Friday, November 20, 2009

Each woman is an individual and her breast care is her business

The federal Preventive Service recommendations on mammograms is not about rationing health care, although it does involve economic considerations.

Repeat, the "fewer mammograms" suggestion is not about parsing care, it relates to breast cancer as a public health issue, not a personal one.

Here it is in a nutshell: Do the anxiety, biopsies, surgeries, and expenses of mammograms justify their current use by women, not at any special risk, starting at age 40.

Studies show that one case of breast cancer is discovered by mammogram per 1,904 women tested. The problem is that the other 1,903 women may receive false positive results, meaning that they then undergo a biopsy, and possible surgery.

complications in biopsy and surgery are rare, but not unknown. Depending on the skill of the doctor "reading" the mammogram, the x-ray may show benign lesions, cysts, or "artifacts" such as shadows that aren't really there.

Suppose there were an extremely rare fatal disease curable if caught before the age of 5. Say this disease struck 1 person in 1 million. Even if the test were cheap, easy and accurate, a million people would need to take and pay for the test to reveal that single case, on average.

Clearly, for the diseased individuals, these kinds of screening tests can be lifesaving. But what if your doctor recommended the test, even though the chances of it occurring in your child were minuscule?

You might ask your pediatrician if it made sense to test everyone, because the risk is only 1 in 1 million, getting time off from work is a hassle, a doctor bill is a hassle, and putting a toddler through a medical test is emotionally and physically draining.

On the other hand, diseases like measles, mumps and rubella were so common and the vaccines so inexpensive and effective that virtually all children in the U.S. receive them before they are allowed to attend school.

Currently, about 1 in 8 women will develop breast cancer in her lifetime. Breast cancer is not a single disease; there are aggressive, invasive types, and slow growing types. Women with certain genetic mutations are more likely to develop breast cancer.

So undergoing mammograms at age 40 seems reasonable.

The five-year survival rate for breast cancer in women in the U.S. is about 89 percent, which is encouraging.

Here's what puzzles and confounds many men and women. Canadians followed 40,000 women ages 50 to 59 in the 13-year study that concluded in 2000. The women were split into one group who received physical exams and another that were given mammograms.

The Canadians found that though more cancers were detected by mammograms, their death rates were no lower than the physical exam group. The inescapable conclusion is that yearly mammograms did not increase survival rates after cancers were detected.

Can this be true? It makes little sense. The methodology of the test was criticized, including the quality of the mammograms. The age of the participants is another issue. All of the women probably faced an elevated risk, skewing the results.

This is why it is so important to read and understand medical reports and journal articles. Why it is important to study biology and physiology. You don't need to agree with evolution to be a good doctor, though genetics is part of an educated person's knowledge.

Even if the study had been conducted perfectly, epidemiology has to do with large numbers of people. Medicine pertains to the individual.

So when all is said and done, here's what you should do: Consult your own doctor or doctors about whether they think you should get or delay mammograms. Because you're the person at risk for breast cancer.

This is your life, and you should not allow an obscure public health meta-study to dictate what medical tests you choose, and when you choose them.

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