Weight loss in patients over the age of 60 should be urgently investigated, with one in seven cases among men likely to mean cancer, a major study has found.

The research by Oxford University found that losing weight is the key symptom of the disease, linked to at least 10 types of cancer.

Experts called on GPs to refer patients with unexplained weight loss for urgent tests, in a bid to speed up diagnosis.

Britain’s survival rates are lagging behind may comparative countries, with the UK falling in the bottom half of international league tables for seven major forms of the disease.

Unexplained weight loss has long been associated with cancer.

But Tuesday’s research, involving more than 11 million patients, is the first major study to quantify the association.

Overall it found that among those over 60, men with unintended weight loss had a 14.2 per cent risk of cancer, with a 6.7 per cent risk found among women of the same age.

Experts said the higher rate among men was found because weight loss was closely linked to prostate cancer, the most common cancer in men.