Abstract
A thorough understanding of the naturally occurring events in the immune system in response to carcinogenesis will facilitate the development of strategies for the immunoprevention of cancer. The adenoma-carcinoma sequence in the human colon is a well-established clinical example of multi-step carcinogenesis and can be used for immunological studies. Based on previous observations that both apoptosis and the expression of Fas (Apo-1, CD95) are altered during carcinogenesis in the human colon, we asked the question whether serum titers of autoantibodies against Fas show any modification during the adenoma-carcinoma sequence. Healthy controls (38), patients with colorectal adenomas (38) and patients with colorectal adenocarcinomas (21) were investigated. Anti-Fas antibody titers were found to be significantly higher in patients with colorectal adenomas than in healthy controls and higher still in patients with colorectal adenocarcinomas. This increase in anti-Fas autoantibody titers during carcinogenesis might reflect the activation of natural defense mechanisms by the immune system.