One in two people will develop cancer at some point in their lives and the UK faces a crisis if the NHS does not plan ahead, according to the latest forecast.

The new figure, which replaces the previous of one in three, is the most accurate forecast to date from Cancer Research UK.

The charity said it highlights the urgent need to bolster public health and NHS cancer services so they can cope with a growing and ageing population and the looming demands for better diagnostics, treatments and earlier diagnosis.

It added there will "never be one single magic bullet" to cure all cancers and age is the biggest risk factor for most forms of the disease.

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."

He said "better planning and innovative design of services" are needed, adding: "We also need to ensure the health service is adequately funded if we're to deal effectively with the growing burden of cancer and offer all patients the best chance of long term survival."

The new research was calculated using a different method to the one used to determine the one in three figure, with researchers claiming it is more accurate.

The lifetime cancer risk for women (47.55%) is lower than that of men (53.5%), while the combined lifetime risk is 50.5%.

While the biggest risk factor is age, other lifestyle factors include smoking, obesity, diet, tanning and sunburn, overdiagnosis, lack of exercise and child-bearing patterns.

However, the UK's cancer survival has doubled over the last 40 years and around half of patients now survive the disease for more than 10 years.

Mr Kumar added that the single biggest thing that affects whether a patient is cured is whether their disease is caught early enough.

He said: "We know that too many cancers are diagnosed very late and once they're more advanced it becomes much harder to cure. We can treat them, we can extend life but it becomes much harder to cure if we're catching the cancers very late."

Research author Professor Peter Sasieni, based at Queen Mary University of London, added: "Cancer is primarily a disease of old age, with more than 60% of all cases diagnosed in people aged over 65. If people live long enough then most will get cancer at some point."

Prof Sasieni said breast cancer is the most common form in women, prostate cancer is the most common form in men, and bowel cancer and lung cancer are common in both sexes.

He said rates of cancer of the oesophagus are "increasing rapidly" while stomach cancer is now "far less common".

James Jopling, director for Scotland at Breakthrough Breast Cancer, said: "This new figure underlines the importance of prevention and early detection of all cancers including breast cancer in order to prevent patient suffering.

"Cancer is not a done deal and with breast cancer the most common cancer among women in Scotland, these statistics bolster us in our aim to not only stop people dying from this disease but, importantly, to also focus on stopping it developing in the first place. Prevention must be seen as important a weapon as treatment in the fight against breast cancer."