FINGER LENGTH AND PROSTATE CANCER RISK

Men whose index finger is longer than their ring finger are at a lower risk of prostate cancer than those with a finger pattern the other way round, according to a new study in the British Journal of Cancer.

The relative length of the first and third fingers is set before birth, and it is thought to relate to the levels of sex hormones the baby is exposed to in the womb. Babies exposed to less of the male sex hormone testosterone are more likely to have longer index fingers.

Finger Length and Prostate Cancer

Over a 15-year period, researchers from The University of Warwick and The Institute of Cancer Research (ICR) collected data on finger length in 1,524 patients with prostate cancer as well as 3,044 healthy people. Men were shown pictures of hands with different finger lengths and asked to identify the one most like their own right hand.

The most common finger length pattern, seen in more than half the men in the study, was a shorter index than ring finger. Men whose index and ring fingers were the same length (about 19%) had a similar prostate cancer risk to those with a shorter index than ring finger. However, men whose index fingers were longer than their ring finger were 33% less likely to have prostate cancer.

Risk reduction was even greater in men aged under 60, say the researchers, who found that this younger group were 87% less likely to be in the prostate cancer group.

Testosterone Exposure

The researchers believe that being exposed to less testosterone before birth helps protect against prostate cancer later in life. The phenomenon is thought to occur because the genes HOXA and HOXD control both finger length and development of sex organs.

“Our results show that relative finger length could be used as a simple test for prostate cancer risk, particularly in men aged under 60,” says joint senior author Professor Ros Eeles from the ICR and The Royal Marsden NHS Foundation Trust. “This exciting finding means that finger pattern could potentially be used to select at-risk men for ongoing screening, perhaps in combination with other factors such as family history or genetic testing.”

The study was funded by Prostate Cancer Research Foundation and Cancer Research UK.

Diagnosing Prostate Cancer

Helen Rippon, head of research at The Prostate Cancer Charity in the U.K., says in an emailed statement: “Diagnosis of prostate cancer is not a simple affair and the best blood test we have, known as a PSA test, tells us only that something might be wrong with the prostate, not whether it is cancerous or not. Anything that adds to our knowledge about whether a man is likely to develop prostate cancer or not is to be welcomed, especially when it is something as easy as looking at the length of his fingers.

“This research also adds to the growing body of evidence that the balance of hormones we are exposed to before birth influences our health for the rest of our lives.”

Rippon says men who check their hands and find they have a shorter index finger should not be unduly concerned. “They share this trait with more than half of all men and it does not mean they will definitely develop prostate cancer in later life,” she says.