Prostate cancer is now the most common form of male cancer, according to figures from the Office of National Statistics.

Researchers found that it had now overtaken lung cancer as the biggest health threat to men.

Between 1990-1996 the number of new cases increased by 50%, compared to a 25% drop in new cases of lung cancer.

But experts say the increase is due to better detection, rather than more people contracting the disease.

Test

The Prostate Specific Antigen test (PSA) now enables doctors to spot and treat the cancer at an early stage, leading to fewer deaths.

Around 22,000 cases of prostate cancer are diagnosed in the UK each year and a new "active surveillance" trial for men with early prostate cancer has recently been launched at the Institute of Cancer Research.

The number of people asking for the PSA test has increased enabling us to highlight more cases

Dr Richard Sullivan, head of clinical programmes for Cancer Research UK

This offers patients PSA tests on a regular basis, rectal examinations and a biopsy every two years.

These results will then be used to help research which men will develop aggressive prostate cancer.

Dr Richard Sullivan, head of clinical programmes for Cancer Research UK, added that the figures on prostate cancer were not "surprising".

"There's no real increase in the number of prostate cancer cases. It's just that the number of people asking for the PSA test has increased enabling us to highlight more cases.

"Firstly, we know that lung cancer rates have been decreasing because of the impact of educational programmes.

Smoking

"During the 1960s and 1970s young men and teenage boys didn't take up the habit so what we are seeing now is incredible decreases in mortality rates of smoking-related cancers.

"I'm not surprised at all by the rise in prostate cancer cases.

"It's been going up in the United States for the last four to five years and is a result of the PSA test.

"This increase is not due to an actual increase in the number of prostate cancer cases but an increased pick-up from the use of the PSA test."

Overall cancer figures showed that in 1999 the number of cancers had risen to 108,800 in men and 112,200 in women - an increase of 2,100 cases (2%) for men and 2,300 cases (2.1%) for women compared to 1998 statistics.