The relationship between tumour volume and the extent of spread in colorectal carcinoma.

115 colorectal carcinomas were measured in three dimensions. To compare the tumour volume, greatest linear dimension and the maximum thickness of colorectal carcinomas with the extent of spread. A formula was devised for estimating tumour volume based on the oval shape of most carcinomas. Dukes staging was performed after xylene/alcohol fat clearance. The mean tumour volume of Dukes B tumours was greater than A tumours. The mean volume of C tumours was greater than that of A tumours. The mean volume of Dukes B tumours was greater than that of C tumours. The greatest linear dimension and the tumour thickness measurements also showed differences but were not as discriminating as the tumour volume. Using the Astler and Coller modification of Dukes staging, the mean tumour volume of C2 tumours was significantly greater than that of C1 tumours. Both C1 and C2 tumour volumes when considered separately were smaller than those of the B tumours. There was a significant positive correlation coefficient between tumour volume and the greatest linear dimension and also between tumour volume and the tumour thickness. There was no significant correlation within the C tumours between tumour volume and the number of lymph nodes with metastatic deposits. Colorectal carcinomas differ from other solid tumours in their growth pattern and metastatic behaviour. There is no direct relationship between increasing tumour size and progression in the Dukes staging. Some tumours appear to metastasize to lymph nodes while still small (C1 tumours); other tumours appear not to metastasize to lymph nodes regardless of size (B tumours).(ABSTRACT TRUNCATED AT 250 WORDS)