Is molecular AP testing in sync with guidelines?

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Anne Paxton

November 2014—Molecular testing, on a steep growth curve in anatomic pathology, is increasingly providing decisive guidance for treatment of cancer patients. But while guidelines on clinical relevance and performance of common molecular tests are available and widely used in theory, to date there has been limited information on how well requests for molecular testing in AP laboratories are adhering to the guidelines.

The CAP Quality Practices Committee hopes to fill part of that gap with its “Molecular Testing in Anatomic Pathology” Q-Probes study. The authors believe it is the first multi-institutional study assessing the effectiveness of anatomic pathology molecular testing by examining adherence to guidelines of the National Comprehensive Cancer Network, or NCCN.

“Recently there has been a significant upsurge in molecular testing. It seems like every time you turn around there is a new test,” says study coauthor Michael Idowu, MD, director of the molecular genetic pathology fellowship and anatomic pathology quality management at the Virginia Commonwealth University Health System. “Appropriate test utilization and test performance are important for usable test results. We decided on this study because of increasing use of molecular testing and its impact on therapy.”

A study of 26 laboratories and 2,230 test requests, this Q‑Probes looked at three criteria for evaluating molecular testing quality in AP: the appropriateness of requests for molecular testing, the adequacy of test material, and turnaround time.

Dr. Idowu

The authors considered two data collections: a prospective review of all cases for which molecular testing was requested, and a retrospective review of molecular testing performed or attempted in cases of lung carcinoma, colorectal carcinoma, and melanoma. “Tests where results determine whether a patient gets a targeted treatment or not were the focus of the study,” Dr. Idowu says.

The data show that strict compliance with NCCN guidelines is far from ideal. (Strict adherence means the test is in the NCCN guideline as an integral part of the decision-making algorithm.) For all case types, the study found, a median of 53 percent strictly met the guidelines in a prospective review, and for cases of lung and colorectal carcinomas and melanoma, 71 percent met the guidelines in a retrospective review. The prospective study also found that a median of 94 percent of all cases at least loosely met guidelines and, on retrospective review, 95 percent of lung, colorectal, and melanoma cases did so. (Loose adherence means the test is not part of the NCCN algorithm but is directly related to other standard tests in the guideline or mentioned in the guideline as a consideration in certain malignancies.)