Is there a link between prostate cancer and finger length?

The length of a man’s fingers may affect his lifetime risk of prostate cancer.

It sounds like an urban legend. And to be fair, the idea that having a longer ring finger than index finger comes with more risk started with years of simple observation. But it has picked up credibility in the past few years as researchers backed it with data.

If you’re a man, and you’re looking down at your hand right now, don’t panic. Much research remains to be done.

But it is worth paying attention to this field, especially if you have other risk factors. One day this simple observation may give your doctors one more tool to diagnose — and treat — prostate cancer early.

What the research says

In a study published in 2011, researchers analyzed more than 1,500 prostate cancer patients and 3,000 healthy control subjects over 15 years.

They found that men with a high 2D-4D ratio — meaning their index fingers were longer than their ring fingers — had about a 33 percent risk reduction for prostate cancer.

Further research has shown that the opposite — when ring fingers are longer than index fingers — is associated with a higher detection rate of prostate cancer, too.

The question is why? The answer may come from HOX genes.

HOX genes play a major role in the body’s development. In the womb, they help guide development of organs such as the prostate and kidneys, but also of your fingers.

HOX genes are out of proportion in prostate cancer tumors, according to 2015 research. That same research suggests HOX might be a target for prostate cancer therapy as a result.

It’s still not entirely clear how HOX connects to hormones such as estrogen and androgen, which play a part in cancer development. The connection is important, because index finger length is linked to estrogen. A low 2D-4D ratio is associated with higher levels of estrogen before birth.

Understanding how those hormones interact with HOX could give us a new target in the fight against prostate cancer.

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