Men who have a family history of prostate cancer are more likely to develop the disease at a younger age and to die from it than men who don't have a history, according to a new study in the Journal of Urology (Vol. 168, No. 3: 906-913).

The study reviewed research findings on the qualities of hereditary prostate cancers. It reinforced the idea that men with a family history of prostate cancer should be screened regularly and have a biopsy when their prostate specific antigen (PSA) level is above a certain point.

Prostate cancer's hereditary aspect has only been studied since 1992. Researchers are still trying to piece together exactly how men are affected by this kind of cancer in their families.

By reviewing all studies on the topic that had been published through May 2001, Ola Bratt, MD, PhD, of the Unit for Urology at Heinsborg Hospital in Heinsborg, Sweden, concluded that heredity is the "strongest risk factor" for prostate cancer and that family history has a "profound" effect on the incidence of the disease.

Men whose fathers or brothers had prostate cancer are, on average, diagnosed six to seven years earlier than men with no family history of this disease. Men with three or more relatives with prostate cancer have a 35% to 45% risk of developing prostate cancer.

A man whose father had prostate cancer before age 60 has a 20% chance of developing prostate cancer, compared to just 8% for men without such a history. The risk may be slightly greater for men whose brothers had prostate cancer than for those whose fathers had the disease, said the authors.

"Among men with early onset prostate cancer, hereditary susceptibility is much more common” when compared to men who are diagnosed with prostate cancer when they are older, said Bratt.

More than 40% of the cases in men diagnosed with prostate cancer before the age of 55 may be due to heredity, according to the article.

Inherited cancers are usually diagnosed at younger ages than those that occur without the influence of genes.

Bratt noted that there was a smaller, six-year difference in the age of onset between hereditary prostate cancer and the age of diagnosis for those men who did not inherit their disease. This compares to a 20-year difference between those who inherit other cancers such as breast, ovary, and colon compared to people who develop those cancers spontaneously.

This means, according to the author, that genes probably do not play as big a role in the development of inherited prostate cancer as they do for the other cancers.

"As a result of earlier onset, a greater proportion of men with hereditary prostate cancer die of the disease," he said.

So far, the exact genes that may cause prostate cancer or increase a man's chances of developing it have not been identified, although many genes that may play a role are being studied.

Men with a family history of prostate cancer whose PSA is slightly or moderately elevated (above 3 ng./ml or higher) should have a biopsy, Bratt wrote. Men whose biopsies are negative should have a "vigilant follow-up" if they have a family history of prostate cancer.

The American Cancer Society recommends that men at high risk for prostate cancer should be offered a PSA and rectal exam annually starting at age 45. Men at high risk include African Americans and men who have a first-degree relative (father, brother, son) diagnosed with prostate cancer at an early age.

Bratt said that it is "wise" for men to inform their doctors about their family history.

"Doctors are always short of time, and often forget to ask about heredity and it is of great importance that men at high risk are identified so that they can be offered screening," Bratt said.

But, he added, "It is also important to stress that the vast majority of prostate cancer cases are not hereditary, and that men with only one family member with prostate cancer diagnosed at average age should not worry too much about their risk."

Mark S. Litwin, MD, MPH, associate professor of urology and health services at the Geffen School of Medicine and School of Public Health at UCLA, called Bratt's article a "thoughtful analysis" of the literature on heredity and risk factors for prostate cancer.

He agreed that there appears to be "a strong association" between family history and prostate cancer diagnosis at a younger age, and that these men should be undergo screening.

He echoes the sentiment that doctors should be aware of a man's family history.

"Ultimately it is a man's personal responsibility to talk with his primary care physician and make decisions regarding cancer screening, but these decisions should certainly be informed by a family history for prostate cancer," says Litwin.