[Clinicopathological studies of advanced rectal cancers--prediction of the degree of lymph node metastasis from histopathological finding of pre-operative biopsy specimens].

If we can predict pre-operatively the degree of lymph node metastasis, we can do a minimum radical operation and avoid the disturbance of urinary or sexual function. To predict the degree of lymph node metastasis we studied lymph vessel invasion (ly), microgland cancer nests and undifferentiated cancer cells (budding) in the pre-operative biopsy specimens and resected materials. Results are as follows; 1. The rate of ly in in biopsy specimens was low (13%), but when ly was present, the rate of lymph node metastasis was very high (100%). 2. The rate of budding in biopsy specimens was quite high (46%), and when budding was present, the rate of lymph node metastasis was quite high (79%). 3. Studies of serial continuous sections at 3 micron intervals showed that budding was closely related to ly. 4. Our study of resected specimens of rectal cancers revealed that the best position for the biopsy was in the margin of cancer tissue of the anal side including submucosa.