[Treatments of pancreatic cancer from the standpoint of medical oncology].

The early diagnosis of pancreatic cancer is difficult because of the lack of specific early symptoms,and surgery with curative intent can be performed in only 20% of patients. Chemotherapy for unresectable pancreatic cancer has been advancing ever since gemcitabine (GEM) was confirmed to provide a survival advantage in patients with advanced pancreatic cancer. For more than 20 years, the standard treatment for locally advanced diseases has been chemoradiotherapy using 5-FU, but more effective chemotherapy regimens are required. New standard treatments for locally advanced pancreatic cancer, including GEM chemotherapy and chemoradiotherapy using new agents, should be investigated. Several randomized clinical trials comparing GEM-based chemotherapy and GEM alone for the treatment of unresectable pancreatic cancer have been conducted, but a new standard chemotherapy regimen superior to GEM alone has not established. In Japan, phase II studies of S-1 or a combination of GEM and S-1 have produced promising survival rates, and a large phase III study using GEM and S-1 is necessary to establish the standard chemotherapy. Furthermore, second-line chemotherapy regimens for use after GEM chemotherapy should be investigated to improve the survival of patients with advanced pancreatic cancer.