In a landmark trial of cancer patients, the US researchers found that some of them were dying earlier, on average, than expected.

The trial, published in the Journal of the American Medical Association, followed more than 7,000 people over 13 years and found that the risk of dying in the first six months of life was four times higher for people with a pre-existing disease, or those with a genetic mutation.

Researchers from Johns Hopkins University and the National Cancer Institute used data from the National Health and Nutrition Examination Survey, a long-running survey of Americans, to identify the factors that could have an impact on survival.

Those with the highest risk of mortality in the six-month period were those with at least a 10-point higher risk of developing prostate cancer, and those who were obese.

The study looked at more than 9.7 million deaths recorded in the US from 1995 to 2011.

“There is a real risk of a patient dying of prostate cancer at any stage,” Dr Paul Nevin, the lead researcher from Johns Johns Hopkins, said.

“In this trial, we saw an overall significant reduction in survival rates.”

It may be that if we continue to improve our survival rates and do more of these screenings, we’ll see some benefit.

“The study found that more than a quarter of patients with prostate cancer had a genetic defect, and that the majority had a risk of death of 10 or more.”

I think this is a good example of the importance of screening and early detection in prostate cancer,” Dr Nevin said.

The researchers looked at a sample of patients who had been diagnosed with prostate specific antigen (PSA), a genetic marker that helps the body to recognise prostate cancer.”

The PSA was detected in nearly 20 per cent of these patients.

“But if you have a 10 per cent mutation, you’re almost three times more likely to die than someone who has a healthy mutation,” Dr Dan Jansson, the study’s lead researcher, said.

“It’s also possible that the person is more likely than the others to have a mutation in the gene for the receptor that detects PSA.”

So if you’re having the same mutation as someone who does not have the mutation, it may be the mutation that’s responsible for the increased mortality.

“In the trial, the risk was even higher for patients with more than five previous cancers.”

This is a really important finding that shows the importance that screening and getting early diagnosis can have,” Dr Jansson said.