your parents (if any) is/are to blame for your diagnosis of PC? Well, I have.
Until now it seemed pretty straightforward. His Dad had PC (although a more benign form of it), which he passed on to T. But turns out it’s not that simple. Mom counts too, because she had breast cancer at 32, and that is considered an additional risk factor for developing PC.
I’m thinking maybe the one who is *really* to blame is the Jewish God, who seems to have bestowed upon his chosen people a dizzying array of oncogenes.
I guess I’m the incarnation of nasty. Last Father’s Day, Ted asked me for advice about what to write on his Dad’s greeting card. I hesitated for a moment and then said, “Well, how about, ‘Thank you for the gift that keeps on giving,'” or maybe, “Dad, you’re swell. There’s nothing you haven’t ever shared with me.” We both laughed.
T. eventually chose a card that said, “Dad, you’re Superman, Batman and Captain America all rolled into one.”
Superman with prostate cancer? Why not? He’s getting on, too.
Anyway, here’s some information about mothers and sons with PC from SNPwatch.com, which “gives you the latest news about research linking various traits and conditions to individual genetic variations.”
Following on the heels of last month’s New England Journal of Medicine study on genetic associations with prostate cancer risk are three new papers in Nature Genetics. The new batch not only replicates earlier discoveries but adds at least 16 potential new associations to the mix. While there are too many to list here individually, a few are worthy of particular mention.
Iceland’s deCODE Genetics compared the genotypes of 10,000 men diagnosed with prostate cancer with those of 29,000 healthy controls. Instead of conducting a genome-wide association study (GWAS) of hundreds of thousands of single nucleotide polymorphisms (SNPs), the authors chose to follow up on two promising candidates identified in previous GWAS. In the current study, both showed associations to prostate cancer risk.
**One of the candidates, rs5945572, is located on the X chromosome. Men only have one X chromosome and thus one copy of rs5945572. Those who had the “A” version of the SNP had slightly higher odds of prostate cancer.
The fact that the SNP is located on the X chromosome—which sons inherit only from their mothers—may help to explain why brothers of men with prostate cancer are at greater risk of being affected than fathers are. If a father has the protective “G” version of the SNP on his X chromosome, he cannot pass it on to his sons; the contribution of this SNP to a man’s risk of prostate cancer is determined by which version his mother passes to him.
Further replication studies will have to be performed before all of these associations are fully accepted by the scientific community.