Few words are as unnerving as "cancer." It’s the mantra of hypochondriacs everywhere and the word we never want to hear issued from our doctor’s lips. But many of us take solace in the fact that we live in a time of high-tech tests and screenings. We can submit ourselves to any number of scopes, scans and swabs that strip away the mystery to assuage our fears. And awareness groups, the media, and our doctors remind us of this regularly with recommended screening schedules. Because really, what do we have to lose?

According to a new in-depth evaluation by Consumer Reports, the answer is counterintuitive. The consumer watchdog group contends that the idea of having "nothing to lose and everything to gain" from being screened for cancer simply isn’t true.

“When it comes to screening, most people see only the positives,” says Dr. Otis Brawley, chief medical officer of the American Cancer Society. “They don’t just underestimate the negatives; they don’t even know they exist.”

Dr. H. Gilbert Welch, a professor of medicine at the Dartmouth Institute for Health Policy and Clinical Practice in Lebanon, N.H., backs up that opinion. “The medical and public-health community has systematically exaggerated the benefits of screening for years and downplayed the harms,” he says.

For the latest investigation, Consumer Reports researchers moved the vacuum cleaners and cameras to the side and evaluated copious amounts of research, consulted medical experts, surveyed more than 10,000 readers, and talked with patients. They found that “too many people are getting tests they don’t need or understand, and too few are getting those that could save their lives.”

They conclude that many patients, and even some doctors, are confused about cancer screening. Most patients do what their doctor recommends, but health care providers don’t always agree on which tests are necessary. In fact, they note, research suggests that advice often varies among medical practices.

Of course, for some tests and patients, the benefits do outweigh the risks; but for many other screenings and tests, magazine researchers found that the line between benefit and risk is not so clear-cut. For example, the risks of prostate-cancer screening probably outweigh the benefits for most people. For every 1,000 men between 55 to 69 screened for prostate cancer every one to four years, the data looks like this: Zero to one prostate-cancer deaths were prevented; yet three serious complications were caused by treating the cancer, including death, heart attacks, and blood clots in the legs or lungs; and 40 men became impotent or incontinent from treatment complications. The chance of being the one case in which screening prevented death is likely to lead men to still want the test performed, but the risks are surprising.

“Cancer turns out to be a much more complicated and unpredictable disease than we used to think,” says Virginia Moyer of a task force working on these issues. “And the tests we have available to us don’t work as well as we’d hoped, and can even cause harm.”

She added, “Scientific evidence shows that some cancer-screening tests work, and people should focus on those tests rather than on screening tests that are only supported by theories and wishful thinking."

The ratings reveal that screening tests for cervical, colon, and breast cancers are the most effective tests available, for people of certain ages. But they recommend that “most people shouldn't waste their time on screenings for bladder, lung, oral, ovarian, prostate, pancreatic, skin, or testicular cancers.”

That said, the ratings are for people who are not at high risk; and those who are or who show signs or symptoms of cancer should consult with their doctor about getting appropriate tests. For the rest of us, even knowing the risks involved in cancer tests, are we able to turn off our inner hypochondriacs and skip the screenings? Human nature suggests that although the risks may outweigh the benefits in many cases, the fear of cancer may trump the logic.

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