AN IMAGE-ANALYSIS STUDY OF DNA CONTENT IN EARLY COLORECTAL-CANCER

The DNA content of 168 consecutive T3,N0,M0 (Dukes' B, Astler-Coller B 2) colorectal cancers was studied using image analysis on formalin-fix ed paraffin-embedded tissues. 72 cases (43%) were classified as diploi d and the remaining 96 (57%) as non-diploid. After a median follow-up period of 6.7 years, a significant survival advantage was found for di ploid compared with non-diploid cases (logrank test; P = 0.008). The l ong-term (8 year) survival rate was 70% for diploid and 46% for non-di ploid tumours. Subgroup analysis showed that the survival advantage co nferred by tumour diploidy was greatest in large (greater than or equa l to 5 cm) cancers and was found both in colonic and rectal cancer cas es. These data indicate that tumour ploidy status measured by image an alysis might be useful in determining risk of colorectal cancer recurr ence and death in patients following resection of early colorectal can cer. (C) 1996 Elsevier Science Ltd