Some experts question the usefulness of Pap testing going forward. But how would cutting back on Pap testing affect clinical laboratory revenue and is it safe for cancer patients?
Recently, a major medical society issued its findings that cervical cancer in the United States has been on a sustained decline for more than a decade and a half. This confirms what cytopathologists and cytotechnologists have watched as the development of new clinical laboratory tests, and the introduction of a vaccine for HPV (human papillomavirus) about 15 years ago, contributed to a reduction in the number of cervical cancer deaths annually here in the United States and in several other nations.
As incidences of cervical cancer declined, so have orders for Pap tests. Thus, clinical laboratory revenues in this area also have declined. This is a change from the 1990s and early 2000s, when Pap tests were the primary screening tool for cervical cancer. About 55 million Pap tests were performed annually during those years and many labs maintained sizeable numbers of cytotechs to perform these tests.
HPV Testing Drove Decreases in Cervical Cancer, Decline in Pap Testing
For at least the past decade, there are pathologists, cytotechnologists, and medical laboratory scientists who graduated from their training programs and began working in labs unaware that, since the 1990s, conventional Pap testing as a major source of test referrals and revenue for clinical laboratories and pathology groups has been on the decline.
What is the reason for the decline? Advances in several areas of medicine, implemented over the past 25 years, have greatly altered how we screen for cervical cancer today. And, in a stepwise fashion, the HPV test and HPV vaccine steadily reduced the role of Pap tests as a primary screening tool.
HPV, a common sexually-transmitted virus, is linked to not only cervical cancer, but also cancers of the vulva, vagina, penis, and anus, according to the Centers for Disease Control and Prevention (CDC) data, which recorded 43 million HPV infections in the US in 2018.
“It is likely that the significant decrease in cervical cancer incidence (in the US) results from clear guidelines for cervical cancer screening and may also reflect promotion and acceptance of [HPV] vaccination, particularly in younger women,” said the ASCO study’s lead author Cheng-I Liao, MD (above), in a news release. Liao is affiliated with Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan. (Photo copyright: Healio.)
Cervical Cancer Down, But Other HPV Cancers Up
Though cervical cancer incidence is down, other HPV-related cancers may need additional screening standards to head off rising cancer cases, the ASCO study suggests.
To conduct their study, the ASCO researchers analyzed data for 657,317 people in the US Cancer Statistics (USCS) program from 2001 to 2017. The researchers reported their findings at the 2021 ASCO Annual Meeting held online in June. They include:
Cervical cancer incidence rate decreased each year by 1.03% annually over 16 years.
In the 20 to 24 age group, a “disproportionately higher decrease” of 4.6% per year in cervical cancer incidence rate suggested “potential effect of vaccinations.”
Without screenings, HPV-related cancers incidence increased in women over 16 years.
Oropharyngeal, anal, rectal, and vulvar cancer increased 1.3% in women per year.
In men, oropharyngeal cancer incidence represented 81% of all HPV-related cancers—five times more than cases for women over 16 years.
HPV-related cancers in men increased 2.36% per year over 16 years, and oropharyngeal cancer had the biggest increase.
“Without standardized screening, HPV-related cancers—such as oropharyngeal cancers and anal rectal cancers—are increasing. To reduce these trends and achieve success comparable to what we’re seeing with cervical cancer we must develop effective screening strategies and determine vaccine efficacy in these patient populations,” Liao said in the news release.
Should PAP Tests Be Dropped as a Primary Screen for Cervical Cancer?
Today’s American Cancer Society (ACS) guidelines for cervical cancer screening denote the primary (FDA-designated) HPV test as the “preferred test” for people 25 to 65 years of age. A Pap test (or Pap smear) can be done at the same time, or in instances when a primary HPV test is not available, the ACS said.
HPV screening aims to detect high risk strains of HPV by looking for DNA in cervical cells and the Pap test involves collecting cells from the cervix for review in the medical laboratory for cancer and pre-cancer, the ACS added.
However, pathologists and cytotechnologists who have examined Pap smear slides for many years know that indications of cervical cancer are not always detected by HPV screening. A Pap test often picks up indications of cervical cancer that might not have been detected by the HPV test.
One reason is HPV tests only monitor about 20 of the genetic mutations known to cause cervical cancer. There are about 80 mutations that can cause cervical cancer, but most are so rare, it does not pay to include them in the HPV test panel.
“The Pap is not something that we should look at as replaceable. In some circumstances, we can get a Pap smear that has some significant cellular changes on it,” Jessica Shepherd, MD, an obstetrician and gynecologist at Baylor University Medical Center in Dallas, told USA Today.
Medicine Advancing, Pap Referrals Not So Much
In the 1990s, Pap tests were the front line for cervical cancer screening and a source of about 55 million referrals to clinical laboratories each year, recalls Robert Michel, Editor-in-Chief of Dark Daily and its sister publication The Dark Report.
“Interestingly, in the past decade, many cytotechnologists and laboratory scientists who started work in labs at the time of the new HPV screening guidelines and vaccination were unaware of the Pap test’s impact on revenue for clinical labs and pathology groups,” he said.
