Preventing Cancer: The Essential Guide

February 26, 2025

Happy black doctor using touchpad and communicating with a senior couple while visiting them at home

According to the International Agency for Research on Cancer, 20 million people across the globe learned they had cancer in 2022. By 2040, the number of new diagnoses in a single year is expected to reach nearly 30 million. Can anything slow the growth of cancer in America and beyond? Possibly.

“In the past, cancer care focused on diagnosis and treatment,” says Melissa Frey, M.D., M.S., associate professor in the Division of Gynecologic Oncology and director of the Genetics and Personalized Cancer Prevention Program at Weill Cornell Medicine. “Today, there is a growing interest in cancer prevention.”

If you’re interested in reducing your cancer risk, learn about a few steps you can take to get started.

Take Control of Your Health

Preventing cancer takes effort, and it starts with you. By taking your health seriously, you feel better, look better and lower your cancer risk. In fact, the American Cancer Society found that lifestyle choices are linked to approximately four in 10 cancer cases. So, if you want to help lower your cancer risk, make healthy choices, one day at a time.

Here are some healthy choices that increase your odds of remaining cancer-free.

Stop Smoking

Smoking is at the root of many cancers. From your mouth to your lungs to your bladder and beyond, smoking can cause cancer to form. This is largely due to the chemicals inside cigarettes. Of the thousands of chemicals in cigarettes, some weaken your immune system and make it harder for your body to kill cancer cells. Others actively can cause cancer to form.

A few chemicals found in cigarettes include:

Arsenic. Also used to preserve wood, arsenic is linked to liver, bladder, skin or lung cancer.
Cadmium. This metal, which helps make batteries, may lead to lung cancer and has been associated with prostate and kidney cancers.
Formaldehyde. A preservative that also helps make other chemicals, formaldehyde causes leukemia and other cancers.

Stop smoking today, and the benefits start immediately. Within five years, your risk for specific cancers drops 50 percent.

Because it can be difficult to stop, you may want to seek out smoking cessation counseling. To make the most of quitting, stay away from smoky environments, as secondhand smoke is also cancerous.

Eat a Healthy Diet

Adding more fruits, vegetables and whole grains can help you prevent cancer. Additionally, get added protection with these dietary modifications:

Add fatty fish to your meal rotation. Salmon, tuna and other fatty fish contain omega-3 fatty acids, which reduce your colorectal cancer risk. For a fish-free option, give walnuts and flaxseed oil a try.
Go light on alcohol. In a single day, men should drink no more than two 12-ounce beers, two 5-ounce glasses of wine or two ounces of spirits in a single day. Women should drink no more than half that much.
Eat less meat. Specifically, limit the amount of processed meat and red meat you eat. Doing this reduces your risk of cancer.
Get your vitamins. Calcium, vitamin D and other vitamins help reduce the risk of colorectal cancer. A well-rounded diet should fulfill all your vitamin and mineral needs. If not, you may benefit from supplements. Your provider can help determine what supplements to consider.

Exercise 150 Minutes Each Week

A growing amount of research indicates that sitting increases the likelihood of developing cancer. Exercise is a great way to offset your sedentary moments. Two ways exercise helps prevent cancer are:

Helping your body regulate cancer-causing hormones
Strengthening your immune system

Try to get at least 150 minutes of moderate-intensity exercise every week. For those days when you push it a bit harder, working out for 75 minutes at a vigorous intensity gives you the same benefit.

Reach a Healthy Weight

Being overweight is linked to an increased risk for developing cancer. However, with regular exercise and a healthy diet, you can reach and maintain a healthy weight. This is particularly beneficial, as being overweight or obese may raise your risk of developing various types of cancers, including:

Breast
Colon
Kidney
Liver
Ovarian
Prostate
Thyroid

To lose weight and keep it off, you need a personalized approach that fits your lifestyle. At the Comprehensive Weight Control Center at Weill Cornell Medicine, a team of experts works with you to identify the source of your weight issue. They then create a plan tailored to your needs.

Get Screened

Timely screening helps detect common cancers in their earliest, most treatable stages. Screenings you should talk with your provider about include:

Colonoscopy. Men and women with average risk for colorectal cancer should have their first colonoscopy by age 45 to detect colorectal cancer.
Lung screening. Those with a history of smoking who are at least 50 years old should consider lung cancer screening.
Mammogram. Women of average risk for developing breast cancer should undergo an annual breast cancer screening, starting at age 40.
Pap tests. Starting at age 21, women should have this screening for cervical cancer. You may also want to get tested for human papillomavirus (HPV) starting at age 30.
Prostate-specific antigen (PSA) test. This simple blood test detects high levels of the PSA protein in men, which may indicate prostate cancer.
Skin exam. Looking for suspicious spots or moles helps detect skin cancer and precancerous areas.

Consider Genetic Testing

Lifestyle choices aren’t the only cause of cancer. In some cases, you may inherit an increased risk of cancer.

“We now know that between 1 and 5 percent of the general population have a genetic predisposition to certain cancers,” says Ravi Sharaf, M.D., M.S., director of Genetics and Personalized Cancer Prevention, associate professor of Medicine (Gastroenterology) and associate professor of Population Health Sciences (Epidemiology) at Weill Cornell Medicine. “Testing for such genetic predisposition allows us to tailor medicine and preventive steps to your specific risk.”

Knowing about a genetic mutation can help you and your family make appropriate screening and treatment choices in the future. However, genetic testing isn’t for everyone.

Genetic testing can help you prevent cancer or find the most effective treatment if you’ve been diagnosed with any of the following:

Colorectal cancer at a young age (49 or younger)
Male breast cancer
Ovarian cancer
Pancreatic cancer
Prostate cancer that spreads to other areas
Triple-negative breast cancer

To find out if you should consider genetic testing, talk with your provider.

“Until genetic risk assessment becomes the standard of care, the responsibility falls on every individual to advocate for themselves,” Dr. Frey says. “Find a clinician with expertise in the field of cancer genetics and ask if testing is right for you.”

Need help managing your cancer risk? Find a doctor at Weill Cornell Medicine for personalized cancer prevention tips and ongoing care.