THE RELATIONSHIP BETWEEN TUMOR VOLUME AND THE EXTENT OF SPREAD IN COLORECTAL-CARCINOMA

115 colorectal carcinomas were measured in three dimensions. To compar e the tumour volume, greatest linear dimension and the maximum thickne ss of colorectal carcinomas with the extent of spread. A formula was d evised for estimating tumour volume based on the oval shape of most ca rcinomas. Dukes staging was performed after xylene/alcohol fat clearan ce. The mean tumour volume of Dukes B tumours was greater than A tumou rs. The mean volume of C tumours was greater than that of A tumours. T he mean volume of Dukes B tumours was greater than that of C tumours. The greatest linear dimension and the tumour thickness measurements al so showed differences but were not as discriminating as the tumour vol ume. Using the Astler and Coller modification of Dukes staging, the me an tumour volume of C2 tumours was significantly greater than that of C1 tumours. Both C1 and C2 tumour volumes when considered separately w ere smaller than those of the B tumours. There was a significant posit ive correlation coefficient between tumour volume and the greatest lin ear dimension and also between tumour volume and the tumour thickness. There was no significant correlation within the C tumours between tum our volume and the number of lymph nodes with metastatic deposits. Col orectal carcinomas differ from other solid tumours in their growth pat tern and metastatic behaviour. There is no direct relationship between increasing tumour size and progression in the Dukes staging. Some tum ours appear to metastasize to lymph nodes while still small (C1 tumour s); other tumours appear not to metastasize to lymph nodes regardless of size (B tumours). Tumour volume is a more accurate estimation of tu mour size than either the single greatest linear dimension or the tumo ur thickness.