Childbirth, tuberculosis or even just a severe stomach bug - at the beginning of the century there were many ways to die young. Now that we live into our 80s and are unlikely to be killed off by any of these, you'd think we could look forward to bridge and a glass of claret. Perhaps not, according to the latest figures published by the office of national statistics. It has reported that two in five people will get cancer, compared to one in three a decade ago.

"The proportion of people getting cancer has been going up gradually," says Dr Mike Quinn, director of the national cancer registration bureau at the office of national statistics. "The number of new cases between 1971-1996 increased by 50%. Men have just above a 40% lifetime risk of having cancer; women have slightly below this." The figures exclude skin cancers, apart from melanomas.

For both sexes there are three cancers that account for more than half the registered cases. The most common cancers for men, in descending order, are lung, prostate and colorectal cancer. For women it is breast, colorectal and lung.

Most of the rise in new cases can be accounted for by an increase in prostate cancer in men and lung cancer in women. Rates for colorectal cancer stay at around three or four per 100 people, with a small increase in men. On the plus side, cervical cancer rates have plummeted and the incidence of breast cancer remains static, after a frightening peak in 1992 when it affected nearly one in nine women. Lung cancer in men continues to fall, reflecting the fact that fewer smoke.

Cancer rates are also rising worldwide. In 1985, there were 7.6m new cases, compared to 5.9m in 1975. The estimated figure next year is 10.3m. Again, these figures exclude skin cancer (apart from melanomas), and again the most common cancers are lung, colorectal, prostate and breast.

But before we panic, this increase, both UK and worldwide, is partly due to the fact that more of us are living long enough to get cancer. "Cancer is a disease of the elderly, and as the age distribution shifts we are getting more cancers," says Quinn. "The rate of new cancers below 50 years of age remains low. If we allow for the population getting older, this accounts for 16% of the rise in cancers in men and 30% of the rise in women."

Also, cancer registration is more efficient, accounting for a further proportion of new cases. "Cancer registries have improved their procedures from 1979," explains Quinn. Some registries have clerks who trawl through hospital notes looking for cases of cancer. Some rely on information from pathology labs who will have diagnosed cancers from patients' tissues, while others hope that hospitals will inform them.

New technology, particularly in imaging techniques, has made it easier to look for cancers. "If doctors go looking for these things they tend to find more of them," says Quinn. "Also, people are more aware and look for cancers themselves - the campaign on breast awareness has made women come forward for mammography."

The rise in lung cancer in women, however, can only be explained by a predilection for smoking. This disease may not be kind enough to wait for old age. "We can predict an increase in women with lung cancer because of the current smoking rates in young female teenagers," warns Dr Denis Talbot, consultant oncologist at the imperial research fund medical oncology unit in Oxford. "The risk of lung cancer is related to the length of time that you smoke and to how much you smoke, so it is possible to develop it in middle age."

Prostate cancer's ascendancy is thought to be due to men living longer, and also to the rise in unofficial screening. "Prostate cancer frequently develops very slowly," says Dr David Dearnaley, senior lecturer at the institute of cancer research in Sutton, Surrey. "It becomes very common in men in their 70s and 80s, but varies from being a disease you see only under a microscope to one that causes symptoms and has a devastating effect on men's lives. As more men live into their 80s, more will be affected by prostate cancer." For men in their early 50s, only 12 in 100,000 will develop prostate cancer. By the time they reach their 80s, the rate is 770 per 100,000.

Screening, done by a blood test that detects levels of prostate-specific antigen, is taken up by 70% of American men. National guidelines from the department of health here do not endorse national screening, although research may soon be carried out to see if it could produce health benefits.

"In the US, between 150,000 to 200,000 new cases are diagnosed each year, and 33,000 men die annually from the disease," says Dearnaley. "While in the UK, around 16,000 are diagnosed each year, and 10,000 to 11,000 die annually. The proportion of new cases to those dying each year is very different. Once you screen, you get a peak of new cases - and the vast majority of cases in the US are diagnosed in the early stages, when they are potentially curable."

The number of new cases not accounted for by screening or ageing may be due to environmental factors, says Dearnaley. The disease is rare in China and Japan. However, Dearnaley continues, "The very early stages of prostate cancer are found in the same proportions in men of the same ages in all countries, so it may be something in the environment that causes it to progress. It is unlikely to be environmental toxins such as pollution. It is more likely to be diet."

If, as we get older, developing some form of cancer becomes increasingly unavoidable, then at least there's the hope that survival rates are improving. "We would hope that mortality rates will decline," says Dr Peter Sasieni, epidemiologist at the imperial cancer research fund. "Mortality in prostate cancer is falling, as is breast cancer, in which screening and the more widespread use of tamoxifen [a hormone treatment] have improved survival. Deaths from cervical cancer are also falling because of increased screening. You catch the cancer earlier than you would have done previously - that is, when it is more easily treated."

New therapies and ways of carrying out radiotherapy and surgery are also improving survival rates. The government has now appointed a national cancer director, Professor Mike Richards, to improve and equalise services around the country.

As more of us get cancer - and, as Sasieni points out, there are few cancers that are very rare between the ages of 80 and 100 - it may cease to be such a terrifying illness. It was certainly around at the turn of the century; it just didn't get much attention.

"There were so many other things then," says Sasieni. "A woman dying in childbirth, leaving four children, had much more impact than someone dying at 65 - although today we would think that dying at 65 was terrible."

The days when doctors used euphemistic terms, such as warts for bladder cancer, are also over. "People talk about it more openly," says Sasieni. "As more of our friends get cancer and are still around 10 years later, then our perception of the disease will change."

Around two thirds of people who get cancer will die from their disease, but many will have lived with it for a long time. "One third of people with cancer don't die of it," says Mike Quinn. "It is so many different diseases. Some are highly fatal, such as lung, liver and stomach, whereas others have very good survival rates. It is an involved picture."