A provocative new finding from U.K. researchers gives the push for personalized medicine a big black eye. They found that a single tumor can actually contain a number of genetic differences, and tumors can also differ drastically on a genetic level from each other. That means that the typical, single biopsy only paints one tiny part of a cancer's molecular picture.
This is potentially significant news, with details of the Cancer Research U.K. London Research Institute study published in The New England Journal of Medicine. News outlets including Reuters, Bloomberg, and the The Associated Press have picked up the story. Here's why this is a big deal: The finding, if it stands, could make the process of genetically profiling patients and their tumors, and then developing or matching a specialized treatment that addresses the mutation, more challenging than previously believed. Thus, personalized medicine for the masses becomes much harder to obtain.
"If you stick a needle in the right side of the tumor, you could miss a key mutation in the left side," study co-author Andrew Futreal explained to Bloomberg.
On the one hand, this is a huge indictment of existing approaches toward developing treatments from a single biopsy. And the researchers said guiding treatment based on genetic tumor markers, as has been the practice, probably doesn't cover enough bases. But Reuters says the finding--which comes from a genome-wide analysis of the genetic changes of different parts of the same tumor--also challenges the viability of treatments already developed to target cancers with specific genetic qualities. The NEJM speaks similarly, and argues in an editorial cited by The Associated Press that the results could point to why the 15-plus "personalized" medicines already on the market so far only have had limited benefit.
On the other hand, technology may be a few years away from fixing the problem. Brian Druker, a researcher who helped develop Gleevec, a gene-based leukemia drug sold by Novartis ($NVS), told Bloomberg that he expects advances in genetic sequencing, and its increased affordability, to solve the problem eventually. The reason? Cheaper genetic sequencing will allow doctors to affordably sequence many parts of a tumor, or multiple tumors from the same patient and then develop a detailed treatment plan as a result, said Druker, now director of the Knight Cancer Institute at the Oregon Health & Science University in Portland, OR. But many cancer patients, of course, don't have a few years.
- here's the Bloomberg story
- check out Reuters' take
- read The Associated Press coverage
- here's The Globe and Mail story
- consider the NEJM journal abstract
- link to the NEJM editorial (purchase required)