Almost 50% of Cancer Deaths in US May Be Preventable, Study Finds : ScienceAlert

Modifiable risk factors, from cigarette smoking to a lack of exercise, could be responsible for close to half of the cancer-related deaths happening among US adults aged over 30 years, according to a new study that analyzed 1.78 million cases from 2019.

The message from the research, led by a team from the American Cancer Society (ACS), couldn’t be much clearer: Individually and collectively, the chances of developing cancer and dying from the disease can be significantly reduced by making simple decisions to live healthier lives, and improving access to healthcare.

“Large numbers of cancer cases and deaths in the United States are attributable to potentially modifiable risk factors, underscoring the potential to substantially reduce the cancer burden through broad and equitable implementation of preventive initiatives,” write the researchers in their published study.

In 19 of the 30 cancer types studied, more than half of cases and deaths were due to potentially modifiable risk factors.

The study authors highlighted three areas in particular where there are strong links between cancer rates and factors we can mostly control: smoking, excess body weight, and cancer-related viruses (such as hepatitis B) that can be vaccinated against.

Cigarette smoking had the largest proportion of cases attributable to it: 19.3 percent of cases overall. Excess body weight was second with 7.6 percent, followed by alcohol consumption (5.4 percent), UV radiation exposure (4.6 percent) and physical inactivity (3.1 percent).

There are always a number of complex factors at play with cancer of course, and the extent to which lifestyle choices can mitigate risk varies between cancer types.

The team found the proportion of cases caused by modifiable risk factors was 100 percent for cervical cancer, as risk can essentially be eliminated by vaccination.

Top of the list when it comes to number of cases is lung cancer: For 2019, 104,410 cases in men and 97,250 cases in women were linked to modifiable risk factors.

“This finding underscores the importance of implementing comprehensive tobacco control policies in each state to promote smoking cessation, as well as heightened efforts to increase screening for early detection of lung cancer, when treatment could be more effective,” says cancer epidemiologist Farhad Islami from the ACS.

“Interventions to help maintain healthy body weight and diet can also substantially reduce the number of cancer cases and deaths in the country.”

Genetics and environmental factors can also play a role in the likelihood of someone developing cancer. Essentially, the disease involves the uncontrolled division of cells, creating an abnormal growth that can directly damage organs or create dangerous imbalances in biological functions.

While treatment options are improving over time, and recovery rates are rising, this new study is an important reminder of just how many cancers could be prevented to begin with – through quitting smoking, watching our weight, using sun-protection measures, or drinking less, for example.

“These findings show there is a continued need to increase equitable access to preventive health care and awareness about preventive measures,” says Ahmedin Jemal, a cancer epidemiologist at ACS.

The research has been published in CA: A Cancer Journal for Clinicians.