Analyses presented during a session at the American Association for Cancer Research annual meeting, revealed that three new MCED tests — CanScan, MERCURY, and OncoSeek — could detect a range of cancers and recognize the tissue of origin with high accuracy. One — OncoSeek — could also provide an affordable cancer screening option for individuals living in lower-income countries.
The need for these noninvasive liquid biopsy tests that can accurately identify multiple cancer types with a single blood draw, especially cancers without routine screening strategies, is pressing. “We know that the current cancer standard of care screening will identify less than 50% of all cancers, while more than 50% of all cancer deaths occur in types of cancer with no recommended screening,” said co-moderator Marie E. Wood, MD, of the University of Colorado Anschutz Medical Campus, in Aurora, Colorado.
That being said, “the clinical utility of multicancer detection tests has not been established and we’re concerned about issues of overdiagnosis and overtreatment,” she noted.
The Early Data
One new MCED test called CanScan, developed by Geneseeq Technology, uses plasma cell-free DNA fragment patterns to detect cancer signals as well as identify the tissue of origin across 13 cancer types.
Overall, the CanScan test covers cancer types that contribute to two thirds of new cancer cases and 74% of morality globally, said presenter Shanshan Yang, of Geneseeq Research Institute, in Nanjing, China.
However, only five of these cancer types have screening recommendations issued by the US Preventive Services Task Force (USPSTF), Dr. Yang added.
The interim data comes from an ongoing large-scale prospective study evaluating the MCED test in a cohort of asymptomatic individuals between ages 45 and 75 years with an average risk for cancer and no cancer-related symptoms on enrollment.
Patients at baseline had their blood collected for the CanScan test and subsequently received annual routine physical exams once a year for 3 consecutive years, with an additional 2 years of follow-up.
The analysis included 3724 participants with analyzable samples at the data cutoff in September 2023. Among the 3724 participants, 29 had confirmed cancer diagnoses. Among these cases, 14 patients had their cancer confirmed through USPSTF recommended screening and 15 were detected through outside of standard USPSTF screening, such as a thyroid ultrasound, Dr. Yang explained.
Almost 90% of the cancers (26 of 29) were detected in the stage I or II, and eight (27.5%) were not one of the test’s 13 targeted cancer types.
The CanScan test had a sensitivity of 55.2%, identifying 16 of 29 of the patients with cancer, including 10 of 21 individuals with stage I (47.6%), and two of three with stage II (66.7%).
The test had a high specificity of 97.9%, meaning out of 100 people screened, only two had false negative findings.
Among the 15 patients who had their cancer detected outside of USPSTF screening recommendations, eight (53.3%) were found using a CanScan test, including patients with liver and endometrial cancers.
Compared with a positive predictive value of (PPV) of 1.6% with screening or physical exam methods alone, the CanScan test had a PPV of 17.4%, Dr. Yang reported.
“The MCED test holds significant potential for early cancer screening in asymptomatic populations,” Dr. Yang and colleagues concluded.
Another new MCED test called MERCURY, also developed by Geneseeq Technology and presented during the session, used a similar method to detect cancer signals and predict the tissue of origin across 13 cancer types.
The researchers initially validated the test using 3076 patients with cancer and 3477 healthy controls with a target specificity of 99%. In this group, researchers reported a sensitivity of 0.865 and a specificity of 0.989.
The team then performed an independent validation analysis with 1465 participants, 732 with cancer and 733 with no cancer, and confirmed a high sensitivity and specificity of 0.874 and 0.978, respectively. The sensitivity increased incrementally by cancer stage — 0.768 for stage I, 0.840 for stage II, 0.923 for stage III, and 0.971 for stage IV.
The test identified the tissue of origin with high accuracy, the researchers noted, but cautioned that the test needs “to be further validated in a prospective cohort study.”