Pancreatic cancer has long been a death sentence for most patients, with survival odds low even for people who undergo harsh treatment regimens of chemotherapy, radiation, and surgery to remove tumors.
But the results of a small study published May 10 in the journal nature It suggests that messenger RNA (mRNA) vaccines — the same technology used to develop a preventative treatment for COVID-19 — may also prevent the return of these hard-to-treat tumors.
For the study, the scientists analyzed tumor tissue samples from 16 people who had surgery for pancreatic cancer. Next, the researchers gave each patient an mRNA vaccine specific for their tumor type.
Half of the patients showed a strong immune response to vaccination, and the tumors did not reappear in these individuals after a median follow-up period of 18 months. By contrast, tumors returned after a median follow-up period of about 13 months among patients who did not respond to the vaccine.
“These exciting results indicate that we may one day be able to use vaccines as a treatment against pancreatic cancer,” said the study’s senior author, Vinod Balachandran, of Memorial Sloan Kettering Cancer Center in New York City, in a statement. “The evidence supports our strategy to tailor each vaccine to each patient’s tumor.”
Larger trials are needed to adjust and confirm the results
In addition to its small size, another limitation of the study is that all participants were white, and these results likely would not be seen with individuals of different racial or ethnic backgrounds.
A larger clinical trial involving more patients is expected to begin recruiting participants this summer, according to the release.
If this larger trial gets results confirming the initial findings of an mRNA vaccine for pancreatic cancer, it will be a major advance in treatment, because there are currently few immunotherapies that can delay or prevent tumor recurrence in people undergoing pancreatic cancer surgery, Anerban says. Maitra, MBBS, professor and director of the Pancreas Research Center at the University of Texas MD Anderson Cancer Center in Houston.
Moreover, while this trial was geared toward preventing a recurrence in patients already with cancer, the mRNA vaccine could also be used in a future trial to completely prevent pancreatic cancer from occurring in the first place in high-risk patients — a holy grail, says Dr. Mitra, who has not participates in the new study, “grail as far as I’m concerned.”
The study offers hope for people diagnosed with pancreatic cancer
In the United States, pancreatic cancer is the fourth leading cause of cancer death in both men and women. The five-year survival rate for these patients is only 12 percent.
Four out of five patients are diagnosed with pancreatic cancer when the tumors are so advanced that surgery isn’t an option, Mitra says. The new vaccine study focused on the minority of patients who undergo surgery and have the best odds of survival, Mitra says.
“If larger trials show that the vaccine can effectively delay recurrence and allow patients to live longer, that will be a real demonstration of the power of this vaccine strategy,” says Maitra. “However, we first have to wait for those larger trials to happen.”