KAY (1957) reported in this journal a study, using the mixed cell agglutination technique, of bladder tumour cells. His results showed a rough correlation between the strength of agglutination and the degree of malignancy as judged histologically, and he found a general pattern of weaker agglutination associated with greater malignancy. This was not constant, however, since one well differentiated tumour was totally unagglutinable, while two anaplastic pleomorphic growths gave normal, strong agglutination. The present study, suggested by Kay's work, reports the findings, using mixed cell agglutination, on thirty-two malignant tumours of the human stomach and large bowel.
METHODSSpecimens of gastric and colonic carcinomata were obtained from the operating theatre within fifteen minutes of resection. The viscus was opened, mucus and faeces gently washed away with tap water and the lesion examined. Two samples of tissue were then taken in each case. A small piece of the surface of the growth was removed with a sharp knife, and a piece of unaffected mucosa from an adjacent part of the organ was also taken. Both specimens were stored separately at -20°C. in 20 per cent glycerol in saline. The organ was then placed in formol saline for routine histological study. As soon as convenient, but usually within a few days, a mucosal cell suspension of both malignant and normal tissue was made, using a solution of oxidised ascorbic acid (Cowan, 1962). The suspensions were stored, like the tissues, in 20 per cent glycerol in saline at -200 C. A scraping of buccal cells from each patient was obtained in the post-operative period; these cells were stored in suspension in the same manner as the gastrointestinal cells and mixed cell agglutination performed on them served as a control of technique. Finally, a specimen of saliva, and often gastric juice in addition, was secured from each patient and the secretor status determined by the method of antibody-inhibition (Race and Sanger, 1958).Mixed cell agglutination was performed after the manner described by Coombs, Bedford and Rouillard (1956). Experience showed that with gastrointestinal cells, stronger mixed cell agglutination followed if the period of incubation with antibody was extended to two hours or more. With group 0 tissues, an extract of Ulex europaeus L. was used as anti H to detect H substance in the tissues.