Finding Risks, Not Answers, in Gene Tests

It is a fundamental principle of rationality that having better information should not put you in a worse position.

The article quotes Dr. Kenneth Offit, the chief of clinical genetics at Memorial Sloan Kettering Cancer Center saying these tests "because they could be tested, not necessarily because they should be”. I think this is representative of the attitude of the larger medical community; they're used to performing tests in response to something, and if they find something, they follow a protocol dictating the steps to be performed in response. I've heard a similar argument against full-body scans, saying that if a lump is detected, it is likely benign, but it has to be investigated lest the doctor become subject to a malpractice suit in the future. This is the case even if the expected benefit of a biopsy is negative due to the low likelihood of malignancy and the side-effects of a biopsy.

Fundamentally, medicine needs to change. In principle, doctors should choose their course of action based on the expected outcome, incorporating all available information. In many cases this action will be to do nothing. As more information is gathered by the medical community as a whole about, for example, the causitive relation between certain genes and diseases, the underlying models dictating the appropriate action can be updated. Unfortunately, until doctors believe they can take no action if they think it best without being threatened by litigation, we're going to be subject to this problem.

We're at a slippery slope where we'll simply need more data points to better assess identification of medical predispositions based on gene analysis. Unfortunately, the negative externality that forms, and the one referenced when things like "should be" is said, pertains to patients' responses to this additional information. We don't even have enough data to full reflect on how patients are reacting to this information.

Right now, most medicine is reactionary-- confirming suspicions when patients are presenting x symptoms. These tests, however, hope to be predictive, and like many predictive aspects of life, will have associated confidence intervals. People, especially with regards to their own health, will have a hard time factoring in these odds when presented additional information.

Even assuming these tests were highly accurate indicators of cancer, some carriers might literally die before either they get cancer or suffer any ill effects from the cancer.

Our bodies do naturally fight a lot of cancerous growths, which is why a family with a gene which makes them more susceptible to XYZ might never suffer from XYZ. The cells might grow out of control, then get nuked by the immune system before they get too big.

I cannot decide if such generic tests are helpful or unhelpful. On one hand it might make people extra vigilant to a certain condition, but on the other hand do damage to their mental health as the stress of "maybe" coming down with something deadly any day.

Plus family history seems a like more reliable as an indicator.

Why on earth do these tests cost $4,000? You are just looking for a few snps, 23andme can do that for under $100. Presumably it's because of whose paying?