2R-bitrary.

When it comes to finding an optimal treatment regimen for gastric cancer, we’ve had to go back to the drawing board a few times. There have been some late nights and forced votes, but recent targeted therapy trials keep falling short. It may be that we're trying to throw a single strategy at what is really a heterogenous disease. Last week’s pub takes a different approach by turning efforts towards better understanding what we already know works. Using specimens from the UK MAGIC trial, the authors tested for polymorphisms that might confer a better (or worse) response to epirubicin/cisplatin/5FU (ECF) chemotherapy. People with 2R/2R polymorphisms in the thymidylate synthase (TS) gene had better survival with chemo than those with other polymorphisms. The 2R means they have two tandem repeats ahead of the TS gene and produce less TS than people with 3R (3 repeats) polymorphisms. In other words, they had less TS to be blocked by 5FU. This is no silver bullet, but it does represent a step forward in tailoring existing and future therapies to individual patients rather than arbitrarily treating all gastric cancers as one.