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.
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.”
Amber Freed and Maxwell near their home in Denver, Colorado.
Getting the diagnosis took months of painful, invasive procedures, as well as fighting with the health insurance to get the genetic testing approved. Finally, in June 2018, doctors at the Children's Hospital Colorado gave the Freeds their son's diagnosis—a genetic mutation so rare it didn't even have a name, just a bunch of letters jammed together into a word SLC6A1—same as the name of the mutated gene. The mutation, with only 40 cases known worldwide at the time, caused developmental disabilities, movement and speech disorders, and a debilitating form of epilepsy.
The doctors didn't know much about the disorder, but they said that Maxwell would also regress in his development when he turned three or four. They couldn't tell how long he would live. "Hopefully you would become an expert and educate us about it," they said, as they gave Freed a five-page paper on the SLC6A1 and told her to start calling scientists if she wanted to help her son in any way. When she Googled the name, nothing came up. She felt horrified. "Our disease was too rare to care."
Freed's husband, a 6'2'' college football player broke down in sobs and she realized that if anything could be done to help Maxwell, she'd have be the one to do it. "I understood that I had to fight like a mother," she says. "And a determined mother can do a lot of things."
The Freed family.
Courtesy Amber Freed
She quit her job as an equity analyst the day of the diagnosis and became a full-time SLC6A1 citizen scientist looking for researchers studying mutations of this gene. In the wee hours of the morning, she called scientists in Europe. As the day progressed, she called researchers on the East Coast, followed by the West in the afternoon. In the evening, she switched to Asia and Australia. She asked them the same question. "Can you help explain my gene and how do we fix it?"
Scientists need money to do research, so Freed launched Milestones for Maxwell fundraising campaign, and a SLC6A1 Connect patient advocacy nonprofit, dedicated to improving the lives of children and families battling this rare condition. And then it became clear that the mutation wasn't as rare as it seemed. As other parents began to discover her nonprofit, the number of known cases rose from 40 to 100, and later to 400, Freed says. "The disease is only rare until it messes with the wrong mother."
It took one mother to find another to start looking into what's happening inside Maxwell's brain. Freed came across Jeanne Paz, a Gladstone Institutes researcher who studies epilepsy with particular interest in absence or silent seizures—those that don't manifest by convulsions, but rather make patients absently stare into space—and that's one type of seizures Maxwell has. "It's like a brief period of silence in the brain during which the person doesn't pay attention to what's happening, and as soon as they come out of the seizure they are back to life," Paz explains. "It's like a pause button on consciousness." She was working to understand the underlying biology.
To understand how seizures begin, spread and stop, Paz uses optogenetics in mice. From words "genetic" and "optikós," which means visible in Greek, the optogenetics technique involves two steps. First, scientists introduce a light-sensitive gene into a specific brain cell type—for example into excitatory neurons that release glutamate, a neurotransmitter, which activates other cells in the brain. Then they implant a very thin optical fiber into the brain area where they forged these light-sensitive neurons. As they shine the light through the optical fiber, researchers can make excitatory neurons to release glutamate—or instead tell them to stop being active and "shut up". The ability to control what these neurons of interest do, quite literally sheds light onto where seizures start, how they propagate and what cells are involved in stopping them.
"Let's say a seizure started and we shine the light that reduces the activity of specific neurons," Paz explains. "If that stops the seizure, we know that activating those cells was necessary to maintain the seizure." Likewise, shutting down their activity will make the seizure stop.
Freed reached out to Paz in 2019 and the two women had an instant connection. They were both passionate about brain and seizures research, even if for different reasons. Freed asked Paz if she would study her son's seizures and Paz agreed.
To do that, Paz needed mice that carried the SLC6A1 mutation, so Freed found a company in China that created them to specs. The company replaced a mouse SLC6A1 gene with a human mutated one and shipped them over to Paz's lab. "We call them Maxwell mice," Paz says, "and we are now implanting electrodes into them to see which brain regions generate seizures." That would help them understand what goes wrong and what brain cells are malfunctioning in the SLC6A1 mice—and help scientists better understand what might cause seizures in children.
Bred to carry SLC6A1 mutation, these "Maxwell mice" will help better understand this debilitating genetic disease. (These mice are from Vanderbilt University, where researchers are also studying SLC6A1.)
Courtesy Amber Freed
This information—along with other research Amber is funding in other institutions—will inform the development of a novel genetic treatment, in which scientists would deploy a harmless virus to deliver a healthy, working copy of the SLC6A1 gene into the mice brains. They would likely deliver the therapeutic via a spinal tap infusion, and if it works and doesn't produce side effects in mice, the human trials will follow.
In the meantime, Freed is raising money to fund other research of various stop-gap measures. On April 22, 2021, she updated her Milestone for Maxwell page with a post that her nonprofit is funding yet another effort. It is a trial at Weill Cornell Medicine in New York City, in which doctors will use an already FDA-approved drug, which was recently repurposed for the SLC6A1 condition to treat epilepsy in these children. "It will buy us time," Freed says—while the gene therapy effort progresses.
Freed is determined to beat SLC6A1 before it beats down her family. She hopes to put an end to this disease—and similar genetic diseases—once and for all. Her goal is not only to have scientists create a remedy, but also to add the mutation to a newborn screening panel. That way, children born with this condition in the future would receive gene therapy before they even leave the hospital.
"I don't want there to be another Maxwell Freed," she says, "and that's why I am fighting like a mother." The gene therapy trial still might be a few years away, but the Weill Cornell one aims to launch very soon—possibly around Mother's Day. This is yet another milestone for Maxwell, another baby step forward—and the best gift a mother can get.