The information used in diagnosing a brain tumor takes many forms. At Dana-Farber/Brigham and Women’s Cancer Center (DF/BWCC), a patient’s brain tumor tissue undergoes a broad range of diagnostic tests: not only standard pathology exams in which tumor cells are viewed under a microscope, but also next-generation scans looking for mutated genes and misassembled chromosomes, as well as whole-genome searches for extra or missing copies of genes.
Such extensive testing helps pinpoint the exact type and characteristics of a particular tumor. The more specific the diagnosis, the more precise the therapy can be.
But test results are only as valuable as the ability of pathologists and physicians to interpret them. As the diagnosis of brain tumors becomes more complex, DF/BWCC pathologists and cytogeneticists (specialists who focus on chromosome structure) routinely consult one another, compare notes, and present physicians with a unified report on their diagnostic findings.
Keith Ligon, MD, PhD, along with his colleague Azra Ligon, PhD, both of the Center for Molecular Oncologic Pathology (CMOP) at DF/BWCC, have established a brain tumor diagnostic board, which draws specialists from across the various disciplines within pathology. At the meetings, attendees review individual brain tumor cases, presenting the results of the diagnostic tests within their specific area.
“The diagnosis of brain tumors today involves multiple streams of information from different tests,” says Dr. Ligon, who is a principal investigator in the CMOP. “By bringing as much information as possible to bear on each patient’s case, we can ‘tighten’ the diagnosis – narrow it down as precisely as possible – reduce the chance of misdiagnosis, give really useful prognostic information, and help oncologists arrive at an effective treatment.”
Tumor tissue from brain cancer patients at DF/BWCC undergoes at least four categories of cellular and molecular tests.
- Histopathology – a test in which the tissue is examined under a microscope for structural abnormalities.
- Immunohistochemistry – a test that focuses on cell proteins, called antigens, that signal a specific type of cancer.
- OncoCopy – a whole-genome scan that can detect extra or missing copies of certain genes.
- OncoPanel – examines the protein-coding portions of genes to identify mutations associated with cancer. (OncoPanel is part of the Profile program, directed by Neal Lindeman, MD, which analyzes tumor tissue for known cancer-related mutations.)
All exams are ordered within two weeks of the tissue becoming available, with the hope that results will be available in four weeks. In some cases, this multi-test, collaborative approach has enabled DF/BWCC pathologists to change a diagnosis that had been made incorrectly at another institution, Dr. Ligon says.
This post originally appeared on Insight, the blog of Dana-Farber Cancer Institute.