3 factors may extend survival in advanced pancreatic cancer

A new Mayo Clinic study suggests that some patients with pancreatic cancer could increase survival with adjustments to their chemotherapy regimen before surgery.

Historically, most patients with pancreatic cancer whose tumors grow outside the pancreas to encompass veins and arteries have been told the cancer is inoperable and they should prepare for an average survival time of 12 to 18 months.

However, a newly published Mayo Clinic study finds that a presurgery treatment plan focused on three chemotherapy-related factors can extend life years beyond that average. The findings were published in the Annals of Surgery, the journal of the American Surgical Association and the European Surgical Association.

The study followed 194 Mayo Clinic patients who received chemotherapy followed by radiation and surgery. An average survival time of 58.8 months, or just under five years, was achieved.

The researchers found that patients who had three factors experienced significantly longer survival times than those who didn't have these factors:

• Extended chemotherapy before surgery; the more cycles they had, the longer the survival
• A CA 19-9 tumor marker that fell to a normal level after chemotherapy
• A tumor that, when surgically removed, was found to be completely or mostly dead due to chemotherapy

The lead author of the published pancreatic cancer study, Mark J. Truty, M.D., M.S., an oncologic surgeon at Mayo Clinic in Rochester, Minnesota, estimates that roughly half of his patients with vein and artery involvement came to him after being told elsewhere that their cancer was inoperable. He hopes the study findings convince physicians that for many such patients, long-term survival is possible if patients receive appropriate treatment before surgery.

"We now have more-advanced surgical techniques and more-effective chemotherapy and radiation therapy. We can take all of these advances and put them together to get the outcomes we are looking for," Dr. Truty said. "The goal is to extend patients' lives and maintain or improve their quality of life."

About 55,000 people in the U.S. are diagnosed with pancreatic cancer each year. In about a third, the tumor has not spread to other organs but has grown outside the pancreas to wrap around veins and arteries — these tumors are typically considered borderline resectable or locally advanced. The conventional wisdom has been that surgery gives patients with pancreatic cancer the only chance at long-term survival, but that these tumors are inoperable because of a high risk that cancer will be left behind and their prognosis for survival will be poor.

The Mayo Clinic study refutes that conventional wisdom.

The research team followed 194 of these patients treated at Mayo Clinic over seven years. All received personalized chemotherapy followed by radiation and tumor-removing surgery. For most patients, the surgery included removing and reconstructing veins or arteries, or both, ensnared by pancreatic tumors. Crucial to their care before surgery was finding the right chemotherapy and continuing it until the CA 19-9 tumor marker was normal and positron emission tomography, a form of advanced imaging known as a PET scan, showed the tumor was dead, Dr. Truty said.

The more of those three factors patients had, the better they did. Because the three factors were all related to chemotherapy and the response to it, it may be possible to help many more patients achieve those factors by adjusting their chemotherapy before surgery, Dr. Truty said.

Twenty-nine percent of the patients had all three factors identified in the study. Their median survival time hasn't yet been calculated because more than half are still alive. An additional 29% had two factors, and their median survival was 58.8 months.

Thirty-one percent had one factor and a median survival of 29.7 months. Eleven percent had none of the factors, and their median survival was 18.5 months.

"The bottom line is patients with these advanced cancers can do very well if they're treated in the right manner prior to the operation," Dr. Truty said. "Our data shows there's no difference in survival long term if you had a vein or artery involved or not. It's those three factors related to how chemotherapy was administered, and if it was effective, only then moving on to radiation and surgery."

However, just as important as identifying who is a good candidate for surgery is pinpointing who is a poor candidate, Dr. Truty said. For patients whose tumor has grown outside the pancreas, the operation is more complex than is surgery in patients whose cancer has not spread beyond the pancreas, and the risks must be weighed against the predicted benefit. Given the magnitude of the surgery, it is only performed at a few centers in the U.S., including at Mayo Clinic.

Related

• Mark Truty, M.D., M.S.
• Factors Predicting Response, Perioperative Outcomes, and Survival Following Total Neoadjuvant Therapy for Borderline/Locally Advanced Pancreatic Cancer
• Pancreatic cancer
• Positron emission tomography

This article was originally published in Forefront, Mayo Clinic Cancer Center's online magazine, which ceased publication in December 2020.