Understanding the Odds of Cancer

“Good Morning America” host Robin Roberts, 46, revealed this morning she has breast cancer. The dramatic announcement came after she did a self-examination prompted by the cancer death of ABC colleague Joel Siegel.

Siegel’s death and Roberts’ candor will certainly do a lot to remind people to pay attention to their bodies and to get cancer screenings. But they also should remind people about realities concerning the disease, most especially that you should only be screened if you have a known risk factor.

And breast cancer, despite what most women have been led to believe by advocacy groups and the news media, is not as common as you might think. It is not even the leading cause of death in women. Heart disease is; same as men. Neither is it the leading cause of cancer death in women; lung cancer is.

It is often said that the risk of a woman getting breast cancer is 1 in 8. Well, that’s true, but only if you take into account the tens of millions of females from birth to age 30, when there is virtually no risk. In the major survey on the subject, there were zero cases from age 5 to age 20, thereby lengthening the odds as you grow older.

If you make it to 40, the risk drops from 1 in 223 to 1 in 69, or 1.44 percent. Yet this is still a number based on the entire population, not on an individual person’s risk. In fact, over the next five years, a 50-year-old white woman has a 1-in-75 risk of developing breast cancer, much higher than the 1-in-98 risk of a black woman, the 1-in-107 risk of an Asian/Pacific Islander and than the 1-in-133 chance of a Hispanic woman.

As is the case in so many other important areas of American life, people are stupider than anyone.

The American Cancer Society released a study today -- not the most statistically rigorous, mind you – but informative anyway. It asked 12 questions of a representative telephone sample of 1,000 people and found they are ignorant about what does and doesn’t constitute a cancer risk.

Here are 12 myths that many people believe, including some who said they were knowledgeable about cancer:

1. The risk of dying from cancer in the United States is increasing.

2. Living in a polluted city is a greater risk for lung cancer than smoking a pack of cigarettes a day.

3. Some injuries can cause cancer later in life.

4. Electronic devices, like cell phones, can cause cancer in the people who use them.

5. What someone does as a young adult has little effect on their chance of getting cancer later in life.

6. Long-time smokers cannot reduce their cancer risk by quitting smoking.

7. People who smoke low-tar cigarettes have less chance of developing lung cancer than people who smoke regular cigarettes.

8. Personal hygiene products, like shampoo, deodorant and antiperspirants, can cause cancer.

9. Getting a mammogram, or using a special X-ray machine to detect breast cancer, can cause cancer of the breast.

10. Getting a base tan or base coat at a tanning salon will provide protection from skin cancer when you go outside in the sun.

11. Underwire bras can cause breast cancer. (They can attract lightning, however.)

12. You cannot get skin cancer from using a tanning booth.

Bottom line: If you hear news of a cancer scare or a cancer cure, be skeptical, even when it comes from a source like the American Cancer Society, which raises money. Your best bet is to look it up for free from reputable sources of news like the Associated Press, the New York Times, the Washington Post or the Los Angeles Times or from the National Cancer Institute.