Cancer Screening

Living Well in Myanmar

No test may be the best

In attempting to access the best possible medical care for their families, patients often assume that getting a variety of medical tests will allow them avoid disease and live longer. For the slowly growing middle class of Myanmar and the expatriates who have chosen to live here, there is a perception that getting checked for many different types of cancers will help avoid the negative outcomes associated with those cancers.

Readers of Living Well in Myanmar will know that this is not always the case. Just because a screening test indicates you might have cancer doesn’t necessarily mean you actually have it. Even more difficult to understand is that even if you have a cancer, it may never cause a problem.

thyroid cancer

A great example comes from new research out of South Korea. In the late 1990s the South Korean government started a national cancer screening program hoping to improve the health of their population for diseases such as breast, cervical, colon, and stomach cancers. In addition, many doctors and hospitals included thyroid cancer screening by selling patients an ultrasound examination of the neck. The result has been a fifteenfold increase in thyroid cancer amongst the South Korean population, making it the most common cancer in the nation.

One might expect that finding all of this previously undiagnosed disease is improving health in South Korea by reducing the number of people who die from thyroid cancer. Unfortunately the death rate from thyroid cancer has remained unchanged -- and it was low to begin with anyhow. This means that all of these new cancers that were found and treated didn’t actually save people’s lives.

The South Korean experience is a stark example of overdiagnosis, finding disease that would be better left undiscovered because its treatment is unlikely to benefit the patient. The implication for patients and the health care system is not only excessive worry and cost, but also unnecessary harm in that cancer-removal surgeries can damage vocal chords. Furthermore most patients have to take thyroid replacement therapy for the rest of their lives after the thyroid gland has been removed.

Interestingly, some of the most meaningful advances in preventative health care have been learning to stop or alter how we use cancer screening tests. A prominent example is the PSA test for prostate cancer, which many medical societies now advocate avoiding altogether. In addition the guidelines on cervical and breast cancer screenings seem to continuously advocate reducing the scope and frequency of who gets tested and when.

We keep learning that many cancers are best left undiscovered. About a third of people who die of other causes are found on autopsy to have thyroid cancer that never bothered them in their lifetime. A similarly high percentage of men are found to have had prostate cancer that never affected them. Identifying these cancers while people were alive wouldn't have improved either the length or quality of their lives.

Nevertheless once screening tests do happen and patients are told they have cancers it becomes difficult to discuss delaying or avoiding treatment. A combination of fears surrounding cancer and the desire by doctors to do the procedures for which they are trained tends to push patient-doctor decision making towards pursuing an intervention.  Therefore national public health departments are obligated to encourage responsible screening practices by government and private medical systems.

Many laboratory and imaging tests that are known to cause more harm than good are currently sold in Myanmar and our neighboring countries. The process of engineering responsibility and accountability into our health care system will be difficult because of both the profit motive for medical professionals and the desire of people to access the ‘best medical care available’. In the meantime the best hope is a well-educated patient  © Christoph Gelsdorf 2013