More than half of people born after 1960 in the U.K. may be diagnosed with some form of cancer in their lifetimes, a new estimate suggests. 

While the prediction seems alarming, the researchers say the increase is partly due to people living longer overall.

“Everyone has to die of something and the longer people live the more likely that they will have previously been treated for a serious illness,” wrote Peter Sasieni, the study’s senior researcher from Queen Mary University of London, in an email to Reuters Health.

As reported in the British Journal of Cancer, he and his coauthors estimated the lifetime risk of cancer, excluding non-melanoma skin cancer, in Britain for men and women born from 1930 to 1960.

They used data on all causes of death in the UK from 1951 through 2012 and projected causes of death from 2013 to 2060, as well as data on the number of cancer diagnoses and cancer deaths from 1971 to 2009.

For men, lifetime cancer risk rose from about 39 percent for those born in 1930 to about 54 percent for those born in 1960. Risk increased similarly for women, from about 37 percent to about 48 percent.

“I was surprised when I first calculated that the risk was just over 50 percent for people born in 1960,” Sasieni said.

Along with modifiable risk factors for cancer, such as obesity, he said people are more likely to develop cancer the longer they live.

“As we become better at avoiding dying from infections, heart disease, stroke and even road accidents so we are more likely to live long enough to get cancer,” Sasieni said.

These are actually positive results, agreed Dr. Freddie Bray of the Cancer Surveillance Section at the International Agency for Research on Cancer in Lyon, France.

“Rather little of the risk is due to an increasing cancer risk in the population,” Bray, who was not involved with the new study, told Reuters Health by email.

Also, more than half the lifetime risk for people born in 1960 comes from cancer diagnosed after age 70. In their model, almost 90 percent of men born in 1960 would be diagnosed with cancer by age 120, hypothetically, if they did not die of other causes first.

Additionally, screening tests for breast and prostate cancer catch many more cases of the disease than would have been diagnosed previously, Sasieni said.

He suspects the trends would be similar in North America, Western Europe and Australia.