In the case of many forms of cancer, including the skin cancer known as melanoma, tailored drugs can eradicate cancer cells in the lab, but often produce only partial, temporary responses in patients. One of the burning questions in the field of cancer research has been and remains: how does cancer evade drug treatment?

New research by a team from the Broad Institute, Dana-Farber Cancer Institute, and Massachusetts General Hospital suggests that some of the answers to this question do not lie in cancer cells themselves. To find the answers, scientists are looking beyond tumor cells, studying the interplay between cancer cells and their healthy counterparts. The research team has found that normal cells that reside within the tumor, part of the tumor microenvironment, may supply factors that help cancer cells grow and survive despite the presence of anti-cancer drugs. These findings appear online this week in a paper published in Nature.

"Historically, researchers would go to great lengths to pluck out tumor cells from a sample and discard the rest of the tissue," said senior author Todd Golub director of the Broad's Cancer Program and Charles A. Dana Investigator in Human Cancer Genetics at the Dana-Farber Cancer Institute. Golub is also a professor at Harvard Medical School and an investigator at Howard Hughes Medical Institute. "But what we're finding now is that those non-tumor cells that make up the microenvironment may be an important source of drug resistance."