Cancer Prevention — Small Choices, Big Impact

February is National Cancer Prevention Month, a time to reflect on the steps you can take to reduce your risk of cancer. A recent study from the American Cancer Society (ACS) suggests that 40% of cancer cases in the U.S. are preventable, and 44% of cancer deaths in 2025 are attributed to behaviors you can change. Cancer prevention isn’t about perfection; it’s about reducing risk where you can. Many everyday choices can influence cancer risk, but the good news is this: even small changes can make a meaningful difference.

What is Cancer Prevention?

Cancer prevention means taking active steps to reduce your risk of getting cancer — often through lifestyle choices like diet, physical activity, and avoiding harmful exposures. While prevention is not a guarantee that cancer won’t occur, it focuses on reducing risk where possible. Because cancer usually develops from a mix of modifiable lifestyle choices and non-modifiable factors, such as your genetics, there is no one-size-fits-all approach — but making changes within your control is a powerful first step.

Read on to learn more about six of these modifiable risk factors and how you could reduce your cancer risk.

1. Don’t Smoke (and Avoid Secondhand Smoke)

Cigarette smoking is the #1 preventable risk factor for cancer. Smoking was linked to 20% of all cancers and 30% of all cancer deaths in the ACS study. Cigarettes contain thousands of chemicals, at least 70 of which are known carcinogens, or cancer-causing agents. These chemicals can damage your DNA, and the buildup of DNA damage can cause uncontrolled cell growth, which underlies cancer development. They can also weaken your immune system, making it harder to kill cancer cells.

The most common smoking-associated cancer is lung cancer, which is responsible for nine out of ten related deaths in the U.S. However, smoking can also cause nearly 20 other cancers, including esophageal, breast, pancreatic, liver, and kidney cancers, among others.

And direct smoking isn’t the only cause of cancer: secondhand smoke, or breathing in smoke from cigarettes without actually smoking them, can cause cancer too. Cigarette smoke still contains the same thousands of chemicals and carcinogens that cigarettes do. Secondhand smoke primarily causes lung cancer but has also been linked to larynx, nasopharynx, and breast cancers in adults.

The risk of cancer from smoking e-cigarettes is still under investigation. However, some preliminary data suggest that while less harmful than traditional cigarettes, e-cigarettes may still carry cancer risk.

Prevention Tip!

Quitting smoking at any time significantly reduces your cancer risk. Within 5–10 years after stopping smoking, your risk of 12 types of cancers drops by half, and within 10–20 years? The risk almost resembles that of a nonsmoker. It isn’t about the years you spent smoking, but the years you get back once you quit. No matter how long you’ve smoked, quitting at any time provides real, measurable benefits.

2. Alcohol: Less Is Better

Smoking isn’t the only lifestyle factor linked to cancer risk — alcohol consumption also plays a significant role. In addition to other ways alcohol consumption can be detrimental to our health, it contributed to 5.4% of cancers in the ACS study. Even at low levels, alcohol consumption can increase cancer risk and is linked to mouth, throat, esophageal, liver, and breast cancers, among others.

Alcohol can increase your cancer risk in several ways: it can disrupt cell cycles, damage your DNA, cause chronic inflammation, and increase cancer-causing hormones. It can also help cells in the mouth absorb carcinogens; for example, if you smoke and drink at the same time, it can increase the absorption of carcinogens from the cigarette.

Every year, about 20,000 adults in the U.S. die from alcohol-associated cancers, and it’s estimated that most of these deaths are avoidable with modified alcohol intake. Following guidance from health organizations like the U.S. Centers for Disease Prevention and Control (CDC), limiting alcohol can help lower cancer risk, but no amount of alcohol reduces risk as much as not drinking at all.

Prevention Tip!

Switch up the normal cocktail with a mocktail, and dedicate days to be alcohol-free. If you currently don’t drink, don’t find a reason to start.

3. Maintaining a Healthy Weight & Staying Active

Beyond smoking and consuming alcohol, overall physical health and activity levels also influence cancer risk. Excess body weight was the second-most preventable cause associated with cancer development (7.6% of cases), and physical inactivity accounted for 3.1%.

These factors can contribute to the development of stomach, endometrial, esophageal, and kidney cancers.

While researchers are not exactly sure why body weight increases the risk of cancer, it is thought that it can contribute in three ways: by creating a state of chronic inflammation, disrupting hormone balances (such as insulin), altering immune function, and affecting cell growth signals. Excess fat tissue isn’t inert; it regularly releases inflammatory signals, called adipokines, that can create a pro-cancer environment.

Reducing your risk when it comes to physical activity and body weight is not about focusing on appearance, but rather on health. Physical activity, even walking, can help regulate hormones and inflammation and reduce body weight.

Prevention Tip!

Every movement counts! Walking, gardening, and dancing all count as physical activity. Start small, do what feels comfortable, move as you are able, and do what you enjoy.

4. Eat for Prevention (Not Perfection)

The saying is you are what you eat—that may not be totally true, but what you eat definitely has health implications, including cancer risk. The ACS study found that dietary habits, such as not eating enough fruits and vegetables, low dietary calcium and fiber intake, and consumption of processed foods and red meat, are associated with a variety of cancers, including those of the oral cavity, pharynx, esophagus, and colorectum.

Lack of a balanced, healthy diet can contribute to cancer development. Consumption of processed foods and red meats can lead to obesity, chronic inflammation, and DNA damage, all of which raise cancer risk. Limiting intake of these foods and including more fruits and vegetables in your diet can help reduce your risk of developing cancer.

Prevention Tip!

The goal for dietary changes is not to be perfect, but to make manageable changes that support a healthy lifestyle and lower cancer risk. Less processed food and more fruits and vegetables are small changes that can have a big impact on your risk.

5. Sun Safety Matters

Ultraviolet (UV) exposure is another risk factor for skin cancer, accounting for 4.6% of preventable cancer cases. UV radiation can damage your DNA, leading to uncontrolled cell growth. Sun exposure includes natural sunlight, as well as UV exposure from tanning beds.

Luckily, taking steps to minimize sun exposure and protecting your skin from the sun are manageable and very doable.

Prevention Tip!

ALWAYS apply sunscreen to exposed skin anytime you’re outdoors — even on cloudy days or in winter. UV radiation can still come through the clouds. Avoid tanning beds, seek shade when possible, and wear UV-protective clothing.

6. Vaccines & Screening: Prevention Tools You Might Not Expect

Two of the most powerful — and often unexpected — tools for cancer prevention are vaccination and routine screening.

Several viruses can cause cancers, including human papillomavirus (HPV), which causes cervical cancer, and hepatitis B (HBV), which can cause liver cancer. Vaccines against HPV and HBV are incredibly effective at preventing these types of cancers from ever developing.

Screening for cancer can catch it early—or prevent it entirely. Catching cancer early increases the chances of treatment success and survival rates. Not all cancers have screening guidelines, and guidelines may differ depending on certain risk factors. See the 2026 ACS Facts and & Figures to understand screening guidelines, and talk with your health care team about what might be right for you.

Prevention Tip!

Talk to your doctor about what screening schedules and vaccines are right for you.

Progress Over Perfection: Bringing It All Together

All of the factors that can cause cancer can sound overwhelming. But there are manageable, small steps that can be taken to help reduce your risk. Every step counts, and every step helps. Prevention is a lifelong journey, but one that can be managed.

And talk to your doctor about the right paths for you and the small steps you can start taking today to reduce your risk.