A blood test may catch colorectal cancer before it's too late
Soon it may be possible to find different types of cancer earlier than ever through a simple blood test.
Among the many blood tests in development, researchers announced in July that they have developed one that may screen for early-onset colorectal cancer. The new potential screening tool, detailed in a study in the journal Gastroenterology, represents a major step in noninvasively and inexpensively detecting nonhereditary colorectal cancer at an earlier and more treatable stage.
In recent years, this type of cancer has been on the upswing in adults under age 50 and in those without a family history. In 2021, the American Cancer Society's revised guidelines began recommending that colorectal cancer screenings with colonoscopy begin at age 45. But that still wouldn’t catch many early-onset cases among people in their 20s and 30s, says Ajay Goel, professor and chair of molecular diagnostics and experimental therapeutics at City of Hope, a Los Angeles-based nonprofit cancer research and treatment center that developed the new blood test.
“These people will mostly be missed because they will never be screened for it,” Goel says. Overall, colorectal cancer is the fourth most common malignancy, according to the U.S. Centers for Disease Control and Prevention.
Goel is far from the only one working on this. Dozens of companies are in the process of developing blood tests to screen for different types of malignancies.
Some estimates indicate that between one-fourth and one-third of all newly diagnosed colorectal cancers are early-onset. These patients generally present with more aggressive and advanced disease at diagnosis compared to late-onset colorectal cancer detected in people 50 years or older.
To develop his test, Goel examined publicly available datasets and figured out that changes in novel microRNAs, or miRNAs, which regulate the expression of genes, occurred in people with early-onset colorectal cancer. He confirmed these biomarkers by looking for them in the blood of 149 patients who had the early-onset form of the disease. In particular, Goel and his team of researchers were able to pick out four miRNAs that serve as a telltale sign of this cancer when they’re found in combination with each other.
The blood test is being validated by following another group of patients with early-onset colorectal cancer. “We have filed for intellectual property on this invention and are currently seeking biotech/pharma partners to license and commercialize this invention,” Goel says.
He’s far from the only one working on this. Dozens of companies are in the process of developing blood tests to screen for different types of malignancies, says Timothy Rebbeck, a professor of cancer prevention at the Harvard T.H. Chan School of Public Health and the Dana-Farber Cancer Institute. But, he adds, “It’s still very early, and the technology still needs a lot of work before it will revolutionize early detection.”
The accuracy of the early detection blood tests for cancer isn’t yet where researchers would like it to be. To use these tests widely in people without cancer, a very high degree of precision is needed, says David VanderWeele, interim director of the OncoSET Molecular Tumor Board at Northwestern University’s Lurie Cancer Center in Chicago.
Otherwise, “you’re going to cause a lot of anxiety unnecessarily if people have false-positive tests,” VanderWeele says. So far, “these tests are better at finding cancer when there’s a higher burden of cancer present,” although the goal is to detect cancer at the earliest stages. Even so, “we are making progress,” he adds.
While early detection is known to improve outcomes, most cancers are detected too late, often after they metastasize and people develop symptoms. Only five cancer types have recommended standard screenings, none of which involve blood tests—breast, cervical, colorectal, lung (smokers considered at risk) and prostate cancers, says Trish Rowland, vice president of corporate communications at GRAIL, a biotechnology company in Menlo Park, Calif., which developed a multi-cancer early detection blood test.
These recommended screenings check for individual cancers rather than looking for any form of cancer someone may have. The devil lies in the fact that cancers without widespread screening recommendations represent the vast majority of cancer diagnoses and most cancer deaths.
GRAIL’s Galleri multi-cancer early detection test is designed to find more cancers at earlier stages by analyzing DNA shed into the bloodstream by cells—with as few false positives as possible, she says. The test is currently available by prescription only for those with an elevated risk of cancer. Consumers can request it from their healthcare or telemedicine provider. “Galleri can detect a shared cancer signal across more than 50 types of cancers through a simple blood draw,” Rowland says, adding that it can be integrated into annual health checks and routine blood work.
Cancer patients—even those with early and curable disease—often have tumor cells circulating in their blood. “These tumor cells act as a biomarker and can be used for cancer detection and diagnosis,” says Andrew Wang, a radiation oncologist and professor at the University of Texas Southwestern Medical Center in Dallas. “Our research goal is to be able to detect these tumor cells to help with cancer management.” Collaborating with Seungpyo Hong, the Milton J. Henrichs Chair and Professor at the University of Wisconsin-Madison School of Pharmacy, “we have developed a highly sensitive assay to capture these circulating tumor cells.”
