Changes in Cancer Screening Recommendations Cause Confusion

< Nov. 25, 2009 > -- Changes in screening recommendations for two types of cancer - breast and cervical - announced in close proximity to each other within the past two weeks have upended the world of cancer screening.

Not only did the US Preventive Services Task Force (USPSTF) just raise the age at which it recommends women get their first mammogram from 40 to 50, but the American College of Obstetrics and Gynecologists (ACOG) recommended that adolescents should be spared the inconvenience and possible risks of cervical cancer screening, and wait until they reach the age of 21 for such testing. Both groups also recommended screening less frequently.

Add to that the long-simmering debate on the value of prostate-specific antigen (PSA) testing for prostate cancer and the fact that both the American Cancer Society (ACS) and the American College of Radiology (ACR) have disagreed with the new USPSTF recommendations. Thus, many patients and even experts feel like they are suffering from a bad case of medical whiplash.

Timing of Changes Questioned

There is speculation that the timing of the announcements was more than coincidence. Clinicians and others are asking if the changes are a reflection of new science, attempts to influence the current raging healthcare debate, or just medical business as usual.

The timing, by most accounts, was purely accidental.

"I think it's a coincidence that this [the mammogram recommendation] came out when it did, right in the middle of the healthcare reform discussion. It's a good panel, one that was dedicated to getting the right answer to what should be done about this," says Dr. Robert J. Barnet, senior scholar in residence at the Center for Clinical Bioethics at Georgetown University, in Washington, D.C.

Dr. Jay Brooks, chairman of hematology/oncology at Ochsner Health System in Baton Rouge, La. adds, "This is nothing new. Cancer screening guidelines have been changing as more scientific knowledge accumulates."

Screening Guidelines Frequently Questioned

Much of the new knowledge does suggest that over-screening happens, often resulting in false-positive results, which lead to more biopsies and more angst. This is true of breast, cervical, prostate, and other forms of cancer, experts concur.

"There's appropriate screening and there is the appropriate population that should be getting that screening, and there is the appropriate screening interval," says Dr. Otis Brawley, chief medical officer of the ACS. "We can violate all of those things."

Meanwhile, false-positive results from mammographies are more common in younger (age 40 to 49) women than in the upper age bracket. And the age cut-offs for screening may be artificial.

"We like to lump people into big decades of life, so the risk of a 40-year-old woman and the risk of a 49-year-old woman [for breast cancer] are different," Dr. Brooks notes. "The risk at 40 is much less than the risk at 49."

"Younger women are at higher rates of false-positives, which results in more biopsies, more procedures being done, and women getting callbacks for extra mammograms," he adds. "This creates anxiety for something that's not anything bad."

Also, there is increasing evidence that some cancers will never turn into anything dangerous and, therefore, do not warrant treatment.

Understanding of Cancer Changes as New Knowledge Added

"Our definition of cancer was given to us by German pathologists in the 1840s after they looked at biopsies from autopsy specimens," explains Dr. Brawley. "Now, 170 years later, we've progressed in terms of imaging, in terms of medical diagnostics into what I call the genetic and molecular biologic age, but our ability to define cancer has not progressed beyond the light microscope. What we need to be able to do eventually is say that 'this cancer is never going to progress,' it is not going to spread and invade other organs in the body. But right now we don't have the molecular tools to predict their behavior."

"Not only do we need to find small tumors, we need to know more about the biology of those tumors," adds Dr. Michael V. Seiden, president and CEO of Fox Chase Cancer Center in Philadelphia.

Until those tools are developed, imperfect screening is going to lead to over-diagnosis and unnecessary treatment.

Still, there is no question that the revisions do fit into a larger and rapidly changing health-care picture.

Experts Disagree Among Themselves

According to Dr. Brawley, ACOG's new cervical cancer guidelines "look amazingly" like the 2002 American Cancer Society guidelines.

The ACS does not agree with the new USPSTF guidelines for breast cancer screening, however.

"Our view is that breast cancer screening saves lives and women aged 40 and above should get a high quality mammogram and clinical breast exam on an annual basis," Dr. Brawley says.

Dr. Brooks is not changing his advice to women. "I tell women at age 40, if she wants to begin screening with mammography, it's fine," he says. "I haven't changed what I'm recommending in my practice but I try to explain to women what the rationale behind it is."

Always consult your physician for more information.

About Cancer Screening Tests

Most cancers are easier to treat when they are found in their earlier stages. Physicians may find cancers when they are small and normally undetectable by using screening tests such as mammography, blood tests, CT scans, and other tests. Often, physicians recommend screening tests when a person shows no sign of cancer because the tests can detect cancer before symptoms develop.

Many people, however, may not realize that there are controversies surrounding screening tests. Researchers have long been debating the value of mammograms, spiral CT (computerized tomography) scans for smokers, and the PSA (prostate-specific antigen) blood test. How do physicians decide what tests should be used for screening cancer? Who should get them? How often should they be done? How many people have to be tested before one life is saved? Why are there screening tests for some, but not all, cancers?

Risks versus benefits: As with any tests, there are risks and benefits to screening tests. Benefits include finding precancerous cells before they develop into cancer (a result of regular Pap tests and colonoscopies) and finding cancer in its earlier stages when the tumor is small and contained and therefore easier to treat (a result of having a mammogram). Both of these can be done before the person even develops symptoms.

However, there are also risks, such as unnecessary and costly biopsies and treatments and wrong diagnoses. A false positive test suggests a person has cancer when he or she does not. A false negative test suggests a person does not have cancer when he or she does have it. Physicians should carefully weigh the benefits versus the risks of a screening test before suggesting that a patient have it.

Who decides what screening tests should be used? Various professional groups and organizations such as the American Cancer Society, the National Cancer Institute (NCI), the American Gastroenterological Association, and others review research studies about screening tests and make recommendations. These recommendations are reviewed and revised on a regular basis based on new information as it becomes available.

If a debate occurs about a test being used for screening, it is usually because the evidence is not as clear or strong and is open to interpretation. One of the questions that may be answered is, "How many people have to be screened over a certain period of time, and at what cost, to save one life?" The answers to these questions help guide the recommendation. Sometimes the recommendations from one group differ from another. This can cause some confusion.

Personal decisions: Should you have a screening test? It depends on a lot of factors. Age, gender, and known risk factors (family history, behaviors, or exposure to cancer-related agents) may influence a healthcare provider's recommendation for any individual. Other factors that may influence whether someone has a test include cost, access, and other concerns.

If screening tests are effective, people will be diagnosed with earlier stage cancers and deaths from those cancers will decline over time. In some cancers, like cervical and colorectal cancer, screening is achieving these goals. Greater benefits can be achieved if more people can be screened for these cancers. In other cancers, like lung cancer, progress needs to be made before there are more effective screening tools.

Always consult your physician for more information.