It was easy fodder for newsroom editors, the stuff of click-generating headlines.
At the British Science Festival on Sept. 6, 2016, professor Gareth Jenkins of Swansea University presented research into a “new test” that “could revolutionize cancer diagnosis.”1
Professor Jenkins likened the test to a “cancer smoke detector” because it “detects cancer by detecting the ‘smoke’ — the mutated blood cells,” or changes in red blood cell surface proteins.1
Last week, I took issue with the analogy. Is not smoke a symptom of fire?
A better system would, for example, identify flaws or deterioration in electrical wiring that could spark a blaze and destroy a home.
At the same time, the discovery of a potential early warning blood test for cancer seems like a big deal.
Over the course of four years and more than 300 patients, professor Jenkins and his team were able to use the test to identify three separate groups among those tested: totally healthy volunteers, a group with pre-cancer of the esophagus and those with esophageal cancer.1
The existing test for the precursor condition of esophageal cancer — which has one of the worst prognoses of all cancers — is a nonsurgical, though pretty invasive, procedure known as an endoscopy.
An endoscope is a long, flexible tube with a light and camera attached to it. A specialist slides it down your throat to get pictures of your digestive system, including the esophagus, the stomach and the beginning of the small intestine.2
What professor Jenkins described last week detects a red blood cell mutation via a simple blood test.
The particular change detected doesn’t actually contribute to the development of cancer. But mutation is the critical event in the process that leads to cancer.
The starting point for the Swansea University team was what’s known as the PIGA gene mutation.
Their initial findings were actually published back on Feb. 25, 2016, by The Lancet:
The application of this simple, blood-based assay in people with gastro-oesophageal reflux demonstrated greater levels of DNA damage in patients with oesophageal adenocarcinoma than in patients with Barrett’s oesophagus or reflux alone. The PIGA gene mutation assay has the potential to be a biomonitoring tool in both Barrett’s oesophagus and other premalignant conditions.3
PIGA has been a focal point of research into identifying people at higher risk of developing cancer for at least 10 years.4
Said Dr. David J. Araten of the New York University School of Medicine back in 2005: “The mutation rate is widely believed to be a critical factor in the development of cancer, but it’s been extremely difficult to study in human cells.”
That 2005 study concluded that “the chance of a mutation in the PIGA gene each time a cell divides ranges from about one in 3 million to about one in 300,000 in cells from individuals without a genetic predisposition to cancer.”
But among groups with DNA defects that predispose them to cancer, the probability of mutations was one in 20,000 to 100,000 per cell division.
Professor Jenkins’ study at Swansea found “only a few mutated cells” per million red blood cells from healthy volunteers, an average of approximately 5 per million.
Cancer patients should have 50 to 100 mutations per million.
Several biotech firms have spent years researching a useful early warning system for cancer.
It’s still way too early to trumpet too loudly the Swansea findings, though I couldn’t get the news stories out of my head last Sunday, particularly as I watched my favorite English football club, Chelsea, take on its Premier League rivals, Swansea City.
So I had Swansea on the brain.
And I kept thinking about a quote from a May 13, 2016, story by Katharine Hobson for FiveThirtyEight.com regarding what we need to know and when we need to know it when it comes to treating diseases, including cancer.5
Hobson referenced another FiveThirtyEight.com story, by Christie Aschwanden, that made “The Case Against Early Cancer Detection“:
The harder we look for cancer — any cancer — the more we find. But most of these extra cases are ones like papillary thyroid cancers that never pose a threat. Researchers have a name for this — overdiagnosis, and it leads to another problem, overtreatment.6
Aschwanden’s evidence was South Korea, where incidence of thyroid cancer has spiked over the last two decades… due largely to a “high-tech health care system” that’s driven a rapid increase in diagnoses.
Since 1999, South Korea has provided free cancer screening to its patients. The test for thyroid cancer is a cheap add-on to that program. Alas, as Aschwanden notes:
As a result, the number of Koreans getting screened for thyroid cancer has soared.
That might sound great. But the good news about this epidemic — death rates from thyroid cancer have remained flat (and low), despite the skyrocketing number of diagnoses — is also the bad news. Ideally, screenings should lead to a decrease in cancer deaths. But not in South Korea.6
A year ago, privately held Pathway Genomics generated headlines after the Food and Drug Administration (FDA) sent the San Diego-based company a letter expressing concern about the efficacy of CancerIntercept Detect.7
The FDA noted that Pathway positioned CancerIntercept as a noninvasive blood test to screen for up to 10 different types of cancer in high-risk populations.
This is the type of scattershot approach that puts more pressure on the healthcare system and simply raises emotional tension without a corresponding benefit.
What Professor Jenkins and his Swansea team have done is more specific, focused on a treatable but rarely curable malignancy, esophageal cancer, where early warning may indeed lead to more positive patient outcomes.
But it’s still way too early to claim any victories.
This Week In…
Someone sent a wind-up robot tottering into a nest of Australian bull ants, a species “characterized by their extreme aggressiveness, ferocity, and painful stings.” It’s a delight to watch these formicidaen bullies spend themselves impotently on the unfeeling skin of a toy, thus proving the superiority of humans over jerky ants.
Editorial Director, Wall Street Daily