Even if the quality of a blood test is superior, finding cancer early doesn’t always mean it’s absolutely best to treat it. For example, prostate cancer treatment’s potential side effects—the inability to control urine or have sex—may be worse than living with a slow-growing tumor that is unlikely to be fatal. “[The test] needs to tell me, am I going to die of that cancer? And, if I intervene, will I live longer?” says John Marshall, chief of hematology and oncology at Medstar Georgetown University Hospital in Washington, D.C.
Ajay Goel Lab
A blood test developed at the University of Texas MD Anderson Cancer Center in Houston helps predict who may benefit from lung cancer screening when it is combined with a risk model based on an individual’s smoking history, according to a study published in January in the Journal of Clinical Oncology. The personalized lung cancer risk assessment was more sensitive and specific than the 2021 and 2013 U.S. Preventive Services Task Force criteria.
The study involved participants from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial with a minimum of a 10 pack-year smoking history, meaning they smoked 20 cigarettes per day for ten years. If implemented, the blood test plus model would have found 9.2 percent more lung cancer cases for screening and decreased referral to screening among non-cases by 13.7 percent compared to the 2021 task force criteria, according to Oncology Times.
The conventional type of screening for lung cancer is an annual low-dose CT scan, but only a small percentage of people who are eligible will actually get these scans, says Sam Hanash, professor of clinical cancer prevention and director of MD Anderson’s Center for Global Cancer Early Detection. Such screening is not readily available in most countries.
In methodically searching for blood-based biomarkers for lung cancer screening, MD Anderson researchers developed a simple test consisting of four proteins. These proteins circulating in the blood were at high levels in individuals who had lung cancer or later developed it, Hanash says.
“The interest in blood tests for cancer early detection has skyrocketed in the past few years,” he notes, “due in part to advances in technology and a better understanding of cancer causation, cancer drivers and molecular changes that occur with cancer development.”
However, at the present time, none of the blood tests being considered eliminate the need for screening of eligible subjects using established methods, such as colonoscopy for colorectal cancer. Yet, Hanash says, “they have the potential to complement these modalities.”
More than 20 percent of American adults suffer from chronic pain. And as many as one in four of those prescribed opioids to manage that pain go on to misuse – or abuse – them, often with devastating consequences. Patients afflicted by both chronic pain and opioid addiction are especially difficult to treat, according to Eric Garland, PhD, Director of the University of Utah’s Center on Mindfulness and Integrative Health Intervention Development, because opioid overuse increases pain sensitivity, and pain promotes relapse among those being treated for addiction.
A new study, however, shows that a mindfulness-based therapy can successfully tackle both problems at once, pointing to a tool that could potentially help in fighting the opioid crisis. “This is the first large-scale clinical trial to show that any psychological intervention can reduce opioid misuse and chronic pain for the long term,” says Garland, lead author of the study, published February 28th in JAMA Internal Medicine.
Garland’s study focused on 250 adults who had received opioid therapy for chronic pain for 90 days or longer, randomly assigning them to eight weeks of either a standard psychotherapy support group or Mindfulness-Oriented Recovery Enhancement (MORE) therapy, which combines mindfulness training, cognitive-behavioral therapy (CBT) and positive psychology. Nine months after getting these treatments in primary care settings, 45 percent of patients in the MORE group were no longer misusing opioids, compared to 24 percent of those in group therapy. In fact, about a third of the patients in the MORE group were able to cut their opioid dose in half or reduce it even further.
Patients treated with MORE also experienced more significant pain relief than those in support groups, according to Garland. Conventional approaches to treating opioid addiction include 12-step programs and medically-assisted treatment using drugs like methadone and Suboxone, sometimes coupled with support groups. But patients with Opioid Use Disorder (OUD) – the official diagnosis for opioid addiction – have high relapse rates following treatment, especially if they have chronic pain.
While medically-assisted treatments help to control drug cravings, they do nothing to control chronic pain, which is where psychological therapies like MORE come in.
“For patients suffering from moderate pain and OUD, the relapse rate is three times higher than in patients without chronic pain; for those with severe chronic pain, the relapse rate is five times higher,” says Amy Wachholtz, PhD, Director of Clinical Health Psychology and associate professor at University of Colorado in Denver. “So if we don’t treat the chronic pain along with the OUD addiction simultaneously, we are setting patients up for failure.”
Unfortunately, notes Garland, the standard of care for patients with chronic pain who are misusing their prescribed painkillers is “woefully inadequate.” Many patients don’t meet the criteria for OUD, he says, but instead fall into a gray zone somewhere between legitimate opioid use and full-blown addiction. And while medically-assisted treatments help to control drug cravings, they do nothing to control chronic pain, which is where psychological therapies like MORE come in. But behavioral therapies are often not available in primary care settings, and even when clinicians do refer patients to behavioral health providers, they often prescribe CBT. A large scale study last year showed that CBT – without the added components of mindfulness training and positive psychology – reduced pain but not opioid misuse.
