A recent American Cancer Society study indicates that approximately 40% of cancer diagnoses and half of cancer fatalities among adults aged 30 or older in the United States can be linked to modifiable risk factors.
These factors, which are typically controllable by an individual, encompass smoking, excess body weight, alcohol intake, physical inactivity, diet, exposure to ultraviolet (UV) radiation, and certain cancer-causing infections, as outlined in the report published in CA: A Cancer Journal for Clinicians.
The Most Significant Modifiable Risk Factor Is Smoking
Cigarette smoking was identified as the primary modifiable risk factor, accounting for nearly 20% of all cancer cases and approximately 30% of cancer-related deaths. It was responsible for 56% of potentially preventable cancers in men and 40% in women.
“Despite the significant decrease in smoking rates over the past decades, the number of lung cancer deaths caused by cigarette smoking in the United States is alarming,” Dr. Farhad Islami, the lead author of the report, stated in a press release. “This underscores the need for comprehensive tobacco control policies in every state to encourage smoking cessation, along with increased efforts to improve early detection of lung cancer, when treatment can be more effective.”
Dr. Islami and his team utilized data on cancer incidence, mortality, and risk factors to estimate the number of cancer cases and deaths attributable to each potentially modifiable risk factor. They conducted this analysis for 30 cancer types and examined the details of these risk factors.
For instance, when assessing the impact of diet on cancer risk, they examined the consumption of red meat and processed meat, the intake of fruits and vegetables, and the amount of dietary fiber and calcium consumed.
Their findings indicated that after cigarette smoke, excess body weight was the second most significant modifiable risk factor, contributing to 7.6 percent of potentially preventable cancers, followed by alcohol consumption at 5.4 percent, UV radiation exposure at 4.6 percent, and physical inactivity at 3.1 percent.
“Interventions to help maintain healthy body weight and diet can also substantially reduce the number of cancer cases and deaths in the country, especially given the increasing incidence of several cancer types associated with excess body weight, particularly in younger individuals,” Dr. Islami said.
Lifestyle Factors Contributed to up to 100 Percent of Some Cancers
The types of cancers linked to modifiable risk factors varied. Lung cancer led in both men and women, followed by skin melanoma and colorectal cancer. For women, breast cancer, endometrial cancer, and colorectal cancer were the most attributable to modifiable risk factors. For men, urinary bladder cancer was.
Modifiable risk factors accounted for 100 percent of cervical cancer and Kaposi sarcoma cases, a type of cancer associated with HIV. Furthermore, these risk factors contributed to 4.9 percent of ovarian cancer cases.
These lifestyle-based risk factors were responsible for 50 percent of the cases in 19 of 30 different cancers, including:
- 92.2 percent of melanomas
- 94.2 percent of anal cancers
- 89.9 percent of larynx cancers
- 88.2 percent of lung and bronchus cancers
- 87.4 percent of pharynx cancers
- 85.6 percent of tracheal cancers
- 85.4 percent of esophagus cancers
- 83.7 percent of oral cancers
These findings underscore the ongoing need to enhance equitable access to preventive healthcare and increase awareness about preventive measures.