A scientist works on a blood test in the Ajay Goel Lab, one of many labs that are developing blood tests to screen for different types of cancer.
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.”
Paul Alexander spent more than 70 years confined to an iron lung after a polio infection left him paralyzed at age 6. Here, Alexander uses a mirror attached to the top of his iron lung to view his surroundings.
Paul Alexander was one of several thousand who were infected and paralyzed by polio in 1952. That year, a polio epidemic swept the United States, forcing businesses to close and polio wards in hospitals all over the country to fill up with sick children. When Paul caught polio in the summer of 1952, doctors urged his parents to let him rest and recover at home, since the hospital in his home suburb of Dallas, Texas was already overrun with polio patients.
Paul rested in bed for a few days with aching limbs and a fever. But his condition quickly got worse. Within a week, Paul could no longer speak or swallow, and his parents rushed him to the local hospital where the doctors performed an emergency procedure to help him breathe. Paul woke from the surgery three days later, and found himself unable to move and lying inside an iron lung in the polio ward, surrounded by rows of other paralyzed children.
Hospitals were commonly filled with polio patients who had been paralyzed by the virus before a vaccine became widely available in 1955. Associated Press
But against all odds, Paul lived. And with help from a physical therapist, Paul was able to thrive—sometimes for small periods outside the iron lung.
The way Paul did this was to practice glossopharyngeal breathing (or as Paul called it, “frog breathing”), where he would trap air in his mouth and force it down his throat and into his lungs by flattening his tongue. This breathing technique, taught to him by his physical therapist, would allow Paul to leave the iron lung for increasing periods of time.
With help from his iron lung (and for small periods of time without it), Paul managed to live a full, happy, and sometimes record-breaking life. At 21, Paul became the first person in Dallas, Texas to graduate high school without attending class in person, owing his success to memorization rather than taking notes. After high school, Paul received a scholarship to Southern Methodist University and pursued his dream of becoming a trial lawyer and successfully represented clients in court.
Paul Alexander, pictured here in his early 20s, mastered a type of breathing technique that allowed him to spend short amounts of time outside his iron lung. Paul Alexander
Throughout his long life, Paul was also able to fly on a plane, visit the beach, adopt a dog, fall in love, and write a memoir using a plastic stick to tap out a draft on a keyboard. In recent years, Paul joined TikTok and became a viral sensation with more than 330,000 followers. In one of his first videos, Paul advocated for vaccination and warned against another polio epidemic.
Paul was reportedly hospitalized with COVID-19 at the end of February and died on March 11th, 2024. He currently holds the Guiness World Record for longest survival inside an iron lung—71 years.
Polio thankfully no longer circulates in the United States, or in most of the world, thanks to vaccines. But Paul continues to serve as a reminder of the importance of vaccination—and the power of the human spirit.
““I’ve got some big dreams. I’m not going to accept from anybody their limitations,” he said in a 2022 interview with CNN. “My life is incredible.”
