Former Reason Editor Virginia Postrel (read her Reason archive) has a must-read two-part series up at Bloomberg View about how researchers are redefining "cancer."
Snippet from part one:
An enormous study published last month in the journal Nature analyzed samples from 825 breast-cancer tumors, using five different tests to find mutations in different aspects of their genetics. Researchers crunched the resulting data to classify the cancers into four general types: Luminal A, Luminal B, HER2-enriched, and basal-like. (They also identified a fifth type, dubbed normal-like, but didn't have enough samples to adequately study it.) Given its underlying genetics, each type might be susceptible to a specific treatment approach.
The study refines the way oncologists understand the different versions of the disease. The biggest news was that the basal-like cancers had more in common with the most common ovarian cancer, called serous, than with other types of breast cancer.
The second article underscores the implications for treatment:
When analyzed at the molecular level, a cancer that has traditionally been viewed as a single disease commonly fragments into many different subtypes, each possibly requiring a different treatment. There are now tests for about 200 different such abnormalities, which may occur by themselves or in combination.
"We should realize first that every patient is different," says Tsimberidou. "We cannot treat all patients with, say, colorectal cancer the same or think, for instance, that all metastatic liver disease is the same. In addition to the standard diagnostic procedures, we should perform a more refined tumor molecular analyses to better characterize every patient's disease, and we have to tailor the treatment to the specific tumor and patient characteristics."