SNaPshot Makes Genetic Testing a Snap

Cancer patients screened for broad range of genetic mutations

(RxWiki News) In the not too distant future, sophisticated genetic screening may be done on a routine basis in a hospital lab. And this means cancer patients increasingly will be treated with therapies that target their specific genetic needs.

Researchers have demonstrated it's now possible to screen cancer patients for a number of different cancer-causing genetic changes. This can be done in a normal clinical practice, and results can be returned in a few weeks to help design individual, personalized treatment plans.

"If you have cancer, ask your oncologist about genetic screening."

The test is called SNaPshot. It was developed by a team of researchers led by Lecia Sequist, M.D., M.P.H., assistant professor of medicine at Harvard Medical School and thoracic medical oncologist at the Massachusetts General Hospital Cancer Center in Boston, and Dora Dias-Santagata, Ph.D., co-director of the Translational Research Laboratory in the Massachusetts General Hospital Pathology Department and Instructor of Pathology at Harvard Medical School.

SNaPshot tests more than 50 hot spots where mutations often occur in 14 major cancer genes, including - EGFR, KRAS, BRAF, HER2, among others.

Dias-Santagata explains that the test looks at genetic changes that happen in cancer cells, but not healthy cells in the body. These mutations disrupt the behavior of normal cells, enabling them to multiply out of control, a process that results in tumors.

Targeted therapies, also known as "smart drugs" are now available to attack and subdue genetic abnormalities in a various cancer types. SNaPshot helps to match patients with these therapies by identifying their individual genotypes, Dias-Santagata says.

And this personalized medicine can be life-changing for patients. Dr. Sequist says that the right therapy can improve response rates among non-small-cell lung cancer (NSCLC) patients from 20-30 percent to 60-75 percent.

To test this method, researchers used SNaPshot to analyze samples from 589 NSCLC patients from March 2009 to May 2010.

The technology identified genetic changes in 51 percent of the samples. A total of 353 patients had advanced disease, and 170 had genetic mutations or rearrangements which were classified as "potentially targetable."

Dr. Sequist says this "broad multiplexed genetic screening" is going to become common for lung cancer patients.

The researchers say SNaPshot can be performed in most molecular diagnostic labs, using existing equipment.

While the technique was first used with NSCLC patients, Dias-Santagata and colleagues have extended its applications and are now using it to screen other solid tumors such as colorectal, breast and gliomas.

Plans for the future call for using the technology to analyze cancers of the blood, including acute myeloid leukemia (AML).

This research is published in the November 8, 2011 issue of Annals of Oncology.

Review Date: 
November 8, 2011