Screening

[Mtngrl]

From Medpage Today:

Change Screening Attitudes, Cancer Researcher Says

By Nancy Walsh, Staff Writer, MedPage Today
Published: November 25, 2011
Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco.

Action Points

• A researcher believes that the time has come for a fundamental shift in attitude toward cancer screening, with greater emphasis on providing the public with information about absolute risks and the potential for harm associated with screening.
  
• It was recommended that patients and the public should be given clear information -- based on science rather than opinion or advocacy -- that explains cancer incidence and mortality, and provides transparent information about the risks and benefits of screening.

The time has come for a fundamental shift in attitude toward cancer screening, with greater emphasis on providing the public with information about absolute risks and the potential for harm associated with screening, according to a behavioral oncology researcher.
The firestorm that erupted after the U.S. Preventive Services Task Force recommended against mammograms for women ages 40 to 49 was emblematic of the controversies generated among healthcare providers, the public, and advocacy groups every time new guidelines are announced, according to Michael Edward Stefanek, PhD, of Indiana University in Bloomington.
A perspective that is unappreciated is that at least 1,900 women in their 40s would need to undergo mammography to avoid one death over 11 years. During that follow-up time, there would be 2,000 false-positive tests, "along with the resulting unnecessary biopsies, overdiagnosis, and overtreatment," Stefanek explained in a commentary in the December 20 issue of the Journal of the National Cancer Institute.
Even routine mammography for women ages 50 to 70 -- a recommendation that has not been seen as controversial -- has considerable opportunity for harm, with 838 women having to be screened during six years to prevent a single death from breast cancer.
And among women in their 50s, five in 1,000 can be expected to succumb to breast cancer during a ten-year period, but annual screening during that time would only prevent one of those five deaths. Nearly 1,000 women "screened for ten years will have gained nothing, and may have been subject to as many as 50% false-positive tests, unnecessary biopsies, overdiagnosis, and overtreatment for breast cancer," he argued.
The public has not been well served by policy makers and institutions that have taken the approach of emphasizing the benefits of cancer screening, particularly in reducing mortality, and downplaying the consequences, particularly of unnecessary treatments, he stated.
"There will come a time when all the patients have been followed, all the analyses done, all the groups assembled, and all the editorials written, and we still will not be secure in our knowledge of the individual harms and benefits of cancer screening. It appears that this time has come," wrote Stefanek, who has previously held positions at the National Cancer Institute and the American Cancer Society.
The evidence for prostate cancer screening also is ambiguous. For instance, one study that included 20,000 men who had prostate-specific antigen (PSA) testing every two years or no screening found a decrease in deaths from prostate cancer of nearly 50% with the test over 14 years.
Yet a meta-analysis that included almost 400,000 men found no improvement in either overall mortality or prostate cancer-specific deaths.
Moreover, a randomized trial determined that 1,410 men would have to undergo screening and 48 cancers treated to prevent a single prostate cancer-related death, according to Stefanek.
And for the more recent notion of screening smokers for lung cancer using CT scans, the potential harms associated with screening have been clearly demonstrated by the finding that about 95% of positive screens were, in fact, false positives.
To address these concerns, Stefanek offered a number of possible strategies.
An important shift must emphasize the education of healthcare providers and the public, rather than encouraging a specific approach or behavior.
Patients and the public should be given clear information -- based on science rather than opinion or advocacy -- that explains cancer incidence and mortality, and provides transparent information about the risks and benefits of screening.
Furthermore, risks should be presented as absolute rates and in ways that can be easily understood, the researcher advised.
Another component of the new strategy would be the creation of a partnership among scientific and advocacy groups, but not to further develop and disseminate guidelines.
Rather, the task should be to develop the clearest educational materials so patients and caregivers can together make the most appropriate individual decisions on screening.
This informed decision-making approach should be accompanied by the implementation of measures that evaluate the number of patients who have been educated, rather than how many are screened.
In addition to these strategies, "and critically important, we need to energize work to identify markers that discriminate minimal-risk disease likely to have little impact on mortality versus high-risk disease," he wrote.
Shifting screening decisions away from a public health perspective to an informed individual approach will allow consideration of factors typically overlooked, such as anxiety about illness, acceptable degrees of risk, and the negative consequences of unnecessary treatment.
Such an approach, clearly informing patients about both benefits and harms of screening "involves a fundamental respect for individuals and a tolerance for truly informed decisions even if, as individuals ourselves, we would not make the same choice," Stefanek concluded.


The study was not supported by any research funding.
The author had no potential conflicts of interest.





Primary source: Journal of the National Cancer Institute

[AlaskaAngel]

Thanks for the post. DebL posted another in the articles forum recently that made similar points.

I also believe that in the patient's best interests, they should be told in advance what the financial cost is to those who have no insurance for such procedures, even if there are sources that can provide help, so that everyone knows right up front what those procedures can cost.

It would be interesting to know the same kind of statistics as applied to having annual breast cancer markers done instead, since there is no radiation involved, just a blood draw and analysis, which would be less expensive.

Abnormal markers don't always mean cancer, but they could be offered as an alternative by individual choice and could be followed up with a combination mammogram and ultrasound if they were abnormal. I wonder if they might actually do a better job of detection. Especially for those who are going without mammograms and ultrasounds in places where they are not covered.

A.A.

This may by why blood tests are not used, false positives occur with blood tests too.

From Susn Love:

Metastatic Disease
What is the CA 27.29 blood test? Should I have it done?

