Two-stage radical gastrectomy for perforated gastric cancer - Lehnert, Thomas; Buhl, Klaus; Dueck, Margret; Hinz, Ulf; Herfarth, Christian (External validation of disease-free survival at 2 or 3 years as a surrogate and new primary endpoint for patients undergoing radical cystectomy for urothelial carcinoma of the bladder, 2000)