Cancer prevention efforts—including cancer screening, vaccination, tobacco control, healthy eating, and physical activity—remain key to reducing the effect of cancer and improving outcomes across communities worldwide. In fact, researchers estimate that 50% of cancer cases and deaths in the United States could be prevented if people adopted simple healthy lifestyle choices that include avoiding smoking and alcohol, maintaining a healthy weight, and exercising regularly.19
The top three causes of cancer-related death in low-resource countries—liver cancer, stomach cancer, and cervical cancer—are largely preventable through screening or vaccination. In higher-resource countries, two leading causes of cancer-related deaths—lung and colorectal cancer—can be lowered through lifestyle changes, such as increased physical activity and avoidance of alcohol, tobacco, and processed meat. The same healthy habits can help prevent dozens of other cancers. Emerging research suggests that human papillomavirus (HPV) vaccination, mainly used for the prevention of cervical cancer, may also help reduce head and neck cancers by lowering oral HPV infections.20 Finally, safe sun exposure practices and avoidance of indoor tanning can substantially lower the risk for melanoma.
Avoidable Cancer Risk Factors: E-Cigarettes May Spur Increases in Smoking
In 2017, two federally funded studies provided the clearest estimates of how e-cigarette use may lead to a future habit of smoking cancer-causing traditional tobacco cigarettes. The first study found that people 14 to 30 years of age who used e-cigarettes were 3.6 times more likely to begin smoking traditional cigarettes than those who never used e-cigarettes (this study was funded, in part, by grants from the NCI, the FDA, and the National Institute on Drug Abuse).21 These findings indicate that e-cigarettes are not merely a substitute for traditional cigarettes, but are also a strong risk factor for future smoking. In fact, experts caution that e-cigarette use may lead to an upsurge in smoking prevalence in the long term.
Another study found that, among US teenagers 12 to 17 years of age, the rate of e-cigarette use is already approaching the rate of tobacco cigarette use; 3.1% smoked e-cigarettes compared with 4.6% who smoked tobacco cigarettes in the last 30 days (this study was funded, in part, by grants from the National Institute on Drug Abuse, NIH, and the FDA).22 However, among adults, e-cigarette use still lags far behind tobacco cigarette use (6.7% v 22.5%). In addition, among those who used more than one tobacco product, 15% of teenagers and 23% of adults used both e-cigarettes and traditional cigarettes.
There is clear evidence that e-cigarettes, smokeless tobacco, and water pipes may cause serious health problems, including cancer. Because of these potential health risks, the FDA began regulating these products, along with other tobacco products, on August 8, 2016. The US Centers for Disease Control and Prevention calls on the public, including parents, health care providers, and teachers, to discourage e-cigarette use among youth. ASCO’s Cancer.Net provides information on the risks of e-cigarettes and smokeless tobacco.
Almost one half (49%) of Americans believe that the government should spend more money on cancer prevention, and 54% think the government should spend more to help Americans afford cancer screenings and care (ASCO’s National Cancer Opinion Survey, 2017).
Avoidable Cancer Risk Factors: Indoor Tanning
UV radiation exposure from indoor tanning is a cause of malignant melanoma. Characterizing the risk of melanoma associated with use of UV radiation-emitting devices is critical for developing policies that reduce the use of such devices, but much of the evidence on this topic has come from case-control studies. In the past year, a large, prospective study was reported that adds new weight to such policy efforts, finding that the risk for melanoma rose with an increasing number of indoor tanning sessions.23 Compared with those who never used indoor tanning, women who started indoor tanning before 30 years of age had a 30% higher risk for melanoma, which suggests that the harmful effects of indoor tanning are greater at a younger age. For more information on risk factors for melanoma, visit Cancer.Net.
ASCO Issues Statement on Alcohol as it Relates to Cancer Prevention
In 2017, ASCO issued a statement on alcohol and cancer aimed at drawing attention to alcohol consumption as a contributing factor to the overall cancer burden.24 ASCO cites between 5% and 6% of new cancer cases and deaths globally as being directly attributable to alcohol. This is particularly concerning as 70% of Americans do not recognize drinking alcohol as a risk factor for cancer, according to the National Cancer Opinion Survey, conducted by ASCO in 2017.
Because drinking alcoholic beverages is a potentially modifiable risk factor for cancer, it can be targeted with preventive interventions at both the policy and individual levels to reduce the incidence of cancer. The evidence-based policy recommendations to reduce excessive alcohol consumption listed in the statement, which was published in Journal of Clinical Oncology, are:
- Provide alcohol screening and brief interventions in clinical settings;
- Lower the number of alcohol retailers per capita;
- Increase alcohol taxes and prices;
- Maintain limits on days and hours of sale;
- Enhance enforcement of laws that prohibit sales to minors;
- Restrict youth exposure to advertising of alcoholic beverages;
- Resist additional privatization of retail alcohol sales in communities with current government control;
- Include alcohol control strategies in comprehensive cancer control plans; and
- Support efforts to eliminate the use of “pinkwashing” to market alcoholic beverages (ie, discourage alcoholic beverage companies from exploiting the color pink or pink ribbons to show a commitment to finding a cure for breast cancer) given the evidence that alcohol consumption is linked to an increased risk of breast cancer.
In addition, not only does excessive alcohol consumption cause cancer, it also can delay or negatively affect cancer treatment. Oncologists are uniquely positioned to identify strategies to help their patients reduce alcohol use; address racial, ethnic, gender, and sexual orientation disparities that may place these populations at increased risk of cancer; and serve as community advisors and leaders to raise awareness of alcohol as a cancer risk behavior.
The link between alcohol use and cancer treatment is one of the most-needed areas for future research in the oncology community, particularly in studying the effect of alcohol consumption while undergoing cancer treatment, including chemotherapy, radiation, and surgery. Other underexplored research areas include the effect of alcohol consumption on postoperative morbidity and targeted therapies, such as immunotherapy and radiation. By increasing the community’s knowledge of the ways in which alcohol affects cancer and cancer treatments, oncologists and researchers may have a better understanding of its role in disease progression and therapeutic responsiveness and toxicity.