Researchers at the University’s Michigan Center for Translational Pathology announced this month a new breakthrough in pediatric cancer treatment — the use of genetic sequencing.
Using a practice called precision oncology, a team of University researchers conducted a study that used genetic sequencing to tailor diagnoses and develop new drug treatment for cancer patients for whom standard treatments were no longer effective. In some cases, researchers were able to recommend early counseling for family members based on the results.
Genetic sequencing is the practice of determing the unique composition of an individual DNA strand — a process that can provide researchers and doctors with important information about a patient, the disease they have and the best approach to treating it.
The study’s lead author, Rajen Mody, a pediatric oncologist at C.S. Mott Children’s Hospital and clinical director of pediatric hematology and oncology, said the study was the first of its kind in the field of pediatric oncology.
The ongoing study, which began in 2012, is focused on 142 children and young adults who have a cancer diagnosis. Eighty percent of patients in the group had exhausted the standard treatment options available. For each patient, the sequencing produced more than two terabytes of data — a significant amount of information. The tests currently take more than six weeks to complete, significantly faster than previous gene sequencing mechanisms which often took years. Mody said researchers hope to ultimately cut this time down to three weeks.
The study used new technology called Next-Generation DNA Sequencing to sequence a patient’s tumor’s DNA and RNA, as well as their normal genome. The genome is the complete set of genetic information inside a cell. Through comparing the tumor’s genome and the normal genome, researchers were then able to identify the source of the cancer and any potential difficulties the patient could facing during treatment.
Out of the entire study, the doctors found that 46 percent of patients had “actionable findings,” from the sequencing. However, they were only able to take action with 25 percent of the total number of patients.
“Just because you have this information where you know what you can do does not mean you can do something,” Mody said. “Sometimes there are no drugs available, the patient is too sick, there are no clinical trials available, there are no small tablets available for children, etcetera.”
John Maris, a pediatric oncologist at the Children’s Hospital of Philadelphia who published an editorial alongside the study, told HealthDay that an additional challenge for treatment was that drug companies are also reluctant to study children.
“There’s a fear of the drugs being more toxic in children,” Maris told HealthDay.
Of the 25 percent of patients treated, doctors were able to change an original diagnosis, begin early treatment on family members for prevention or change treatment strategies entirely.
According to Mody, in at least 10 percent of the patients, the team was able to produce six months of remission or symptom relief.
“I think one of the things that people lose sight of is that 10 percent either sounds large or small, depending on what you know about the patients,” he said. “These are patients for whom there is nothing else out there. These people have tried everything that they’ve wanted to try, so these are the worst of the worst cases.”
Moving forward, he said, the biggest challenges include decreasing the time it takes to begin treatment, producing more drugs that are available for young children and increasing the availability of clinical drug trials.
“This is a seminal and landmark study, but there’s a lot more work to be done,” Mody said.