Jan 18, 2018

Early testing of new blood cancer screening shows some promise

A robot processes samples for evaluation from the blood-based CancerSEEK test. Photo: Fred Dubs / Johns Hopkins Medical Pathology

Scientists announced Thursday in the journal Science that they've developed a highly specific blood test that screens for 8 common cancer types, helps identify the location of the cancer, and is expected to cost about $500.

Why it matters: The research community is searching for a non-invasive way to screen for cancer but has faced huge problems of high costs and false positives — which can cause a patient unnecessary testing and anxiety.

Yes, but: The study was conducted in a relatively small number of cancer patients. Some scientists believe the high specificity and sensitivity rates of the CancerSEEK test may drop in a larger patient group and say they will be watching the results from a larger trial expected in about 18 months.

"The key is to find [cancer tumors] early," says study author Nickolas Papadopoulos of the Johns Hopkins Kimmel Cancer Center. "Then the [treatment] therapeutics will work better, the surgeries will work better."

The study details: Over several years, the team tested 1,005 cancer patients (with stage I to III cancers that had not metastasized) and 812 healthy people to assess mutations in cancer genes and circulating proteins that tend to indicate cancer.

  • They focused on segments of 16 cancer genes and 8 protein biomarkers in an effort to increase the sensitivity and specificity and lower the cost of sequencing.
  • They then developed an algorithm that analyzes specific protein and genetic mutations to help narrow down the body location of the cancers.
  • Of the 8 cancers (ovary, liver, stomach, pancreas, esophagus, colorectum, lung and breast) in the test, 5 of them do not yet have any screening test. These cancers account for roughly 60% of all cancer deaths in the U.S.

What they found: The team detected cancer with a sensitivity of 69%–98%, depending on the cancer, and showed a 99% specificity meaning there were few false positives.

  • Less than 1%, (or 7 out of 812) of the healthy controls had a false positive.
  • The algorithm was able to locate the source of the cancer to two sites in the body in 83% of these patients, and to a single organ in 63% of the patients.

Study limitations: Theodora Ross, director of UT Southwestern Medical Center’s Cancer Genetics Program who was not part of this study, says the paper has "an intriguing idea to combine distinct [protein and ctDNA] assays to increase sensitivity without losing specificity” but the patient cohort presents limitations.

Ross says the patients should not include Stage III cancer patients, particularly for ovarian cancer patients who often have protein biomarkers that are easier to detect and can skew the sensitivity results of blood tests.

A big challenge: H. Gilbert Welch, a professor at The Dartmouth Institute who also was not part of the study, says one of the real challenges of blood biopsies, is that once you get a false positive, doctors do not know when to stop looking for the elusive cancer.

"How do we put it to bed that we don't have cancer, once people have a positive [but false] liquid biopsy," Welch says.

What's next: Papadopoulos says they have started Phase A trial of 10,000 patients. This is part of a $50 million, 5-year study of up to 50,000 women being funded by philanthropic group The Marcus Foundation, Science magazine reports.

Go deeper

Cuomo says New York is "literally going day-to-day with our supplies"

New York Gov. Andrew Cuomo said in a press conference on Sunday that New York is struggling to maintain medical supplies while combatting the novel coronavirus — operating "literally" on a "day-to-day" basis.

Why it matters: New York City has become an epicenter of the coronavirus outbreak, and is facing mass quarantines and stay-at-home orders. Cuomo said Saturday that New York reported 630 new deaths in 24 hours — an "all-time increase" that beat the previous day's record of 562 deaths.

Coronavirus dashboard

Illustration: Sarah Grillo/Axios

  1. Global: Total confirmed cases as of 11 a.m. ET: 1,225,360 — Total deaths: 66,542 — Total recoveries: 252,615Map.
  2. U.S.: Total confirmed cases as of 11 a.m. ET: 312,249 — Total deaths: 8,503 — Total recoveries: 15,021Map.
  3. Public health latest: CDC launches national trackers and recommends face coverings in public. Federal government will cover costs of COVID-19 treatment for uninsured. Surgeon general says this week will be "our Pearl Harbor, our 9/11 moment."
  4. 2020 latest: "We have no contingency plan," Trump said on the 2020 Republican National Convention. "We're having the convention at the end of August." Biden says DNC may have to hold virtual convention.
  5. States updates: The Louisiana governor warned that his state is set to run out of ventilators in four days. Illinois governor claims Trump doesn't understand the word "federal."
  6. Oil latest: Monday meeting among oil-producing countries to discuss supply curbs is reportedly being delayed amid tensions between Saudi Arabia and Russia.
  7. Work update: Employees still going to work are often facing temperature checks, distanced work stations, protective devices and mass absences.
  8. What should I do? Pets, moving and personal health. Answers about the virus from Axios expertsWhat to know about social distancingQ&A: Minimizing your coronavirus risk.
  9. Other resources: CDC on how to avoid the virus, what to do if you get it.

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Illinois governor: "The president does not understand the word 'federal'"

Illinois Gov. J.B. Pritzker said on CNN's "State of the Union" Sunday that President Trump's comments about the federal government's stockpile of medical equipment suggest he "does not understand the word 'federal.'"

Why it matters: White House adviser Jared Kushner argued at a press briefing last week that the "notion of the federal stockpile was it’s supposed to be our stockpile; it’s not supposed to be state stockpiles that they then use."