Cancers are diverse, and that makes them extremely difficult to treat.
What worked for a tumor in the brain probably won’t work on a cancer of the liver.
Scientists are trying to outwit tumors by coming up with tailored treatments like the immunotherapy drug used to successfully treat former President .
A paper published Friday in Nature Communications suggests one thing that might help is identifying the astonishing mix of cells inside a tumor.
Tumors can swallow up cells around them and grow into composites of malignant and healthy tissue.
As that happens, they seem to take on different properties that could make them more or less responsive to an immunotherapy drug like Pembrolizumab, the medication that Carter received, one that works by stimulating the immune system to attack tumors, researchers say.
A lot of that has to do with the kinds of cells the tumor has taken up as it grows.
“Cancers actually have a lot of different types of cells in them, including immune cells or inflammatory cells that contribute to the impurity of the cancer in terms of pure cancer cells,” says Dr. Atul Butte, the director for the Institute for Computational Health Sciences at the University of California, San Francisco,who authored the study in Nature Communications on treating cancer with immunotherapy drugs.
By analyzing a database of tens of thousands of cancer patients in an open-access tool called the Cancer Genome Atlas, Butte and his colleagues saw that the composition of a tumor correlated with the success of treatment.
“The purity of their cancer actually had a lot to do with whether or not that patient ended up surviving that cancer and whether a particular drug seemed to be effective or not,” Butte says.
One of the most important types of cells embedded in tumors is immune cells, according to Dr. Reena Thomas, a neuro-oncologist at Stanford Health Care who was not involved in the study.
That might make immunotherapy drugs more potent, since immune cells have already infiltrated the tumor itself or are concentrated nearby.
If a tumor spreads to a different part of the body, like the lungs or the liver, the immune properties of that tumor might change.
The study found that some tumors carried an immune therapy gene signature that other tumors didn’t, Thomas says.
“If we can harness a particular chemotherapy plan to be specific to a tumor type and genetic signature, that the best thing we can do for them,” Thomas says.