What if you threw a personalized medicine party and lots of people got lost along the way? Apparently, that's what's happening with Roche's breast cancer drug Herceptin. According to a new study, two-thirds of patients don't get the genetic test that determines whether they will respond to Herceptin treatment. And even in those who get the test, one in five of the test results may be incorrect, the researchers found.
Herceptin is phenomenally successful--for a relatively small group of patients. It works for about 20 percent to 30 percent of women with invasive breast cancer, namely those who have extra copies of the HER2 gene. So in theory, screening patients for their HER2 status makes a lot of sense. Why give an expensive drug to a bunch of patients who won't benefit, but could suffer side effects? And why deny it to a woman whose life might be saved?
In practice? "Our review of the literature suggests that there are important knowledge gaps regarding the real-world use of HER2 testing" and Herceptin, said Elena Elkin, a researcher at Memorial Sloan-Kettering Cancer Center (as quoted by Bloomberg). In their article--published in the journal Cancer--researchers suggest that testing and documentation be standardized so that the women who need Herceptin are sure to get it.