Early data suggest that new multicancer early detection (MCED) tests in development show promise for identifying cancers that lack routine screening options.
Analyses presented during an April 7 session at the American Association for Cancer Research (AACR) annual meeting revealed that two new MCED tests — CanScan (Geneseeq Technology; Nanjing, China) and OncoSeek (SeekIn; Shenzen, China) — could detect a range of cancers and recognize the tissue of origin with high accuracy. 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.
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
CanScan 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 mortality globally, said presenter Shanshan Yang, of Geneseeq Technology in Nanjing, China.
However, only five of these cancer types have screening recommendations issued by the US Preventive Services Task Force (USPSTF), Yang added.
The interim data comes from an ongoing large-scale prospective study evaluating the MCED test in a cohort of asymptomatic individuals aged 45-75 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, Yang explained.
Almost 90% of the cancers (26 of 29) were detected at 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 disease (47.6%) and two of three with stage II disease (66.7%).
The test had a high specificity of 97.9%, meaning that 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 (PPV) of 1.6% with screening or physical exam methods alone, the CanScan test had a PPV of 17.4%, Yang reported.
"The MCED test holds significant potential for early cancer screening in asymptomatic populations," Yang and colleagues concluded.
MCED in Low-Income Settings
The session also featured findings on a new affordable MCED test, OncoSeek, which could provide greater access to cancer testing in low- and middle-income countries.
The OncoSeek algorithm identifies the presence of cancer using seven protein tumor markers alongside clinical information, such as gender and age. Like other tests, the test also predicts the possible tissue of origin.
The test can be run on clinical protein assay instruments that are already widely available, such as the Roche cobas analyzer, Mao Mao, MD, PhD, the founder and CEO of SeekIn, of Shenzhen, China, told Medscape Medical News.
This "feature makes the test accessible worldwide, even in low- and middle-income countries," he said. "These instruments are fully automated and part of today's clinical practice. Therefore, the test does not require additional infrastructure building and lab personal training."
Another notable advantage: The OncoSeek test only costs about $20, compared with other MCED tests, which can cost anywhere from $200 to $1000.
To validate the technology in a large, diverse cohort, Mao and colleagues enrolled approximately 10,000 participants, including 2003 cancer cases and 7888 noncancer cases.
Peripheral blood was collected from each participant and analyzed using a panel of seven protein tumor markers: AFP, CA125, CA15-3, CA19-9, CA72-4, CEA, and CYFRA 21-1.
To reduce the risk for false-positive findings, the team designed the OncoSeek algorithm to achieve a specificity of 93%. Mao and colleagues found a sensitivity of 51.7%, resulting in an overall accuracy of 84.6%.
The test's performance was consistent in additional validation cohorts in Brazil, China, and the US, with sensitivities ranging from 39.0% to 77.6% for detecting nine common cancer types, including breast, colorectal, liver, lung, lymphoma, esophagus, ovary, pancreas, and stomach. At 77.6%, it sensitivity for pancreatic cancer was at the high end. The test could determine the tissue of origin in about two thirds of cases.
Given its low cost, OncoSeek represents an affordable and accessible option for cancer screening, the authors concluded.
Overall, "I think MCEDs have the potential to enhance cancer screening," Wood told Medscape Medical News.
Still, questions remain about the optimal use of these tests, such as whether they are best for average-risk or higher-risk populations, and how to integrate them into standard screening, she said.
Wood also cautioned that the studies presented in the session represent early data, and it is likely that the numbers, such as sensitivity and specificity, will change with further prospective analyses.
And ultimately, these tests should complement, not replace, standard screening. "A negative testing should not be taken as a sign to avoid standard screening," Wood said.
Yang is an employee of Geneseeq Technology Inc. Mao is an employee of SeekIn. Wood had no disclosures to report.