The 2000-gene-expression profiling (GEP) test may be a more cost-effective option than current strategies for identifying tumor origin in patients with cancer of unknown primary (CUP), a recent study suggests.
Knowing the region from which metastatic cancer originates can be an important factor for guiding treatment decisions and improving patient outcomes. Many guidelines and tests for CUP exist, but most modern methods only have success rates of between 20% and 25%. In 2012, the 2000-GEP test was approved for use in the United States by the Food and Drug Administration based on an 89.3% accuracy at identifying tumors’ primary site. However, while the test has been validated as a diagnostic tool, its health and economic outcomes have not been determined.
In a study published in Nature, researchers led by Malek Bassam Hannouf, Western University (Ontario, Canada), evaluated the incremental cost-effectiveness ratio (ICER) of using the 2000-GEP test to identify a primary tumor after clinical and pathological diagnostic evaluations had failed.
Researchers used statistical models and simulations to analyze the effect of 2000-GEP test use on patients’ life years (LYs), quality-adjusted life years (QALYs), and costs. A total of 1080 metastatic patients were diagnosed with CUP at a clinical practice in Manitoba, Canada, from January 2002 through December 2011. A model developed by the researchers predicted outcomes of 1.13 LYs and 0.63 QALYs for these patients. In contrast, with use of the 2000-GEP test, the model predicted outcomes would improve to 1.42 LYs and 0.87 QALYs.
Costs with and without 2000-GEP testing were CaD$28,609 and CaD$17,802, respectively. Results showed that the 2000-GEP-based strategy was preferred in 78.2% and 99.6% of simulations when using a willingness to pay threshold of $50,000 and $100,000 per QALY gained, respectively.
Overall, researchers determined that the ICER associated with use of the 2000-GEP test was $37,774 per LY gained and $44,151 per QALY gained, both of which are below ICER estimates for other current care strategies.
Researchers concluded that the 2000-GEP test provides value for patients with CUP when clinical and pathological diagnostic evaluations were unable to determine the site of tumor origin.
