The 86 cancer patients were a disparate group, with tumors of the pancreas, prostate, uterus or bone. One woman had a cancer so rare there were no tested treatments. She was told to get her affairs in order.
All the patients carried genetic mutations that disrupted the ability of cells to fix damaged DNA. And all were enrolled in a trial of a drug that helps the immune system attack tumors.
The results, published on Thursday in the journal Science, are so striking that the Food and Drug Administration already has approved the drug,
Just 4 percent of cancer patients have the type of genetic aberration susceptible to pembrolizumab. But that adds up to a lot of patients: as many as 60,000 each year in the United States alone, the study's investigators estimated.