In the war against cancer, doctors often have to treat patients who face a high mutational burden, such as in cases of metastatic breast cancer. To develop and test new methods of treatment, researchers are making use of next generation sequencing or NGS.
A recent example is the TAPUR study (short for Targeted Agent and Profiling Utilization Registry) from ASCO that scientists reported on in the Journal of Clinical Oncology, according to Michigan Medicine.
Read on for context about how next generation sequencing (NGS) was used in this recent breast cancer study.
About Next Generation Sequencing
Biotechnology and the rapid growth in computer systems paved the way for more efficient tools to study what’s happening to people at the genetic level.
Next generation sequencing uses high-speed computer systems with massive amounts of storage capacity to quickly run through the enormous quantities of genetic information obtained from a patient’s sample. This is an approach that ordinary human beings cannot do by themselves rapidly, but it’s well-suited to machines automated with software in the lab.
With parallel computing, the scientists can compare known examples of genetic sequences for diseases such as cancer against samples obtained from patients.
How Was Next Generation Sequencing Key to This Breast Cancer Study?
For the TAPUR study, the researchers had a goal to use next generation sequencing data to learn whether some cancer drugs that have already been approved for use against one kind of cancer could also be useful in treating patients with a different kind of cancer, per Michigan Medicine.
The drugs might be useful in these other types of cancer because of certain changes in the DNA in their tumors. In the TAPUR study, scientists recruited 28 women who had advanced breast cancer to participate in trials at multiple locations between 2016 and 2018.
Every one of these patients had been diagnosed with advanced breast cancer that had a high level of mutations in the tumors. This is what’s known as “high tumor mutational burden.” To qualify to be enrolled in the study, the patients had to have already undergone multiple rounds of conventional cancer treatment.
The researchers were studying the use of an immunotherapy agent called pembrolizumab, and determined that it can offer some clinical benefit to patients with metastatic breast tumors that have a large amount of mutations, and in cases where standard treatment did not stop the growth of these tumors.
Results of the Phase 2 study indicate that approximately one-third of those patients participating in the trial did see their tumors controlled with pembrolizumab. A fraction of these patients experienced benefits that lasted at least a year, according to the medical journal report.
Using Next Generation Sequencing for All Patients With Advanced Tumors?
The drug pembrolizumab is a special kind of immunotherapy called a checkpoint inhibitor, which blocks protein PD-1 binding. As a result, the patient’s immune system can work more effectively against breast cancer. So ongoing studies of patients with cancer that has a high mutational burden could help more women recover from breast cancer, thanks to next generation sequencing to identify the genetic characteristics quickly and accurately.
But there should be benefits to other patients, too. The study’s principal investigator Ajjai Alva, MBBS, who is an oncologist at Michigan Medicine said that while immunotherapy won’t necessarily work with all cancer patients, but when it does work, it is quite effective. Looking forward, Alva indicates that there is evidence that next generation sequencing should be part of the standard of care for every patient who happens to have an advanced form of cancer.