One in two people in the UK will get cancer at some point in their lives, according to the latest forecast by experts.
Cancer Research UK announced the new figure - which replaces the longstanding previous estimate of one in three - as it warned the country faces a "crisis" if it does not plan ahead.
The charity says the increase in cases is largely attributed to people living longer, but that the number of people surviving the disease has never been higher.
Professor Peter Sasieni, from Queen Mary University of London, is the author of the study published in the British Journal of Cancer that produced the figure.
"Cancer is a disease of old age," he said.
"The longer you live the more likely you are to get cancer and we think two thirds of the increase is because of increased longevity, the other third is because cancer rates are actually increasing."
While Cancer Research UK said there will "never be one single magic bullet" to cure all cancers, it called for a boost to public health and the NHS to meet looming demands for better diagnostics, treatments and earlier diagnosis.
The country's cancer survival rate has doubled over the last 40 years and around half of patients now survive the illness for more than 10 years.
The lifetime cancer risk for women (47.55%) is lower than that of men (53.5%), while the combined lifetime risk is 50.5%.
In 1980 the combined risk was 27.2%, in 1990 it was 32.7%, in 2000 it was 37.1% and in 2010 it was 41.8%.
Harpal Kumar, Cancer Research UK's chief executive, said: "We're living longer and that means we're more likely to develop a range of age-related health issues.
"We need to plan ahead to make sure the NHS is fit to cope. If the NHS doesn't act and invest now, we will face a crisis in the future - with outcomes from cancer going backwards.
"There will never be one single magic bullet that treats ... cures all cancers.
"I cannot foresee a time when that's going to be the case. But already we're able to cure a number of cancers now."