Precision Medicine Makes Cancer Treatment Options Easier to Determine

Researchers seek to improve care for rare, difficult-to-treat, and aggressive cancers.

For pediatric patients with cancer, hope may be on the horizon as precision medicine allows physicians to better determine the optimal treatment option.

A new study found that using information from a patient’s entire genome helped suggest personalized treatment options for nearly half of children with cancer, and led to specific treatment changes in a quarter of these patients.

The study is based on a program implemented at CS Mott Children’s Hospital in 2012 called Peds-MiOncoSeq, which includes sequencing the tumor’s DNA and RNA, as well as normal DNA from children and young adults with cancer that has relapsed or that is rare.

“We found that for some children with rare, difficult-to-treat and aggressive cancers, this technology can dramatically change the course of their treatment,” said lead author Rajen Mody, MD, MS, pediatric oncologist at CS Mott Children’s Hospital. We have made significant strides in cancer treatment but for some kids, especially those with metastatic or relapsed disease, even the most advanced, proved therapies have not been able to improve their outcome. Our approach in precision oncology showed its greatest promise in these difficult to treat patients — 80% of our study patients had relapsed or refractory disease, and those are the ones who benefited most from our study.”

Of the patients involved in the study, 46% had actionable findings, including a genetic anomaly that is the target of an approved or experimental drug; a change in diagnosis; or genetic counseling for inherited cancer risk that could affect the patient or the whole family.

Furthermore, 25% of patients moved on to receive a study-recommended novel therapy, and 10% of these patients achieved remission that lasted 6 months or longer.

“We were excited to see an actionable finding in such a substantial percentage of patients, and we think it could potentially be higher over time. These are patients who had exhausted all proven therapeutic options or who had an extremely rare diagnosis. If we can find a clinically actionable event and have a chance to act upon it, we show in this study that it can have a big impact on that patient,” said senior study author Arul Chinnaiyan, MD, PhD, director of the Michigan Center for Translational Pathology.

Additionally, the research found that 10% of patients had an inherited cancer risk that could pose a threat to other family members. These patients were offered genetic counseling. Four of the nine families had no notable family history to suggest an inherited risk, and they would not otherwise have been referred for genetic counseling.

Genetic sequencing is a complex process that involves looking at all of the DNA and RNA that are part of a patient’s genes. Scientists screen each piece of data for anomalies that may prove to be targets for existing approved or experimental therapies.

“Each child is different when it comes to predicting how they will respond to different cancer treatments,” Mody said. “This individualized genetic information helps us better predict what genetic change is driving a particular child’s tumor, what’s causing the resistance to the treatment and how to predict response to certain treatments. This knowledge can help us match each patient with the specific therapy most likely to benefit him or her.”

A precision medicine tumor board reviewed the sequencing results, which included pediatric and adult oncologists, genetics specialists, pathologists, bioinformatics specialists, and genetic counselors. The group discussed the results and made decisions about pursuing treatment options based on the genomic findings.

Cost of the sequencing was approximately $6,000 per patient and was covered under research protocol. Patients did not pay out of pocket for sequencing. As technology improves and competition increases, scientists hope the high pricing will drop. Improvements in technology will help scientists receive results faster, as the current method takes about 7 to 8 weeks to receive results.

“These are early days and the full promise of precision medicine is yet to be fully realized,” Mody said. “We need better targeted therapies designed for children, and turnaround time for sequencing needs to be less than two weeks for it to be a regular part of a patient’s treatment plan.”

With time, scientists hope the genetic sequencing will become routine practice for pediatric patients with cancer. The initial findings have paved the way to expand the program into a more comprehensive pediatric precision oncology program that researchers expect to launch in 2016, which will include offering sequencing to pediatric cancer patients diagnosed at other hospitals.

“The earlier we can carry out the sequencing the better chance of identifying the right therapy before they develop resistance to therapies we could predict wouldn’t work. We hope to make it commonplace for patients to have a molecular blueprint of their tumor to guide treatment choices,” Chinnaiyan said.