Cytological diagnosis of cancer of the colon and rectum

Results of cytological examination in 120 cases of colon and rectum cancer during the 11-year period ending in 1968 prior to the practical use of fibercolonscope were first studied. At that time, quite favorable results were obtained in cancer of the lower colon and the rectum, but the results were not so satisfactory in cancer of the right side of the colon. After 1969 when the fibercolonscope was introduced into the clinical practice, the range of cytological diagnosis under direct vision was at once expanded to the entire colon. Consequently, diagnosis by the cytological method in 140 cases of cancer of the colon and rectum experienced in 6-year period between 1969 and 1974 revealed favorable results. The results of the cytological diagnosis in cancer of the right sied of the colon, previously not always favorable, improved markedly after the introduction of the cytological method under direct vision through fibercolonscope. When early cancer of the colon and rectum is defined as in early gastric cancer, 40 lesions in 36 patients were detected during the past 19 years. The rate of positive result in cases of early cancer obtained by various diagnostic methods was 83% by the cytological method, 78% by biopsy and 91% by polypectomy. In cases in which both biopsy and cytological method were used, one or both frequently gave positive results. These results would indicate the possibility of correct diagnosis in many cases through the combined use of the cytological method and biopsy, without polypectomy.