Premalignant Conditions of the Gastrointestinal Tract: A Basis for Selective Screening Programs

Abstract

The results of treating cancer depend greatly on how far the tumour has spread at the time of diagnosis. By the time symptoms appear the tumour has often spread beyond any chance of cure. This is particularly true of gastrointestinal cancers, where surgery remains the only effective treatment. In contrast to the excellent prospects of long term survival for more than 90% of patients with early gastric cancer or cancerous large bowel polyps, extensive series of unselected patients with gastric or colorectal carcinoma have shown 5-year survival rates of 10 and 30% or less (1, 2). Modern diagnostic methods and improved surgical techniques have a limited effect on the survival figures of symptomatic patients. Even the promising advances in cancer immunotherapy, applicable in otherwise hopeless cases, can help few patients because of the complexity and high cost of such treatment (3).