By Nancy Lapid
(Reuters) – Patients with colon cancer who still have cancer cells in their blood after surgery may improve their survival odds with daily use of the nonsteroidal anti-inflammatory pill celecoxib, new research suggests.
In a large trial, patients with positive blood tests for circulating tumor DNA (ctDNA) after surgery had worse outcomes in general.
But treatment with celecoxib, sold under the brand name Celebrex by Viatris, significantly prolonged the amount of time they lived without their cancer recurring, according to data presented at the American Society of Clinical Oncology Gastrointestinal Cancers Symposium in San Francisco.
Celecoxib, which belongs to a class of drugs known as COX-2 inhibitors, has been associated with a reduced risk of colorectal polyps and cancer in earlier trials.
In the current study, the 2,526 study participants with cancer confined to the colon and nearby lymph nodes all underwent surgery and received chemotherapy for either three or six months. Patients received either celecoxib or a placebo daily for three years.
While the celecoxib did not appear to prevent cancer recurrence, in a subsequent analysis researchers found that in patients with ctDNA, the drug significantly improved disease-free survival, or the time it takes for the cancer to recur.
They also found that in this subset, recurrence developed in 61% of the celecoxib group and in 77% of the placebo group. After six years of follow-up and after taking patients’ individual risk factors into account, cancer recurrence was 37% less likely with daily celecoxib than with a placebo.
“This is one of the first studies to show that ctDNA status has predictive utility in terms of selecting patients that respond better to a drug,” study leader Dr. Jonathan Nowak of Dana-Farber Cancer Institute and Brigham and Women’s Hospital in Boston said in a statement.
“These findings will help develop a personalized approach to additional therapy for patients with early-stage colon cancer,” Dr. Jeffrey Meyerhardt of Dana-Farber, who also worked on the study, said in a statement.
Off-the-shelf CAR-T cells closer to reality
A less expensive “off-the-shelf” version of revolutionary CAR-T cell blood cancer therapies may someday be possible, a report published on Thursday in Nature suggests.
In CAR-T cell therapy, a patient’s own immune cells are removed and altered so they will attack cancer cells. These T cells are extracted from the blood, genetically modified to fight the individual’s cancer, and then reinfused into the patient, a costly and time consuming process that limits access.
Use of cheaper non-personalized, or allogeneic, CAR-T cells has so far not been feasible because the patient’s immune system rejects them.
To protect allogeneic CAR-T cells from attack by patients’ immune cells, researchers at Memorial Sloan Kettering Cancer Center in New York studied viruses that have evolved and have proteins that help them survive such an assault.
One such protein, or evasin, in the human immunodeficiency virus, called HIV Nef, helps HIV-infected cells evade the immune system.
In experiments in mice, HIV nef added to allogeneic CAR-T cells worked via multiple pathways to help the CAR-T cells evade the immune system and continue to function, according to the report.
“Our study illustrates key principles that inform allogeneic CAR-T cell engineering,” the researchers said.
“Virus-like immune escape can harness multiple mechanisms that act in concert to enhance the therapeutic efficacy of allogeneic CAR T cells.”
Tiny pieces of plastics block brain arteries in mice
Scientists who tracked microplastics moving through the bodies of mice in real time found they eventually become lodged in blood vessels in the brain, according to a report in the journal Science Advances.
It is not clear whether such obstructions occur in people, but in the mice the plastics in brain vessels appeared to affect their movement and behavior, researchers said.
The researchers gave mice water laced with fluorescent spheres of polystyrene, commonly used in manufacturing of appliances, packaging and toys. They used a fluorescence imaging technique to observe the mouse brains through a transparent window surgically implanted into the skull.
Immune cells known as neutrophils and phagocytes ingested the bright plastic specks and traveled through blood vessels to the brain, where they got trapped in tiny blood vessels, the researchers determined.
Mice with plastic clots in the brain moved more slowly, and performed cognitive tasks less efficiently, compared to control mice, the researchers said.
Most of the clots eventually dissolved during the four-week study, and behavior returned to normal.
“Humans and mice have different immune systems, coagulation systems, and cardiovascular and cerebrovascular circulatory systems,” so the findings are not directly applicable to humans, the researchers noted.
Some, however – such as people with a history of heart attack or stroke, and those with obesity and clogged blood vessels – might be more vulnerable to plastic clots in blood vessels, they suggested.
They called for more research into the potential obstructive effects of microplastics in humans.
(Reporting by Nancy Lapid; editing by Bill Berkrot)
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