A test called CancerSEEK made recent headlines based on its potential for detecting eight different types of cancer. CancerSEEK represents a new approach, testing blood for certain genes and proteins that could indicate the presence of disease. But current evidence does not support its broad use for cancer screening.
More information is needed to determine whether the test would have a life-saving impact.
In response to current findings, the Society of Gynecologic Oncology of Canada (GOC) says CancerSEEK is “interesting but not yet ready for prime time as a test for detecting ovarian cancer.”
CancerSEEK found ovarian cancer when the disease was widespread. However, for CancerSEEK to serve as an effective screening method, it would have to accurately detect early stage ovarian cancer so that treatment can occur when tumours are small. In these cases, the test’s overall detection rate dropped below 50% on average, this result combined information for every type of cancer in the study.
“The important questions to be answered are: can CancerSEEK detect ovarian cancer when it is still localized – particularly for cases of high grade serous ovarian cancer, the most common subtype of this disease? More importantly, are we able to detect the cancer early enough to improve outcomes and save lives using the treatments we have available today, such as surgery and chemotherapy?” says Dr. Walter Gotlieb, President of GOC.
Ovarian cancer itself is not only one disease. It encompasses a variety of subtypes that respond differently to treatment. For instance, some can be treated successfully with surgery alone. The study did not provide a breakdown of ovarian cancer cases by subtype and without information on what exactly is being detected, it is unclear whether CancerSEEK would significantly improve outcomes.
Though it may be a useful research tool, CancerSEEK is not ready for wider use. By presenting a new approach that looks at genes and proteins in blood, the test does offer potential for effective screening, but this can only be realized following further study. It will take more time and research to refine CancerSEEK and pinpoint circumstances in which it may have an impact.