SPEAKER: For this study, we only looked at patients who had surgery and then received chemotherapy and radiation after surgery. Historically, that's been the approach that's been utilized. And our study, looked at patients treated at Mayo between 1987 and 2011. And during that era, the standard approach was for surgery first and then adjuvant treatments after surgery.
But the field of treatment of resectable pancreas cancer has, over the past five years, moved in the direction of administering chemotherapy, with or without radiation, prior to surgery, for a number of reasons. Reasons why we consider that approach is use of radiation and chemotherapy before surgery may make more patients candidates for a complete surgical removal of their tumor.
I feel that, yes, our study shows that adding radiation treatment, in combination with surgery and chemotherapy, reduces the rate of cancer recurrence in the area where the tumor was removed or in the lymph nodes. So I feel that our study fairly conclusively shows that.
The role of radiation therapy in resectable pancreas cancer has been somewhat controversial. There's been some studies that have shown benefit to adding radiation. And there's been some studies that have not shown a benefit. And we know that chemotherapy definitely adds benefit to patients with resected cancer.
And so the point of our study was to look and see, for folks that are getting chemotherapy after resection, does adding radiation treatment provide value for patients. Typically, if we're going to do radiation, we only do one course of treatment. And yes, we're interested in using radiation and chemotherapy prior to surgery more and more frequently for more patients. And typically, if patients get radiation prior to surgery, then we do not consider doing further radiation after the surgery.
Looking at average numbers, it's typically on the order of months. And looking at the percentage of patients who do not have cancer come back, we're talking on the order of 10% to 20%. So we're not talking about huge differences. But when you apply that to 1,000 patients, then we're talking about real numbers of patients who may potentially benefit from the treatments.
There's Commission on Cancer data that look at survival rates for different types of cancer for patients seen and treated at Mayo Clinic versus nationally. And they look at it stage by stage. And for pancreas cancer across all stages, the survival rates for patients seen and treated at Mayo Clinic are statistically higher than the rates seen across the country as the national averages.
And I think that's a reflection of the multidisciplinary approach that we take to pancreas cancer. It's the collaboration of gastroenterologists, surgeons, radiation oncologists, medical oncologists, pathologists, and radiologists all working together to provide the best possible treatment for patients.