(CBS News) -- When a routine scan led to Barbara Brigham's pancreatic cancer diagnosis in 2020, all she could think about was how she wanted more time. Her husband had just passed away. She loved her local library job. Her three children were still growing their own families.

She turned to her care team at Memorial Sloan Kettering Cancer Center to learn about her options. Brigham had first come to the cancer center when she was diagnosed with a small, non-cancerous cyst on her pancreas. Every year, she had a scan to make sure there were no new cysts. It was that annual scan that found the early-stage pancreatic cancer.

Brigham and her youngest son went to Sloan-Kettering the next day to meet with Dr. Vinod Balachandran, a surgical oncologist who specializes in pancreatic cancer. While laying out her options to fight the cancer, he mentioned that he was running a clinical trial that he believed she would be the "perfect candidate" for.

The trial would combine standard surgery and chemotherapy treatments -- which are the standard of care for pancreatic cancer -- with a customized mRNA vaccine. Each vaccine would be designed based on the patient's individual tumor. The idea was that the vaccines could hopefully help the body's immune system attack the cancer, Balachandran told CBS News.

"I looked at my son, and my son said, 'Absolutely.' So we decided to do that," Brigham said. "The prognosis was not good when I was diagnosed. You know you're going to have a limited amount of time. I just wanted to extend that time."

The inspiration for the clinical trial came from the small handful of long-term pancreatic survivors, Balachandran said. Only about 10% of people diagnosed with pancreatic cancer survive for more than five years.

About a decade ago, Balachandran and other researchers turned their attention to these "long-term" survivors. Multiple studies found that the long-term survivors' immune systems generated "spontaneous immune response" to the cancer, meaning the immune system could recognize that the cancer was a threat and react accordingly. Typically, it's "challenging" to teach the immune system to recognize cancer, said Balachandran, because "the immune system is hardwired not to recognize our own body."