Doctors in Boston are reporting an advancement in the treatment of lung cancer patients. 

It’s a blood test that can quickly show which treatments would work best for patients’ most advanced tumors. 

The test, called a liquid biopsy, offers doctors new insight into a person’s lung cancer. 

"A blood test: a non-invasive way of understanding what the lung cancer is thinking," Dr. Geoff Oxnard, Thoracic Oncologist at Dana-Farber Cancer Institute, said. 

Conventional lung tissue biopsies are invasive and can be risky, painful and take more than a month for results. 

The liquid biopsy tested at Dana-Farber has a three-day turnaround. 

"If we can get a quick result in a couple of days that tells us where to go next, instead of spending weeks trying to figure out how to get a biopsy and get those results, we can accelerate the ability to give effective targeted therapy to that patient," Oxnard said. 

When positive, doctors said the blood test is just as accurate as the tissue biopsy. 

If it does not pick up on the cancer mutations, a traditional lung biopsy must still be done. 

For now, the test is only used to help guide treatment for patients. 

A blood test to diagnose lung cancer is still years away. 

As far as cost, liquid biopsies can range from several hundred to several thousand dollars. 

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