SOME IMMUNOLOGICAL ASPECTS OF GASTHOINTESTINAL TRACT MALIGNANCIES: AN UP DATE

Abstract

A dynamic interaction exists between growing cancer cells and their environment. This balance may be influenced by changein either the tumour or the host. In the tumour a rapid cell doubling time, invasiveness and a propensity to metastases are a ll associated with poor prognosis. In the host genetic factors, the endocrine milieu, blood coagulation and nutri tional state, as well as i mmunological reactions may influence tumou r development and growth (Baba, 1997).

Also, studies in patients treated with long-term immunosupressive therapy have revealed an increased incidence of neoplasm just as individuals with primary immunodeficiency states have an incidence of neoplasia roughly 10.000 times that of the general age matched popul ation (Rey eta/., 1998).

In addition, it has been suggested that the peaks of neoplasia which occur in infancy and in old age,can in part be accounted for by diminished immunological surveillance at the extremes of life (Polyoak eta/., 1999).

In the gastrointestinal tract the problem appears particularly provocative with malignancy appearing in several disorders whi ch show gross immunological changes. Such