When Healthy People Get Cancer

Lance Armstrong may be the poster child for a seemingly highly healthy individual who develops cancer. Armstrong was a competitive athlete when he was diagnosed with advanced testicular cancer. He overcame his grim prognosis. Many otherwise healthy people are not as fortunate.

There are plenty of scary statistics about how many people contract cancer. But on the other hand: two-thirds of humans never get cancer.

Epidemiologist Devra Davis, M.D. writes that "aside from smoking, drinking, other bad habits, and some workplace exposures, most cases of cancer occur in people who have led otherwise healthy lives." There are several possible explanations for this.


According to research published in the Proceedings of the National Academy of Science, it appears evolution has favored a limited number of relatively common genes that are resistant to cancer and may stop cancer cells before they grow. The researchers write that studies of disease patterns in populations indicate a significant percent of the human population is highly resistant to cancer, while an equally significant fraction is highly susceptible. We still need to understand why some people have—or don't have—this protective mechanism.


Even healthy individuals can carry genetic mutations that increase their risk for cancer. For example, women who carry the BRCA 1 and BRCA 2 genes are more susceptible to breast and ovarian cancers. Genetic screening can identify individuals with these mutations; however, only individuals who have known or suspected risks (such as family history) are generally tested.


The increase in cancer screenings correlates with an increase in diagnosis of certain types of cancer, such a ductal carcinoma in situ (early stage breast cancer). Physician Gilbert H. Welch says some healthy people have cancers that would never cause problems, or might eventually go away, if they weren't detected through screening.

Cancer Prevention

Joseph Mercola, MD, says studies of ancient bodies find that cancer was extremely rare until recent times when pollution and poor diet became issues.

Despite any inherent susceptibility or unavoidable exposure to environmental pollution, we can all take proactive steps to reduce our risk of developing cancer. Dr. Mercola urges individuals not to wait for "definitive scientific proof" about environmental causes of cancer to incorporate anti-cancer strategies into their lives.

  • Avoid known carcinogens, such as tobacco and radiation.
  • Optimize your vitamin D levels year round through appropriate sun exposure.
  • Control your insulin levels by limiting your consumption of refined grains and sugars.
  • Get regular physical activity and adequate sleep.
  • Maintain a healthy weight.



Environmental Health Association of Nova Scotia. "Why Healthy People Get Cancer: Centre Examines Environmental Suspects." Update. Spring 2005 Web.

Klein, George. "Toward a Genetics of Cancer Resistance." PNAS 06 (3) (2009): 859-863. Web. 7 January 2009.

Mercola, Joseph, MD. "Finally, Proof that Cancer is a Man-Made Disease." Web. 3 December 2010.

Mercola, Joseph, MD. "The Coming Cancer Explosion." Web. 27 December 2008.

National Cancer Institute. "Cancer Prevention Overview (PDQ®)." Web. 24 May 2012.