CENTRE OF EXCELLENCE FOR ONCOLOGY (CANCER)

Things people do
Some cancers are caused by things people do or expose themselves to. For example, tobacco use can cause cancer of the lungs, mouth, throat, bladder, kidneys, and many other organs. Of course, not everyone who uses tobacco will get cancer, but it greatly increases a person’s risk. It increases their chance of developing heart and blood vessel disease, too.

Spending a lot of time in the sun without protection can cause skin cancer. Melanoma is a very serious form of skin cancer linked to UV light from the sun and tanning beds.

Other things people are exposed to
Radiation can cause cancer. For instance, people exposed to nuclear fallout have a higher cancer risk than those who were not exposed. Sometimes, radiation treatment for one type of cancer can cause another cancer to grow many years later. This is why doctors and dentists use the lowest possible doses of radiation for x-rays and scans (much lower than the doses used for cancer treatment).

Certain chemicals have been linked to cancer, too. Being exposed to or working with them can increase a person’s risk of cancer. Call us to learn more about the carcinogens (substances that cause cancer) that may be around you, or see the What Causes Cancer? section of our website.

Genes that run in families
About 5% to 10% of all cancers are linked to genes that are inherited from parents.

Bottom line
No one knows the exact cause of most cases of cancer. We know that certain changes in our cells can cause cancer to start, but we don’t yet know exactly how it all happens. Scientists are studying this problem and learning more about the many steps it takes for cancers to form and grow. See the “What Causes Cancer?” section of our website to learn more about the things that have been linked to this disease.

If you are interested in taking steps to help reduce your cancer risk, see the section below called “Can cancer be prevented?”

It’s a common myth that injuries can cause cancer. But the fact is that falls, bruises, broken bones, or other such injuries have not been linked to cancer. Sometimes a person might visit a health care provider for what’s thought to be an injury and cancer is found at that time. But the injury did not cause the cancer; the cancer was already there. It also sometimes happens that a person will remember an injury that happened long ago in the place cancer was found.
Rarely, burn scars can be the site of cancer many years after the burn has healed. Most often, skin cancer is the type that starts in a burn scar.

Researchers have done many studies to see if there’s a link between personality, attitude, stress, and cancer. No scientific evidence has shown that a person’s personality or outlook affects their cancer risk.
There are many factors to look at in the relationship between stress and cancer. It’s known that stress affects the immune system, but so do many other things. Despite many studies, a link between psychological stress and cancer has not been found.

A risk factor is anything linked to your chance of getting a disease, such as cancer. Different cancers have different risk factors. For instance, exposing skin to strong sunlight is a risk factor for skin cancer, but it’s not linked to colon cancer. Some risk factors can actually cause cancer, while others may simply be more common in people who get cancer. For example, old age by itself doesn’t cause cancer, but it is a risk factor.
Still, risk factors don’t tell us everything. Having one risk factor, or even many, does not mean that someone will get cancer. Some people with one or more risk factors never develop the disease, while others who do develop cancer have no known risk factors. Even when a person who has a risk factor is diagnosed with cancer, there’s no way to prove that the risk factor actually caused the cancer.
There are different kinds of risk factors. Some, like a person’s age or race, can’t be changed. Others are linked to cancer-causing factors in the environment. Still others are related to personal actions, such as smoking. Some factors influence risk more than others, and a person’s risk for cancer can change over time, due to factors such as aging or lifestyle.
Some of the major cancer risk factors that can be controlled:
    • Tobacco use
    • Diet
    • Physical activity
    • Weight
    • Alcohol use
    • Sun exposure
    • Environmental exposures, such as radon, lead, and asbestos
    • Exposure to infections such as hepatitis, HPV, and HIV

In the past, people often stayed away from someone who had cancer. They were afraid they might “catch” the disease. But cancer isn’t like the flu or a cold. You can’t catch cancer from someone who has it. You won’t get cancer by being around or touching someone with cancer. Don’t be afraid to visit someone with cancer. They need the support of their family and friends.