Psychotherapist Eric Garland teaches mindfulness.
University of Utah
Reward Circuitry Rewired
Opioids are highly physiologically addictive. Repeated and high-dose drug use causes the brain to become hypersensitive to stress, pain, and drug-related cues, such as the sight of one’s pill bottle, says Garland, while at the same time becoming increasingly insensitive to natural pleasures. “As an individual becomes more and more dependent on the opioids just to feel okay, they feel less able to extract a healthy sense of joy, pleasure and meaning out of everyday life,” he explains. “This drives them to take higher and higher doses of the opioid to maintain a dwindling sense of well-being.”
The changes are not just psychological: Chronic opioid use actually causes changes in the brain’s reward circuitry. “You can see on brain imaging,” says Garland. “The brain’s reward circuitry becomes more responsive when a person is viewing opioid related images than when they are viewing images of smiling babies, lovers holding hands, or sunsets over the beach.” MORE, he says, teaches “savoring” – a tenet of positive psychology – as a means of restructuring the reward processes in the brain so the patient becomes sensitive to pleasure from natural, healthy rewards, decreasing cravings for drug-related rewards.
Mindfulness and Addiction
Mindfulness, a form of meditation that teaches people to observe their feelings and sensations without judgement, has been increasingly applied to the treatment of addiction. By observing their pain and cravings objectively, for example, patients gain increased awareness of their responses to pain and their habits of opioid use. “They learn how to be with discomfort, whether emotional or physical, in a more compassionate way,” says Sarah Bowen, PhD, associate professor of psychology at Pacific University in Oregon. “And if your mind gives you a message like ‘Oh, I can’t handle that,’ to recognize that that’s a thought that might not be true.”
Bowen’s research is focused on Mindfulness-Based Relapse Prevention, which addresses the cravings associated with addiction. She has patients practice what she calls “urge surfing”: riding out a craving or urge rather than relying on a substance for immediate relief. “Craving will happen, so rather than fighting it, we look at understanding it better,” she says.
MORE differs from other forms of mindfulness-based therapy in that it integrates reappraisal and savoring training. Reappraisal is a technique often used in CBT in which patients learn to change negative thought patterns in order to reduce their emotional impact, while savoring helps to restructure the reward processes in the brain.
Mindfulness training not only helps patients to understand and gain control over their behavior in response to cravings and triggers like pain, says Garland, but also provides a means of pain relief. “We use mindfulness to zoom into pain and break it down into its subcomponents – feelings of heat or tightness or tingling – which reduces the impact that negative emotions have on pain processing in the brain.”
Eric Garland examines brain waves.
University of Utah
Powerful interventions
As the dangers of opioid addiction have become increasingly evident, some scientists are developing less addictive, non-opioid painkillers, but more trials are needed. Meanwhile, behavioral approaches to chronic pain relief have continued to gain traction, and researchers like Garland are probing the possibilities of integrative treatments to treat the addiction itself. Given that the number of people suffering from chronic pain and OUD have reached new heights during the COVID-19 pandemic, says Wachholtz, new treatment alternatives for patients caught in the relentless cycle of chronic pain and opioid misuse are sorely needed. “We’re trying to refine the techniques,” she says, “but we’re starting to realize just how powerful some of these mind-body interventions can be.”
Exactly 67 years ago, in 1955, a group of scientists and reporters gathered at the University of Michigan and waited with bated breath for Dr. Thomas Francis Jr., director of the school’s Poliomyelitis Vaccine Evaluation Center, to approach the podium. The group had gathered to hear the news that seemingly everyone in the country had been anticipating for the past two years – whether the vaccine for poliomyelitis, developed by Francis’s former student Jonas Salk, was effective in preventing the disease.
Polio, at that point, had become a household name. As the highly contagious virus swept through the United States, cities closed their schools, movie theaters, swimming pools, and even churches to stop the spread. For most, polio presented as a mild illness, and was usually completely asymptomatic – but for an unlucky few, the virus took hold of the central nervous system and caused permanent paralysis of muscles in the legs, arms, and even people’s diaphragms, rendering the person unable to walk and breathe. It wasn’t uncommon to hear reports of people – mostly children – who fell sick with a flu-like virus and then, just days later, were relegated to spend the rest of their lives in an iron lung.
For two years, researchers had been testing a vaccine that would hopefully be able to stop the spread of the virus and prevent the 45,000 infections each year that were keeping the nation in a chokehold. At the podium, Francis greeted the crowd and then proceeded to change the course of human history: The vaccine, he reported, was “safe, effective, and potent.” Widespread vaccination could begin in just a few weeks. The nightmare was over.
