PATTERNS OF FAILURE IN GROSSLY RESECTED PANCREATIC DUCTAL ADENOCARCINOMA TREATED WITH ADJUVANT IRRADIATION + - 5-FLUOROURACIL/

Purpose: Analyze patterns of failure, survival, and tolerance in patie nts with totally resected ductal adenocarcinoma of the pancreas treate d with adjuvant irradiation alone or combined with chemotherapy. Metho ds and Materials: The records of 29 patients treated with radiotherapy following curative resection of pancreas cancer at the Mayo Clinic we re retrospectively reviewed. Twenty-two (76%) patients underwent a sub total pancreatectomy (Whipple procedure), six (21%) a total pancreatec tomy, and one (3.5%) a distal pancreatectomy. Twenty-six (90%) had les ions located in the head of the pancreas and three (10%) were located either in the body or tail. Twelve (41%) of the tumors were histologic Grade 3, 15 (52%) Grade 2, and two Grade 1. Contiguous invasion of ad jacent tissues or organs was found in fifteen patients (52%) and seven teen (59%) had lymph node involvement. Greater than 75% of patients re ceived more than 45 Gy, with a median dose of 54 Gy, and twenty-seven (93%) patients received concomitant 5-fluorouracil chemotherapy. Resul ts: The median survival was 22.8 months and the 2-year survival 48%. W hen survival was compared with that achieved with surgery alone in our institution, data suggested a doubling in both median and long-term s urvival with the addition of adjuvant treatment. Eighty-three percent of patients experienced tumor relapse with seventeen of 29 (59%) devel oping either liver metastases or peritoneal spread. In three patients, tumors recurred locally; one of one with microscopic residual disease after resection and two of 28 (7%) with negative margins (one of the two was treated with inadequate radiation portals). Patients tolerated adjuvant treatment with minimal acute toxicity consisting mostly of v omiting or nausea which, were controlled with medication in all patien ts. Chronic toxicity was acceptable; while 5 of 29 (17%) developed som e form of possible treatment related complication, only one patient (3 .5%) developed a small bowel obstruction. Conclusion: These results co rroborate data in previous studies which have shown a survival benefit when adjuvant irradiation plus 5-fluorouracil is used in patients wit h completely resected ductal adenocarcinoma of the pancreas. The patte rns of failure indicate that post-operative adjuvant treatment can eff ectively control disease locally but that future survival improvements will be achieved only by reducing the incidence of liver and peritone al metastases.