Scientists have pinpointed a gene that appears to play an important role in the development of prostate cancer.

The gene - known as MSR1 - has already implicated in hardening of the arteries associated with heart disease.

The findings suggest that at least some cases of prostate cancer may begin with an infection and inflammatory response.

It may tie infections to cancer of the prostate in a way that we haven't thought about before

Professor William Isaacs

MSR1 helps immune system cells called macrophages clean up cellular debris from bacterial infections and damaged fats.

Macrophage activity has been known to increase in the early stages of prostate cancer.

Scientists suspect that some MSR1 mutations might inhibit the ability of macrophages to clean up properly after prostate infections, leading to damage that may lead to cancer.

Mutations

Researchers from Wake Forest University and Johns Hopkins Medical School examined men from Caucasian and Afro-Caribbean decent to find out what percentage carried specific mutations of the gene.

They found that one type of mutation was present in 4.4% of Caucasians with prostate cancer, compared to just 0.8% who were free from the disease.

A different mutation of the gene was found in 12.5% of African-American men with prostate cancer, compared to 1.82% of unaffected men.

The researchers believe that MSR1 will prove to be just one of a number of genes linked to prostate cancer.

However, it does appear to play a significant role in the development of the disease.

Researcher Professor William Isaacs said: "This is the first time that MSR1 has been linked to cancer, and it may tie infections and similar environmental exposures to cancer of the prostate in a way that we haven't thought about before."

Dr Simon Gamble, of the Prostate Cancer Charity, said it was crucial to find genes that played a role in hereditary prostate cancer if scientists were to fully understand how the cancer grows in the body.

He told BBC News Online: "Using the information on the known MRS1 gene mutations and a reliable screening programme it may be possible to observe people with these mutations more closely and diagnose their cancer in the early stages, meaning that their chances of survival will be much higher.

"Secondly, the identification of a mutation in the MSR1 gene which makes the cancer spread more rapidly is very important in tailoring treatment to the individual patient.

"Patients with this gene mutation can now be identified and could therefore be treated with a stronger treatment regime than those who do not have the mutation."

However, Dr Gamble said many prostate cancers were not hereditary, and doubtless there were many more genes yet to be discovered which had an influence on prostate cancer formation in those non-hereditary cases.

The research is published in the journal Nature.