Cancer diagnosis has shifted from traditional tissue pathology to detailed molecular analysis, recognizing that cancer is fundamentally a disease of the genome driven by specific DNA alterations. An oncopanel is a sophisticated genetic testing tool that profiles these underlying characteristics. It provides the molecular blueprint of a cancer, moving the focus toward personalized treatment strategies.
What is an Oncopanel?
An oncopanel is a type of genetic test that uses Next-Generation Sequencing (NGS) technology to simultaneously analyze a large number of genes associated with cancer development and progression. Unlike earlier, single-gene tests that screened for one specific mutation, oncopanels examine dozens to hundreds of cancer-related genes at once. This multi-gene approach provides a comprehensive view of the tumor’s genetic profile from a single test.
These panels primarily detect acquired, or somatic, mutations, which are changes occurring only within the tumor cells and are not inherited. The oncopanel sequences DNA extracted from tumor tissue to look for various genetic alterations. These alterations include single-nucleotide variants (point mutations), small insertions or deletions (indels), copy number variations (CNVs), and gene fusions, where two separate genes abnormally join.
The technical process involves extracting the tumor DNA, preparing it for sequencing, and using machines to read the genetic code of the targeted genes. This simultaneous testing is more efficient and cost-effective than running multiple single-gene assays sequentially. While the primary focus is on somatic changes, some panels may also detect germline variants, which are inherited and present in all cells, potentially indicating an underlying hereditary cancer risk.
The Role of Oncopanels in Precision Oncology
Oncopanels are a tool in precision oncology, linking a tumor’s specific genetic alterations to targeted therapeutic options. This approach shifts treatment away from a “one-size-fits-all” model based only on the cancer’s location, such as lung or breast, to one based on its unique molecular drivers. The findings help determine which treatments are most likely to be effective against the patient’s individual cancer.
For example, a traditional diagnosis of lung cancer is refined by identifying a specific mutation, such as an EGFR mutation or an ALK gene fusion, that drives tumor growth. Once these molecular targets are identified, the oncologist selects a corresponding targeted therapy, often a small molecule inhibitor, designed to block the activity of that mutated protein. This precision can lead to better patient outcomes and fewer side effects than traditional chemotherapy.
Oncopanel results are frequently used to determine a patient’s eligibility for clinical trials, beyond selecting already approved therapies. Many trials are designed to test new drugs based on a particular molecular alteration, regardless of the tumor’s origin. By profiling the tumor, the test helps match the patient’s cancer to an investigational drug that directly addresses the underlying genetic mechanism. The results can also provide prognostic information, giving insight into how the cancer may behave over time.
Navigating the Testing Process
The first step in obtaining an oncopanel test is the collection of a biological sample, typically ordered by an oncologist or specialist. For solid tumors, the most common sample is formalin-fixed, paraffin-embedded (FFPE) tissue, which is residual material from a prior biopsy or surgical procedure. The quality of this sample is important, as the tissue must contain a minimum percentage of tumor cells for successful analysis.
In some cases, a liquid biopsy (a simple blood draw) may be used as an alternative or complement to tissue testing. This method detects tumor DNA shed into the bloodstream, offering a non-invasive way to profile the cancer. Once the sample is sent to a specialized laboratory, the turnaround time for the final report generally ranges from two to four weeks.
Patients should consider the administrative and financial aspects of the testing process. Insurance coverage for oncopanels can vary widely, and pre-authorization is often necessary before the test is performed. The ordering physician and their team typically navigate these logistical steps to ensure the patient receives the molecular information in a timely manner.
Interpreting Oncopanel Results
The oncopanel report organizes detected genetic changes into categories based on their clinical relevance to guide treatment decisions. The most straightforward findings are Actionable Findings, which represent alterations with a direct link to an approved targeted therapy or a specific clinical trial. These findings are often classified as Tier I, indicating strong clinical significance for the patient’s tumor type.
Next are Non-Actionable or Informational Findings, which describe mutations known to be cancer-related but lacking a matching approved drug or clear therapeutic guidance. These findings, sometimes classified as Tier II or Tier III, are valuable because they contribute to understanding the tumor’s biology and may become actionable as new drugs are developed.
A frequent and complex finding is the Variant of Unknown Significance (VUS), which represents a genetic change whose effect on the cancer is not yet known. VUS findings are common, occurring in nearly 20% of genetic tests, and cannot be interpreted as definitively harmful or harmless based on current scientific evidence. Clinicians generally do not base treatment decisions on a VUS, but these findings are monitored and may be reclassified as more data becomes available over time.
The full interpretation of the oncopanel results is best achieved through a multidisciplinary tumor board. Experts like molecular pathologists and oncologists collaboratively discuss the molecular profile and align it with the patient’s clinical picture.