Cancer is a dreaded disease. People often worry more about getting cancer than heart disease, the No. 1 killer more likely to take their lives. Indeed, Mutual of Omaha sent me applications for cancer coverage on several occasions. I’ve heard those policies are very profitable for insurance companies because people far over-estimate their risk of cancer. By contrast, I’ve never seen an insurance policy that only covered heart disease.
In 2022 about 1.9 million Americans were diagnosed with cancer. That same year more than 609,000 died. Of cancer deaths lung cancer is the most common accounting for 21% of deaths. Colon and rectal cancer deaths are the second most common (9%). Pancreatic cancer is third (8%), while at 7% of cancer deaths are due to breast cancer, which comes in fourth. While we’ve all heard of these four common cancers, they account for less than half (45%) of all cancer deaths. That means other cancers account for more than half (55%) of all cancer deaths.
Historically there were only a few cancer screening tests. For instance, mammography screens for breast cancer. The prostate-specific antigen test, or PSA, screens for prostate cancer. Colonoscopy identifies polyps that can turn into colon cancer, while high risk individuals who smoke may get an x-ray for lung cancer. Another cancer screening test is for cervical cancer. That leaves the vast majority of cancers not routinely screened for.
This from Wired magazine:
Of the more than 200 types of cancer, we currently only screen for cervical, breast, and bowel cancer, says Kumar. He calls this the streetlight problem: “We’re looking for cancer in the light, but four-fifths are happening in the dark.” But even if we did check for all these cancers, people aren’t going to turn up for 200 screenings. “We cannot continue the paradigm of looking for these cancers one at a time,” he says.
Cancer is usually treatable if caught early. The cancers that are the deadliest (such as pancreatic cancer) are lethal because they are difficult to catch early. Many deadly cancers have no symptoms until they’ve spread. About 90% of cancer deaths are due to metastatic cancer, that is cancer that has spread beyond the original location. In theory most cancer could be treatable if only it could be caught sooner, before it has a chance to spread.
A new company named Grail has a blood test capable of detecting numerous cancers at the same time rather than testing for one at a time. It tests for cancer DNA in the blood. According to an interview by Wired magazine with Harpal Kumar president of the European branch of Grail:
The dream is a single test that can identify every cancer from a single draw of blood—and that’s roughly what Grail has been developing: a test that is sensitive to early stage cancers, can detect and locate many different cancer types, gives very few false positives, and can hone in on the most serious cancers.
Galleri is the result. The company says it can detect more than 50 types of cancer with a single blood sample. Just as regular cells shed DNA when they die, so do tumor cells, and this DNA is traceable in the blood. The test has been validated by Grail in clinical trials: If the test detects something, there’s a 45 percent likelihood that it’s cancer—an extremely high predictive rate for a cancer test. Galleri says it can predict where a cancer is in the body with 90 percent accuracy.
The test called Galleri has been available in the U.S. for about a year and a half and costs $949. That sounds like a bargain if it works. That reminds me of something that John Goodman wrote years ago (see paragraph 10), ”[W]e could spend our entire gross domestic product on healthcare in useful ways. In fact, we could probably spend the entire GDP on diagnostic tests alone—without ever treating a real disease.”
About 25 years ago the National Center for Policy Analysis published a policy report on the cost per life-year saved by various interventions. The cost varies from low-hanging fruit (cheap, highly effective interventions like seatbelts, smoking cessation and childhood immunizations) to extremely costly environmental interventions. I wonder how many Galleri tests would be required to save a year of life? I doubt if the calculation has been done. If testing is done on low-risk individuals, the cost of buying a year of life could be in the billions. Testing like this is not something that Medicare or private insurance would pay for but doesn’t mean it’s not beneficial. It could provide peace of mind to people whose family have a history of cancer or peace of mine for the worried well.
Virtually all preventive medical screening tests have a positive cost per year of life saved. That means you are spending money rather than saving money. There are virtually none that save money. Yet year after year I read where politicians or public health advocates (often the news media) argues for more preventive medical interventions as a way to lower health care spending. But that does not save money. That’s not to say prevention is a bad deal, just it does not save money. The upside of Galleri is that you may discover cancer early enough that it’s easily cured. The downside of Galleri is that you could get a false positive that requires thousands in further testing to discover you never had cancer.