In a new twist in the ongoing research on prostate cancer, it turns out that the number of sons a man has or does not have could determine his risk for developing prostate cancer later on in life. Yes, you read that correctly — the number of sons a man sires has been linked to this deadly form of cancer, according to a new life course study conducted by a joint U.S. and Israel research venture.
The study, which was published in a January issue of the Journal of the National Cancer Institute, states that men who have only fathered daughters are facing a higher risk of developing prostate cancer in comparison to men who have had at least one son. On top of this surprising finding, having more sons means an ever better decrease in prostate cancer risk. What is the link? It seems to be all in the male’s chromosomes.
Researchers at Columbia University’s Mailman School of Public Health and the Hebrew University of Jerusalem teamed up to look at how men with only daughters face a higher risk of prostate cancer due to a possible defect occurring on their Y chromosome. They looked at men who had fathered children of both sexes and who were registered in a family-based research cohort that was run out of Israel.
By poring over the information on 38,934 men, who were observed from the years of 1964 to 1976 when they produced offspring, and then until 2005, the researchers came to one main conclusion. Namely, genes attached to the Y chromosome play a possible role in the risk of prostate cancer occurring in the research cohort.
According to the study’s lead researcher, Susan Harlap, MD, “We surveyed vital status and cancer incidence, and found a strong trend for a decrease in prostate cancer risk as the number of sons increased. We anticipate that this finding will have a significant impact on the direction of research in this field going forward.” The trend showed that a whopping 40% of men in the cohort who did not have sons faced an increase in prostate cancer risk.
To look at things a bit more specifically, a man who has a damaged Y chromosome faces a reduced chance of fathering a son, whereas his having a damaged X chromosome has the opposite effect — the man faces a lesser chance of fathering a daughter. Whether a man has a son or a daughter all hinges on the chromosome factor: a child’s sex is dependant on whether an X or Y chromosome is delivered by the father.
As Dr. Harlap explains, “Our findings suggest that the biological significance of a lack of sons — whatever it is that leads to increased risk of prostate cancer — becomes increasingly important as family size increases. Overall, our findings are consistent with hypotheses that tie Y chromosome loci to prostate cancer, although other explanations cannot be excluded.”
While it may sound unrelated, this link between sons and prostate cancer is not entirely far-fetched. Genetics is still a very cloaked and mysterious science, with multiple layers of discoveries such as this one being made all the time. We’ll keep you posted on any new developments in the field of life course studies and genetics in the future as they happen.