Medical advancements over the past 25 years have altered how providers screen women for cervical cancer and help them prevent it. And as HPV screening and HPV vaccination gained prominence, the standard Pap test became a kind of “co-pilot” to HPV testing. Unfortunately, this meant less oncology referrals to medical labs.
Silicon Valley startup is using gene sequencing to identify in the bloodstream free-floating genetic material shed by tumors
There has been plenty of excitement about the new diagnostic technologies designed to identify circulating tumor cells in blood samples. Now, a well-funded Silicon Valley startup has developed a blood test that it says holds promise for detecting early-stage lung and other cancers.
Though experimental, the screening test—which uses gene sequencing to identify in the bloodstream cancer-signaling genetic material shed by tumors—would be a boon for clinical laboratories and health networks. It also could play a role in advancing precision medicine treatments and drug therapies.
GRAIL, a Menlo Park, Calif., life sciences company, presented its initial findings at the 2018 American Society of Clinical Oncology Annual Meeting in Chicago. Its lung cancer data is part of GRAIL’s ongoing Circulating Cell-Free Genome Atlas (CCGA) study, which aims to enroll 15,000 participants and investigate 20 different types of cancers.
“We’re excited that the initial results for the CCGA study show it is possible to detect early-state lung cancer from blood samples using genome sequencing,” said lead study author Geoffrey Oxnard, MD, Dana-Farber Cancer Institute and Associate Professor of Medicine at Harvard Medical School, in a Dana-Farber news release.
“There is an unmet need globally for early-detection tests for lung cancer that can be easily implemented by healthcare systems,” lead study author Geoffrey Oxnard, MD (above), said in the Dana-Farber news release. “These are promising early results and the next steps are to further optimize the assays and validate the results in a larger group of people.” (Photo copyright: Dana-Farber Cancer Institute.)
According to the news release, researchers in this initial analysis explored the ability of three different prototype sequencing assays, each with 98% specificity, to detect lung cancer in blood samples:
Whole-genome bisulfite sequencing (WGBS) detected 41% of early-stage (stage 1-3A) lung cancers and 89% of late-stage (stage 3B-4) lung cancers;
Whole-genome sequencing (WGS) detected 38% of early-stage cancers and 87% of late-stage cancers; and,
Targeted sequencing detected 51% of early-stage cancers and 89% of late-stage cancers.
“The initial results showed that all three assays could detect lung cancer with a low rate of false positives (in which a test indicates a person has cancer when there is no cancer),” the Dana-Farber news release noted.
Identifying Disease Risk Before Symptoms Appear
Screening tests help identify individuals who are not displaying disease symptoms but may be at high risk for developing a disease. GRAIL’s goal is to develop a test with a specificity of 99% or higher. This means no more than one out of 100 people would receive a false-positive.
Otis Brawley, MD, Chief Medical and Scientific Officer at the American Cancer Society, points out that specificity is important when developing a population-based screening test that ultimately would be given to large portions of the general public based on age, medical history, or other factors.
“I am much more concerned about specificity than sensitivity [true positive rate], and [GRAIL] exhibited extremely high specificity,” Brawley told Forbes. “You don’t want a lot of false alarms.”
Some cancer experts have a wait-and-see reaction to GRAIL’s initial results, due in part to the small sample size included in the sub-study. Benjamin Davies, MD, Associate Professor of Urology at the University of Pittsburgh School of Medicine, and an expert on prostate cancer screening, told Forbes the early data was “compelling,” but the number of patients in the study was too small to generate excitement.
Oxnard, however, believes the initial results validate the promise of GRAIL’s blood screening test project.
“I was a skeptic two years ago,” Oxnard, a GRAIL consultant, told Forbes. “I think these data need to put a lot of the skepticism to rest. It can be done. This is proof you can find cancer in the blood, you can find advanced cancer, therefore this has legs. This has a real future. It’s going to be many steps down the line, but this deserves further investigation and should move forward.”
Next Steps
Researchers next plan to verify the initial results in an independent group of 1,000 CCGA participants as part of the same sub-study. They then will attempt to optimize the assays before validating them in a larger data set from CCGA, the Dana-Farber news release explained.
Illumina, a sequencing-technology developer, formed GRAIL in 2016, with participating investments from Bill Gates, Bezos Expeditions and Sutter Hill Ventures. Since then, GRAIL has attracted other high-flying investors, including Amazon, Merck, Johnson and Johnson, and Bristol-Myers Squibb.
Forbes notes that as of 2018 GRAIL has raised $1.6 billion in venture capital and has a $3.2 billion valuation, according to private market data firm Pitchbook. Last year, GRAIL merged with Hong Kong-based Cirina Ltd., a privately held company also focused on the early detection of cancer.
While GRAIL’s projects hold promise, anatomic pathologists and clinical laboratories may be wise to temper their enthusiasm until more research is done.
“We all would like to dream that someday you’d be able to diagnose cancer with a blood test,” Eric Topol, MD, Executive Vice President and Professor of Molecular Medicine at Scripps Research, told Forbes. Topol says he’s “encouraged” by GRAIL’s methodical approach, but warns: “We’re at the earliest stage of that.”
