Les Jones

Science > 2005 Nobel Prize in Medicine, and Thomas's Three Phases of Medicine

Congratulations to Australians Barry J. Marshall and J. Robin Warren, winners of the 2005 Nobel Prize in Medicine for their discovery of the role of the bacterium Heliobacter pylori in gastritis and peptic ulcers.

Yesterday I talked about the different levels of scientific certainty in empiricial research. Today I want to talk about the different levels of certainty in medical knowledge, using ulcers as the model. In one of the essays in Lives of a Cell, Lewis Thomas describes three phases of medical understanding.

In the first phase of medical knowledge, there is no real understanding of the disease, and no meaningful treatment. In this phase, you might as well go to a witch doctor as an internist, because neither one can cure you. Fortunately, we've mostly progressed beyond this point today, so that doctors can do something for most diseases, but even in the 21st century some diseases are a death sentence.

In the second phase, there's some understanding, but the explanations are contradictory. For instance, we're not sure how genes and the environment interact in the development of cancer. In the case of ulcers, the proximal cause included everything from acidic foods to greasy foods to spicy foods, to smoking and drinking, but also to psychosomatic causes like stress. The cures may be multiple, painful, and expensive. Think of the way we treat cancer with a mix of surgery, radiation, and nausea-inducing chemicals.

In the third phase, we understand the pathology and know how to treat it. With the discovery that H. pylori causes peptic ulcers diagnosis can often be done by non-invasive breath testing: the patient breathes into a sample tube that captures samples of the bacteria. Treatment is simple, inexpensive, and painless - the sample tube determines which antibiotics to prescribe to treat the ulcer sufferer's strain of H. pylori. Medicine at this phase is at the level of magic.

In short, science and medicine are not uniformly advanced, and don't march forward in perfect lockstep. Some parts of science and technology are more mature than others, and we're fated to perpetually ask some version of the question, "If we can put a man on the moon, why can't we cure this child's disease?"