Nearly 6 million deaths from five common cancers were avoided through prevention, early detection and better treatments, a new study reveals.

Biostatistician Katrina Goddard from the National Cancer Institute in Bethesda, Md., and colleagues used statistical modeling to estimate how many lives would have been lost in the United States to each of the five cancers if survival rates had remained at 1975 levels, before major advances in cancer control strategies were implemented. The team also calculated how many deaths were avoided by improvements in prevention measures, screening and treatments.

Of the 5.9 million cancer deaths averted from 1975 through 2020, 80 percent were avoided thanks to screening and prevention, the researchers report December 5 in JAMA Oncology.

Some specific highlights:

• About 3.45 million lung cancer deaths were avoided, almost entirely because of smoking cessation.
• All of the 160,000 cervical cancer deaths avoided were due to Pap testing and human papillomavirus screening. (The model did not include cervical cancers prevented by the HPV vaccine, which is reducing deaths among young women (SN: 11/27/24).)
• Better treatments accounted for 75 percent of the more than 1 million avoided breast cancer deaths. The remainder were from mammogram screening.
• Of the 940,000 averted deaths from colorectal cancer, most (79 percent) were caught early or prevented by removal of polyps during colonoscopy screening. Better treatments were responsible for avoiding 21 percent of colorectal cancer deaths.
• Screening prevented 56 percent of prostate cancer deaths, while new treatments averted the other 44 percent.

Still, not enough people are getting screened or adopting cancer-prevention measures, such as quitting smoking. “There’s opportunity to improve the uptake of these strategies,” and to develop new treatments, early detection methods and ways to avoid getting cancer in the first place, says Goddard, who directs NCI’s Division of Cancer Control and Population Sciences. “We should definitely consider the whole cancer-control continuum when we’re thinking about how to reduce the burden of cancer.”