Since 1981, the Japan Pancreas Society (JPS) and National Cancer Center have jointly maintained the nationwide pancreatic cancer registry. Currently, there are 28,655 cases registered, with 12,608 cases of histologically confirmed invasive pancreatic cancer. Since the last revision of the International Union Against Cancer (UICC) classification in 2002, the survival analysis of the patients registered from 2001 to 2004 became possible for the first time. Using this detailed database, the rational of R0 resection was investigated. From 2001 to 2004, 2617 cases of histologically confirmed invasive ductal carcinoma of the pancreas were registered. According to the UICC classification, R0 resection becomes problematic mostly in UICC stage IIa and IIb. Of 1039 patients who underwent pancreatectomy for the tumor in the head of the pancreas, 160 had UICC stage IIa disease, and 468 had UICC stage IIb disease. The relationship between the survival and the extent of disease, together with portal vein (PV) resection, plexus (PL) resection, were analyzed. PV, retroperitoneal, and PL infiltration had a significant impact on the accomplishment of R0 resection in univariate and multivariate analyses. There was no advantage of PV resection for both PV (−) and PV (+) disease among UICC stage IIa or IIb patients, suggesting no benefit of prophylactic PV resection. Similarly, survival depends on PL invasion but not on combined resection of PL. There was no survival benefit associated with the extent of lymph node dissection. Survival among patients treated in the 2000s, after the introduction of gemcitabine in Japan, is significantly better than that of patients treated in the 1980s and 1990s. Although survival after pancreatectomy depends on the extent of disease rather than the surgical procedures, the chronologic improvement in survival indicates that chemotherapy had a significant impact on survival; development of new treatment modalities is awaited.