What are the Top Causes and Risk Factors for Developing Cancer?

Top Risk Factors to Consider in Reducing Your Risk of Getting Cancer.

Cancer research laboratory, male scientist studied cells under the microscope
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What are the most important causes and risk factors for developing cancer?  Most people don't realize that cancer is preventable in many cases. Learning what causes cancer and what the risk factors are is the first step in cancer prevention. Many cancer risk factors can be avoided on the one hand, or changed in another, to reduce your risk.

What are the Top Causes and Risk Factors for Cancer?

As with many things in life, our perceptions of what is a risk for cancer, and what is really a risk don't always coincide.

  Can wearing deodorant cause breast cancer?  Do underwire bras cause cancer?  Unfortunately, many of these discussions go on while people are innocently exposed to known causes of cancer.


According to the National Cancer Institute, smoking causes 30% of all cancer deaths in the U.S. and is responsible for 87% of cases of lung cancer. Not only does it affect the lungs, but smoking increases the risk of many cancersQuitting smoking immediately decreases your risk factor for cancer.

Physical Activity/Exercise

Exercising at least 30 minutes a day, 5 days a week greatly reduces your cancer risk. Exercise like yoga, aerobics, walking and running are great activities to lower your risk. Not only is physical activity important in preventing cancer on its own, but it reduces the risk of obesity - and obesity is a leading cause of cancer. You don't need to run marathons.  It's been found that even light exercise -- such as working in the garden a few days a week - reduces the risk of lung cancer among others.

Your Genes

Genetics can play a big role in the development of some cancers.  If you have a family history of cancer, such as breast cancer, taking extra precautions is vital. When cancer is genetic, a mutated gene may have been passed down. Genetic tests are available for some hereditary cancers. Keep in mind that if you have a family history of cancer, it does not mean you will develop it.

You only have a greater chance of developing it (a genetic predisposition.)

Environmental Exposures

Your surroundings can raise your risk of developing cancer.  Exposure to asbestos, a group of minerals found in housing and industrial building materials can cause a variety of medical problems, such as mesothelioma - a cancer of the lung lining.  Studies have shown that people who are exposed to high amount of benzene are at risk for cancer. Benzene is a chemical found in gasoline, smoking, and pollution.  There are many other substances in our environment that could put you at risk.  Be careful with chemicals in your home, and always take time on the job to read the information provided about the chemicals you work with.

Unsafe Sex

Practicing unsafe sex can increase your risk of developing a virus called human papillomavirus - HPV. HPV is a group of over 100 viruses.  Not all strains of HPV cause cancer, but some strains increase your risk for cervical, anal, vulvar and vaginal cancer.   Recent studies suggest that HPV also plays an important role in many head and neck cancers, and research is ongoing looking at its possible role in other cancers as well.

Sun Exposure

Skin cancer may be caused by excess exposure to UV rays from the sun.  Many people don't realize that a sunburn -- even a tan -- is actually the result of skin damage caused by the sun.  Many cases of skin cancer can be prevented through a little planning.  Wearing sunscreen can help, but practice safe sun exposure as well.  Avoid direct sunlight mid-day (from 10 am to 2 pm,) sit under an umbrella, wear protective clothing, and don't forget sunglasses to protect your eyes.  One form of skin cancer - melanoma - has a tendency to affect the eyes.  A discussion of sun exposure isn't complete without bringing up vitamin D.  Vitamin D is a vitamin which acts more like a hormone in the body, and is manufactured in our skin via sun exposure.  It's been found in recent years that a vitamin D deficiency - something that affects over half of U.S. citizens - is a risk factor for many types of cancer.  That doesn't mean you should throw away the sunscreen, especially since a simple blood test can tell you if you are deficient or not.  Ask to have a level checked at your next physical exam.


National Cancer Institute. Risk Factors for Cancer. Updated 12/23/15. http://www.cancer.gov/about-cancer/causes-prevention/risk

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