Researchers in Dallas are developing a new technology that they hope will literally shed light on a problem that has frustrated cancer surgeons worldwide.
The removal of cancerous tumors through surgery is an often life-saving treatment option — but it’s not an exact science.
“It’s always a balance between taking out too much or too little tissue,” explained Dr. Baran Sumer, a surgeon focused on cancers of the head and neck from the University of Texas Southwestern Medical Center.
Oncologists want to remove as much cancerous tissue from the body as possible, so the disease does not continue to grow or spread. But removing too much can result in deformations and other complications for patients.
Sumer and a team of researchers from the Simmons Comprehensive Cancer Center developed a technology called a pH Nanosensor, an injection that seeks out cancerous areas in the body and causes them to light up.
The goal is to help surgeons more precisely determine how much to cut and possibly reduce the need for extra procedures.
In findings published recently in Nature Biomedical Engineering, the injection had positive results in a study of mice with tumors of the head, neck and others.
While promising, it’s important to note that the research is very preliminary. It’s too early to tell whether it will have the same effect in humans.
“That’s going to be the big question mark,” said Dr. Otis Brawley, chief medical officer for the American Cancer Society. “There are many reasons on a(n) immunologic and cellular level why it might work in a mouse, but not in a human.”
Still, local researchers may be on the forefront of understanding the technology’s potential.
In 2015, they were awarded a grant from the National Cancer Institute totaling more than $1.8 million for a five-year period. UTSW has also received two research grants from the Cancer Prevention Research Institute of Texas. Dallas-based OncoNano Medicine, a UTSW spinoff company that wants to commercialize the technology, has received $6 million in CPRIT funding.
“They have a pathway toward realizing the potential,” said CPRIT’s chief scientific officer, Dr. James Willson. The researchers have focused on head-and-neck and some other cancers, but the problem of precision is faced by surgeons for many different types of cancers, he said.
Here’s how it works. Cancer tumors have a pH that is slightly more acidic than normal tissue. “It’s one of the few distinguishing characteristics that cuts across all cancer types,” explained Jimming Gao, a bioengineer working on the design aspect of the probe.
The fluorescent sensor targets the different pH signals, thus making them glow so they are easier to distinguish from normal tissue.
The recent study found that surgeons were able to excise more of the cancerous tissue in 18 rats after it had been illuminated. The long-term survival of the mice was also improved. While many questions remain, UT Southwestern is among a handful of entities turning to technologies that can light up cancer cells.
For example, Seattle Children’s Hospital is researching a “molecular flashlight” for brain cells. Researchers from North Carolina and Massachusetts developed a probe called LUM015 that causes concentrations of cancerous tissues to become fluorescent.
The Dallas researchers are seeking approval from the Food and Drug Administration to begin early-stage clinical trials to test their injection in humans in 2017 and identify potential side effects.
Future studies will then need to evaluate whether attempts to spot and remove all areas of disease is effective with metastasized cancers, added Brawley. “Surgical cherry-picking,” he says, has not helped patients in the past, though he encourages additional research.
Finding cancers cells that have metastasized and spread throughout the body has been one of the biggest challenges for cancer detection and diagnosis.
“Drugs frequently don’t go to every place the tumor exists. It hits about 95 percent … and that’s not enough,” Brawley said.