Oesophageal carcinoma: cytopathology and nutritional aspects in aetiology.

This work includes results from studies on oesophageal cytopathology, dietary studies and the correlation of oesophageal cytological abnormalities and micronutrient blood levels in populations at risk for oesophageal carcinoma (OC) in remote rural areas of Southern Africa. The incidence of malignant lesions was 1.6 - 2.8%, and moderate to severe dysplastic lesions 0.5 - 1.8% in subjects aged over 35 years. Subjects 25-34 years of age showed malignant and dysplastic lesions in 0.8 and 1.3% respectively. Subjects younger than 24 years of age showed mild cytological lesions only. Early stages of OC were diagnosed in 8 patients. Three of them successfully underwent surgical intervention and are free from recurrence or metastases over a 3 year follow-up period. The incidence of mild oesophageal cytological lesions was inversely related to the frequency of the intake of green vegetables, fruit and animal proteins, and directly related to alcohol intake or tobacco smoking. A lower plasma concentration of vitamins A, E, B12 and folic acid was detected in individuals with cytological abnormalities. Of the mineral elements, only selenium, but not zinc, copper or magnesium was significantly related to the risk for OC on a regional or individual basis. An exceptionally low whole blood selenium level (58-72 ng/ml) and a relationship between its concentration and degree of cytological abnormalities were found.