Optimal adjuvant therapy for resected pancreatic cancer: chemotherapy or chemoradiotherapy?

Despite recent research and advances in the understanding of the molecular and genetic basis of pancreatic cancer, the poor outcomes experienced by pancreatic cancer patients have changed little during the past 30 years. Adenocarcinoma of the pancreas is the fourth leading cause of cancer-related death in the United States, with only a small fraction of patients achieving long-term survival. According to data from the American Cancer Society, 5-year survival for pancreatic cancer patients is 5%; an estimated 33,730 newly diagnosed cases of pancreatic cancer will be nearly equaled by an estimated 32,300 pancreatic cancer deaths in the United States. This underscores the continued need to develop novel multimodality treatment approaches for this disease. Surgery has proved vital to a curative-intent treatment approach for these patients. However, only 10% to 20% of newly diagnosed patients present with potentially resectable nonmetastatic disease. In light of the minority of patients with resectable disease, there has been considerable debate over the potential advantages of adjuvant chemotherapy and radiotherapy. In recent decades, cooperative groups both in the United States and abroad have conducted randomized clinical trials seeking to define the potential benefit of adjuvant chemotherapy or adjuvant chemoradiotherapy vs. surgery alone for patients with resectable disease. Unfortunately, the results of these trials have been conflicting and no definitive consensus has yet been reached regarding optimal adjuvant therapy. This article reviews cooperative group data pertinent to this debate. It is suggested that (1) patients do benefit from adjuvant therapy, and (2) optimal adjuvant therapy should include gemcitabine-based chemoradiotherapy for select patient subgroups.