The road to success
Jonas Salk, a medical researcher and virologist who developed the vaccine with his own research team, would rightfully go down in history as the man who eradicated polio. (Today, wild poliovirus circulates in just two countries, Afghanistan and Pakistan – with only 140 cases reported in 2020.) But many people today forget that the widespread vaccination campaign that effectively ended wild polio across the globe would have never been possible without the human clinical trials that preceded it.
As with the COVID-19 vaccine, skepticism and misinformation around the polio vaccine abounded. But even more pervasive than the skepticism was fear. The consequences of polio had arguably never been more visible.
The road to human clinical trials – and the resulting vaccine – was a long one. In 1938, President Franklin Delano Roosevelt launched the National Foundation for Infantile Paralysis in order to raise funding for research and development of a polio vaccine. (Today, we know this organization as the March of Dimes.) A polio survivor himself, Roosevelt elevated awareness and prevention into the national spotlight, even more so than it had been previously. Raising funds for a safe and effective polio vaccine became a cornerstone of his presidency – and the funds raked in by his foundation went primarily to Salk to fund his research.
The Trials Begin
Salk’s vaccine, which included an inactivated (killed) polio virus, was promising – but now the researchers needed test subjects to make global vaccination a possibility. Because the aim of the vaccine was to prevent paralytic polio, researchers decided that they had to test the vaccine in the population that was most vulnerable to paralysis – young children. And, because the rate of paralysis was so low even among children, the team required many children to collect enough data. Francis, who led the trial to evaluate Salk’s vaccine, began the process of recruiting more than one million school-aged children between the ages of six and nine in 272 counties that had the highest incidence of the disease. The participants were nicknamed the “Polio Pioneers.”
Double-blind, placebo-based trials were considered the “gold standard” of epidemiological research back in Francis's day - and they remain the best approach we have today. These rigorous scientific studies are designed with two participant groups in mind. One group, called the test group, receives the experimental treatment (such as a vaccine); the other group, called the control, receives an inactive treatment known as a placebo. The researchers then compare the effects of the active treatment against the effects of the placebo, and every researcher is “blinded” as to which participants receive what treatment. That way, the results aren’t tainted by any possible biases.
But the study was controversial in that only some of the individual field trials at the county and state levels had a placebo group. Researchers described this as a “calculated risk,” meaning that while there were risks involved in giving the vaccine to a large number of children, the bigger risk was the potential paralysis or death that could come with being infected by polio. In all, just 200,000 children across the US received a placebo treatment, while an additional 725,000 children acted as observational controls – in other words, researchers monitored them for signs of infection, but did not give them any treatment.
As with the COVID-19 vaccine, skepticism and misinformation around the polio vaccine abounded. But even more pervasive than the skepticism was fear. President Roosevelt, who had made many public and televised appearances in a wheelchair, served as a perpetual reminder of the consequences of polio, as an infection at age 39 had rendered him permanently unable to walk. The consequences of polio had arguably never been more visible, and parents signed up their children in droves to participate in the study and offer them protection.
The Polio Pioneer Legacy
In a little less than a year, roughly half a million children received a dose of Salk’s polio vaccine. While plenty of children were hesitant to get the shot, many former participants still remember the fear surrounding the disease. One former participant, a Polio Pioneer named Debbie LaCrosse, writes of her experience: “There was no discussion, no listing of pros and cons. No amount of concern over possible side effects or other unknowns associated with a new vaccine could compare to the terrifying threat of polio.” For their participation, each kid received a certificate – and sometimes a pin – with the words “Polio Pioneer” emblazoned across the front.
When Francis announced the results of the trial on April 12, 1955, people did more than just breathe a sigh of relief – they openly celebrated, ringing church bells and flooding into the streets to embrace. Salk, who had become the face of the vaccine at that point, was instantly hailed as a national hero – and teachers around the country had their students to write him ‘thank you’ notes for his years of diligent work.
But while Salk went on to win national acclaim – even accepting the Presidential Medal of Freedom for his work on the polio vaccine in 1977 – his success was due in no small part to the children (and their parents) who took a risk in order to advance medical science. And that risk paid off: By the early 1960s, the yearly cases of polio in the United States had gone down to just 910. Where before the vaccine polio had caused around 15,000 cases of paralysis each year, only ten cases of paralysis were recorded in the entire country throughout the 1970s. And in 1979, the virus that once shuttered entire towns was declared officially eradicated in this country. Thanks to the efforts of these brave pioneers, the nation – along with the majority of the world – remains free of polio even today.