A recent study conducted by researchers at the American Cancer Society (ACS) has revealed that around 40% of cancer cases and nearly half of all cancer-related deaths in individuals aged 30 and above in the United States (equivalent to 713,340 cancer cases and 262,120 cancer deaths in 2019) could be linked to controllable risk factors like smoking, obesity, alcohol consumption, lack of exercise, poor diet, and infections. Among these factors, smoking was identified as the primary contributor, accounting for almost 20% of all cancer cases and 30% of cancer deaths. The study’s findings were published in the journal CA: A Cancer Journal for Clinicians.
“Despite a significant decline in smoking rates over the years, the number of lung cancer fatalities connected to cigarette smoking in the US is concerning. This emphasizes the urgency in implementing comprehensive anti-smoking measures nationwide to encourage smoking cessation, as well as enhancing screening for early detection of lung cancer when treatments are most effective,” stated Dr. Farhad Islami, the senior scientific director for cancer disparity research at the American Cancer Society and the lead author of the report. “Efforts to maintain a healthy body weight and balanced diet can also significantly reduce the incidence of cancer cases and deaths in the country, especially with the rising occurrence of various cancer types associated with obesity, particularly in younger individuals.”
The study utilized nationally representative data on cancer occurrences, fatalities, and the prevalence of risk factors to estimate the percentage and number of cancer cases and deaths attributable to modifiable risks overall (excluding non-melanoma skin cancers) and across 30 different cancer types. These risk factors included smoking habits (current and past smokers), secondhand smoke exposure, obesity, alcohol intake, consumption of processed meats, inadequate intake of fruits and vegetables, fiber, and calcium, physical inactivity, UV exposure, and various infections like Epstein-Barr virus (EBV), Helicobacter pylori, hepatitis B (HBV), hepatitis C (HCV), Kaposi sarcoma herpesvirus (HHV-8), human immunodeficiency virus (HIV), and human papillomavirus (HPV).
The results highlighted that smoking was the leading cause of preventable cancer cases, contributing to 19.3% of all cases (344,070 cases) and accounting for 56.0% of preventable cancers in men and 39.9% in women. Obesity followed as the second significant risk factor (7.6%), trailed by alcohol consumption (5.4%), UV exposure (4.6%), and physical inactivity (3.1%).
When examining specific cancer types, the proportion of cases attributed to controllable risks ranged from 100% for cervical cancer and Kaposi sarcoma to 4.9% for ovarian cancer, with over 50% for 19 out of the 30 cancers evaluated. Apart from cervical cancer and Kaposi sarcoma, more than 80% of melanomas of the skin (92.2%) and cancers of the anus (94.2%), larynx (89.9%), lungs (88.2%), pharynx (87.4%), trachea (85.6%), esophagus (85.4%), and oral cavity (83.7%) were linked to evaluated risk factors. Lung cancer had the highest number of cases associated with such risks in both men (104,410 cases) and women (97,250), followed by skin melanoma (50,570), colorectal cancer (44,310), and bladder cancer (32,000) in men, and breast (83,840), uterine corpus (35,790), and colorectal (34,130) cancers in women.
“This underlines the ongoing necessity to enhance access to preventive healthcare and awareness regarding preventive measures. Effective vaccinations are accessible for hepatitis B, which causes liver cancer, and HPV, linked to various cancers like cervical, anogenital, and oropharyngeal cancers,” added Dr. Ahmedin Jemal, the senior vice president for surveillance and health equity science at the American Cancer Society and the senior author of the study. “Adhering to the recommended vaccination schedule can significantly reduce the risk of chronic infections and subsequent cancer risks associated with these viruses. However, HPV vaccination rates in the US are currently below optimal levels.”