As the public gains awareness of the role clinical laboratories play in modern healthcare, increased engagement and understanding of the technology underlying many of these advances could create risk for labs without transparent reporting protocols to both patients and the public
In recent years, consumers have continually raised the bar in their expectation of quality when they interact with the healthcare system. Not only do patients expect providers—including clinical laboratories and anatomic pathology groups—to improve regularly over time, but the public has even less tolerance for medical errors of any type. Thus, a recent NPR story is one more warning to the medical laboratory profession that it should be devoting resources and effort to improving quality.
Today’s healthcare consumers and patients are more educated about and involved in the care process than ever before. While the exact science and skills may not interest the general public, the technologies underpinning much of the shift toward personalized medicine (AKA, precision medicine) are the same technologies that created the always-connected, digital lifestyles seen around the world.
With this, comes a level of scrutiny and questioning from the public that clinical laboratories or anatomic pathology groups would not have experienced even just a decade ago.
Mounting Scrutiny of Medical Laboratories and Healthcare Professionals
A recent segment on NPR’s “All Things Considered” highlighted this trend and questioned the quality control standards behind many of the procedures powering current testing. The segment also questioned the impact quality control has on the quality of biobanks used to research and create future technologies and tests.
Atul Butte, PhD (above), Director of the Institute of Computation Health Sciences at the University of California-San Francisco, presents an alternate side to Compton and Friedberg’s views in the NPR article. “I am not a believer in garbage-in, garbage out at all,” he said. “I know that no one scientist, no one clinician or pathologist is perfect … But, I’d rather take 10 or 100 so-called mediocre data sets and find out what’s in common, then to take one who says they’re perfect at doing this kind of measurement.” (Photo copyright: Santiago Mejia/San Francisco Chronicle.)
When data and previous research powers much of the innovation taking place across the modern healthcare landscape, the accuracy of said data would seem critical. Yet, without standards in place, there’s not always safeties by which to verify sample integrity and other critical concerns.
Late last year, Dark Daily reported on a study published in PLOS ONE from Radboud University in the Netherlands questioning the accuracy of more than 30,000 published scientific studies that contained misidentified or contaminated cell lines. Guidelines, such as those created for IHR and FISH HER2 testing, provide standards intended to prevent such issues from occurring or detecting them when they do occur.
Quality versus Quantity: A Gamble Worth Taking?
Apart from challenges with healthcare reform and the regulatory landscape surrounding precision medicine, medical laboratories also must struggle with the challenges of gleaning and maintaining useful, accurate information from an ever-growing trove of data produced by analyzers and assays.
Yet, these mediocre datasets include the results of tests that carried a potentially significant impact on patient lives. In the first two weeks of February alone, both the St. Louis Post-Dispatch and The Telegraph published stories related to erroneous testing related to cancer and the potential impact on the clinical laboratories involved and the patients tested.
Increased coverage shows that the world is watching what goes on in medical laboratories, hospitals, and data centers as healthcare continues to evolve. Clinical laboratories must move forward with this in mind or risk pushback and questioning from the public. Transparency regarding standards, and reporting information to patients surrounding testing or concerns, might effectively address this rising trend.
“We are moving faster and faster and faster as this whole precision medicine train is moving down the track,” Tim Allen, MD, Laboratory Director at the University of Texas Medical Branch Department of Laboratory Services, told NPR. “I suspect standardization of these things is going to become a reality much quicker than I would have expected even a few years ago.”
That quality control issues in anatomic pathology are considered newsworthy by no less than NPR is a sign of increased public attention to the quality of lab testing. The story was written to educate the public about the gap that exists in the quality control of anatomic pathology testing. All of this is consistent with the trend for providers to be transparent and report their quality metrics to the public, including patients.
This finding is reinforced by the fact that high-deductible health plans are now the second most popular plan option offered by the nation’s employers
Getting paid for expensive genetic cancer tests is likely to be tougher for clinical laboratories when the patient is covered by a high-deductible health plan. There are two trends that are contributing to this situation, each highlighted by recently-published studies.
One trend is the rapid growth of consumer-driven health plans (CDHPs). The second trend is growing evidence that patients, if they need to pay much money out of pocket, will decline to undergo genetic testing that is suggested by their physicians. (more…)
Times reporter looks at issues affecting accuracy of different breast cancer tests
Pathologists should consider a recent story about breast cancer testing in the New York Times to be a warning flag, similar to the warning flags that the Coast Guard flies along the coast to warn of an approaching hurricane. The subject of the story was “unclear tests” used to identify whether a breast cancer patient is a candidate for certain therapeutic drugs.
The New York Times story was in response to the public release of new guidelines for processing specimens used in estrogen receptor and progesterone receptor (ER/PR) testing for breast cancer. The guidelines were announced by the College of American Pathologists and American Society of Clinical Oncology (ASCO) on April 19, 2010. One goal of the new guidelines is to improve “the accuracy of immunohistochemistry (IHC) testing for the expression status of estrogen (ER) and progesterone receptors (PgR) in breast cancer” as performed by the hundreds of anatomic pathology laboratories in the United States which perform ER and PR testing.