The FDA approved the CA 27.29 blood test in June 1996. It is the first and only blood test that is specific to breast cancer. (The two other blood tests that oncologists may recommend for women with breast cancer, the CA 15-3 and the CEA, are tumor marker tests that are used in breast and other cancers.) The CA 27.29 test measures the level of CA 27.29 antigen, which is found in the blood of breast cancer patients. As breast cancer progresses, the level of CA 27.29 antigen in the blood rises. In theory, by monitoring CA 27.29 test results oncologists can determine if the cancer has spread to other parts of the body, which is called metastasis. [Important point: If breast cancer metastasizes to the liver, it does not mean you have liver cancer. It means you have breast cancer cells in your liver, and the treatment used would be treatment for breast cancer, not treatment for liver cancer.]

Unfortunately, the CA 27.29 test is not as reliable as we initially hoped it would be. In statistical terms, it is neither "specific" nor "sensitive" enough to accurately determine if metastasis has occurred. What does that mean?

If a test for metastasis is highly sensitive, it will be good at finding those women who have metastasis and it will produce very few false negatives (women who are told they have negative results when they really don't). A test needs to be highly sensitive to rule out disease. In other words, when a test is highly sensitive, if a woman tests negative it means she does not have metastasis.

If a test for metastasis is highly specific, it will be good at finding those women who do not have metastasis and it will produce very few false positives (women who are told they have metastasis when they really don't). In other words, when a test is highly specific, if a woman tests positive it means that metastasis is indeed present.

Since it is not highly sensitive or specific, the CA 27.29 test can go up for reasons other than metastasis, resulting in false positives, and it may not go up when there is metastasis, resulting in false negatives. The CA 27.29 test has been proven to be helpful in following increases in metastasis in women who have already been found to have metastatic disease, allowing doctors to better adjust treatment regimens.

In addition to having the CA 27.29 test, your oncologist may recommend that you have the CEA and CA 15-3 tumor marker tests done as well. Neither of these tests is highly sensitive or highly specific either. If you choose to have any of these tests done it should be with the knowledge that there is currently no test or scan that can reliably tell us whether a small number of breast cancer cells have gotten into, and have begun growing in, other parts of the body, and that the information you receive may not be accurate.

Should you have the CA 27.29 test done? The American Society of Clinical Oncology recommends against routine testing of markers after a breast cancer diagnosis. Some oncologists recommend that women have this test every three to six months with the hope that they will find metastasis early. The problem is that there is no evidence that finding metastases by a blood test before a woman has symptoms will improve her survival or quality of life. The treatment of metastatic disease is aimed at reducing symptoms and putting the woman into remission. It is hard to improve symptoms if a woman does not have any. Most women whose breast cancer has metastasized do not show any symptoms until the disease is quite extensive. Symptoms of metastatic disease include bone pain, shortness of breath, lack of appetite and weight loss, and neurological symptoms like pain or weakness or headaches.

There are a series of tests that can help find large amounts of cancer cells in other parts of the body. These are called staging tests (this is not the same as the stages of breast cancer), and include chest X-rays, which can find cancer in the lungs, blood tests that can determine if the cancer has spread to the liver, and bone scans, which can help ascertain if the cancer has spread to the bone. CT scans are also used to detect the spread of cancer to the liver, the lungs, a certain area of bone, or even your brain. Like the blood tests, though, these tests are not good at finding small numbers of cancer cells.

Ultimately, the only way to determine whether having routine CA 27.29 testing is right for you is to think about how you want to handle the aftermath of your breast cancer treatment and whether a test that has limitations will be helpful for you. Some women find reassurance in having the CA 27.29 test done; others find the thought of having the test stressful and choose to not have it done. There is no "right" choice. If you do decide to have the test done, here are a few things you should know:

-a normal CA 27.29 level is usually less than 38 to 40 U/ml (units/milliliter),depending on where the lab test is done

-because anything under 40 is considered normal, you shouldn't worry if it's 20 one time and then 30 another time

-just because the test result is higher than 40 it doesn't mean your cancer has spread.

-Endometriosis, ovarian cysts, first-trimester pregnancy, benign breast disease, and kidney and liver disease are just some of the noncancerous conditions that can raise your CA 27.29 level.

[AlaskaAngel]

Yes. But that discussion primarily refers to the application of the blood testing for metastasis, which can't be compared to mammography because mammography doesn't detect metastasis.

The question is, would offering non-metastatic women the choice of having either 1) annual radiation exposure by mammography, with its false-positive and false-negative rate, or 2) annual breast cancer marker blood testing, with its false-positive and false-negative rate, (with follow up mammography and ultrasound for positive marker results, for further analysis) end up producing more helpful results and far less use of radiation?

Given that breast cancer marker blood testing is far, far less expensive (even with follow up mammography and ultrasound for those who have positive blood testing results), it might even be possible to offer twice-a-year blood testing, which could be superior to annual mammography.

A.A.

[Mtngrl]

AA--

Thanks for your thoughts. It's worth pondering.

Mammogram continues to be the "gold standard" in breast cancer detection, even though I keep seeing studies that show no overall survival benefit. That suggests the need for a new approach.

[AlaskaAngel]

The other plus involved for using the blood testing over the mammogram is that IT does offer some ability to detect metastasis, whereas the mammogram is only an indicator for recurrence in the breasts.

If repeated blood testing comes back abnormal, then one's provider could choose to do a combination mammogram/ultrasound, followed by MRI or bone scan or PET scan if necessary, and it might provide much earlier detection of mets than currently is available.

So, it depends on what the comparison value is for the actual success/failure rate for detection for the whole body is based on the blood testing vs what the comparison value is for the actual success/failure rate for detection for recurrence in the breasts alone.

I've never seen any reports for that comparison, but would like to.

My PCP has done the markers every year for me in addition to a mammogram.

A.A.