There’s big buzz about the hot prospects for blood tests designed to detect multiple kinds of cancer. President Biden highlighted them in a speech about the Cancer Moonshot program on Sept. 12, just a day after study results touted an experimental test’s ability to detect dozens of kinds of cancer. Meanwhile, the federal government is heralding an upcoming trial that will eventually enroll as many as 225,000 subjects.
There are plenty of reasons to be cautious, however. And if these tests become standard, the oncology field will need to figure out how to navigate a thicket of new challenges.
“Our friends in internal medicine and primary care will be looking to us for guidance. We need to make sure that we’re coming at this without too much optimism before we really have the data,” said Jyoti D. Patel, MD, medical director of thoracic oncology and assistant director for clinical research at the Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago.
Dr. Patel is a member of the communications workgroup of the Multicancer Early Detection Consortium, a nonprofit, public-private organization that’s providing insight and guidance into the development of screening tests. The consortium published a position paper earlier this year.
According to Dr. Patel, early cancer screening today can detect only five types of cancer: prostate, breast, lung, cervical, and colon. The Cancer Moonshot program has prioritized research into greatly expanding this number. President Biden referred to this goal in his Sept. 12 speech: “Imagine a simple blood test during an annual physical that could detect cancer early, where the chances of a cure are best.”
Biden said the National Cancer Institute is launching a major trial as part of the Cancer Moonshot program. The Vanguard Study on Multi-Cancer Detection plans to enlist 25,000 healthy women and men between 45 and 70 years old in 2024, then later enroll as many as 225,000 people.
Meanwhile, researchers reported on Sept. 11 that the Galleri multicancer detection blood test found positive cancer signals in 1.4% of 6,621 healthy subjects, and cancer was ultimately confirmed in 38% of those in that group. Nineteen solid tumors and 17 hematologic cancers were diagnosed; 26 of these were cancer types that don’t have routine screening available.
The Galleri test is widely available in the United States, although the $950 cost is not covered by insurance.
While the data is exciting, the high false-positive rate is worrisome, Dr. Patel said. “Are there ways that we can further define that by cancer-risk assessment or by having better captures in our technology that reflect RNA methylation or epigenetic changes that may lead to susceptibility to cancers?”
Additional research is essential
Ernest Hawk, MD, vice president and division head of cancer prevention and population sciences at the University of Texas MD Anderson Cancer Center, Houston, said it’s “absolutely essential” that research into screening tests clearly demonstrates improved patient outcomes over time.
“We need to have much longer follow-up of all participants – whether the screening results are positive or negative – and mitigate the potential risks of such testing,” said Dr. Hawk, who’s worked with the Multicancer Early Detection Consortium.
On another front, Northwestern University’s Dr. Patel highlighted that while easy-to-access cancer screening could create tremendous opportunities to treat early cancer and shrink disparities in care, it may produce “an onslaught of patients with early-stage disease. Do we have the workforce to help us?” Also, she said, “if we find a patient with early-stage disease, how are we going to risk-stratify their follow-up and adjuvant therapy? Are there ways to prognosticate with more granularity than we do now?”
What’s next? “Multicancer early-detection tests could truly revolutionize cancer care if they work as we hope they will, but only time, extensive participation in research, and hard work will prove whether that is true or not,” said MD Anderson’s Dr. Hawk. “I anticipate that we’ll have reasonable answers within the next decade, given the pace of existing company-sponsored research and NCI’s planned involvement in testing various technologies available.”
For her part, Dr. Patel said oncologists should be aware that multicancer screening tests are available and be ready to address questions about them. “Think about how you can advise patients in the absence of data,” she said.
Dr. Patel and Dr. Hawk have no relevant disclosures.