Common knowledge suggests that everyone should be tested for cancer. But for healthy people, that may not be the case, according to Dartmouth Medical School professor Dr. H. Gilbert Welch in his recently published book "Should I Be Tested for Cancer: Maybe Not and Here's Why."
"The main thing I wanted to get across to the general public is that cancer testing is a two-edged sword," Welch said.
While the benefits of cancer testing are well-known, Welch said that the medical community is more aware of the downsides of tests than the general public. Most of the messages heard by the public overemphasize the possible benefits and do not mention the problems created for some people.
One of the main issues is that cancer testing can be wrong, especially in a general screen of the population. If the test is highly sensitive, then it is possible for some people to be falsely diagnosed with the disease. A diagnosis is most likely followed by more invasive testing and definitely in an increasingly traumatic experience. Mammograms and PSA tests for prostate cancer are two tests two which this applies.
"And yet doctors will say it's never to late to get a baseline," said psychology professor George Wolford.
But this only applies to healthy people, Wolford said. Once there are symptoms present, people should be tested for cancer and subsequently treated.
It is not always better to know if you have cancer, Welch added. There are many cancers that will throughout your life never bother you, and knowing that the cancer is there will only cause unnecessary worry. Pathologists may find small abnormalities that they call cancer, but they either don't grow or grow so slowly that people will die from something else before the cancer causes problems.
When those cancers are found, treatment will be the likely next course of action, and cancer surgery, chemotherapy, and radiation can all cause real harm to patients.
"While these risks are acceptable for cancers destined to cause problems, there is no reason to accept them for cancers that will never cause problems," Welch said.
"The question becomes one of balancing the risk that the cancer will become a problem against the risks of treatment."
There are some people that should be tested for cancer, though, Welch said -- those at a high risk for cancer and a low risk to die from something else have the most to gain from testing.
Ultimately, Welch said, testing is a personal choice, based on what a person wants from medicine. Some want to know everything that could be wrong with them and others have more of a focus on health and do not want to think at all about what could happen to them.
"However you choose to live, it's worth thinking about carefully because we are rapidly approaching a point when we can find something wrong with everybody if we look hard enough," Welch said.
