Ring finger length may help predict prostate cancer survival, claims study.
Tests showed that cancer victims responded better to an anti-tumour drug if their ring finger was shorter than the index finger - the finger next to the thumb.
Testosterone is a hormone that is known to help prostate tumours grow.
Doctors who tested the theory on 142 volunteers found those with short ring fingers responded better to dutasteride, a drug that fights cancer by blocking the effects of testosterone on the prostate.
Numerous studies show finger length is linked to the risks of conditions ranging from heart disease and osteoarthritis to depression and Motor Neurone Disease.
The difference between the two fingers is determined by exposure to testosterone while a baby is still in the womb.
According to research, this can have a profound effect on health later in life.
The risks increase with age, with men over 50 more likely to develop a tumour, and there is a strong genetic element to it.
However, the latest findings by experts at Seoul National University in South Korea suggest that doctors might soon be able to predict who will respond best to treatment by measuring men's fingers.
Although the men in the study did not have cancer, they did have enlarged prostates or benign prostatic hyperplasia - a common condition in men over 50 where the prostate grows and blocks the flow of urine.
Dutasteride has been used for several years to treat BPH and prostate cancer. The volunteers took the drug every day for six months.
When their prostate glands were measured to see if they had shrunk, there was a much bigger reduction in men with short ring fingers.
"These results suggest finger length might predict the response to dutasteride treatment," the Daily Mail quoted the researchers as writing in the report.
The study has been published in the British Journal of Urology.