Sparing Patients: Attacking Drug-Resistant Cancer in a Dish

When a cancer patient’s first line of treatment stops working, doctors often need to race the clock to find another regimen to keep the disease at bay. In recent years they’ve turned to genetic tests, which can help them find the cancer’s weak spots so they so they can fight it more effectively.

Unfortunately, this testing doesn’t always give doctors the answers they’re looking for. But soon doctors may have a second option. Researchers have found a new drug screening method that may one day keep doctors from having to resort to trial and error when choosing a new therapy.

Researchers at the Massachusetts General Hospital Cancer Center recently learned how to grow a patient’s cancer cells in a laboratory so they can test them against different drugs to see which ones will be the most effective. Today researchers are looking to refine this process so it can one day be used by doctors to spare their patients fruitless treatments and wasted time.

The Problem of Drug Resistance

One of the biggest hurdles doctors face when it comes to killing off cancer cells is that these cells are smart and they can adapt. This means that often within a year or two, a therapy that was holding a cancer at bay stops working, allowing the cancer to resume and forcing doctors to find replacement treatments.

Researchers looking to solve this resistance problem knew that while genetic testing can offer clues when it comes to some types of cancer, it doesn’t always identify new treatments that will be effective. So they decided to find an alternative. They devised a way to directly test different drugs against these resistant cancers, without having to test mediations on actual patients.

In order to do this, they had to harvest treatment-resistant lung cancer cells from patients and grow them outside the body. Once they were able to do that they then tested 76 different drugs on those lung cancer cells to see which medicines worked the best. Some of the drugs they used in tests were already FDA-approved, others were experimental. They tried the drugs both by themselves and combined with the original treatment that the cells had become resistant to.

Using this method, researchers found drug combinations that worked against some of the cancers-in 45 of 55 groups of cancer cells tested, adding a second drug was able to make the first drug work again.

In addition to finding combinations of drugs that worked, researchers also gained new insights about how certain types of cancers develop drug resistance in the first place, which may help them improve treatments in the future. Some of the resistance pathways they discovered wouldn’t have been found if scientists just used genetic testing alone.

The hope is now that the research team will be able to develop biopsy and testing procedures that will allow tumor samples to be tested quickly, within a few weeks after a patient’s biopsy, which will arm doctors with new information about how to best fight a patient’s cancer.

“This screening was so effective that we think it warrants a serious effort to develop the technology for personalized treatment decision making,” says Jeffrey Engelman, MD, PhD, co-senior author of a paper covering the research  which appeared in Science and on the Science Express website.