Ulcerative colitis and colorectal carcinoma - DNA-profile, laminin-5 gamma2 chain and cyclin A expression as early markers for risk assessment

Background: Ulcerative colitis patients are at increased risk for developin g colorectal carcinomas. Despite expensive surveillance programmes, clinica l practice reflects an uncertainty in individual risk assessment. The aim o f the study was to evaluate independent cellular features with possible pre dictive value. Methods: Two patient groups were selected: group A comprised 8 patients with ulcerative colitis-associated colorectal carcinomas, group B comprised 16 ulcerative colitis patients with risk factors (duration of disease, extent of inflammation, epithelial dysplasias). A total of 683 par affin-embedded mucosal biopsies were retrospectively evaluated for inflamma tory activity, grade of dysplasia. ploidy status, laminin-5 gamma2 chain an d cyclin A expression. Results: Mild or moderate inflammatory activity was present in 78% of all biopsies. low- or high-grade dysplasia in 5.5%. There was no difference in inflammatory activity and dysplasia between patient g roups. In group A. 75% of the biopsies exhibited aneuploid DNA distribution patterns. Group B showed mainly proliferative-diploid cell populations (85 % / P = 0.006). Laminin-5 gamma2 chain was expressed in 13% of all biopsies , with a higher frequency in group A (P = 0.002). Cyclin A expression was f ound in 98% of all biopsies, with a higher number of immunopositive cells i n group A biopsies (P = 0.014). Conclusions: Combined nuclear DNA assessmen t, laminin-5 gamma2 chain and cyclin A expression may help to identify ulce rative colitis patients with an increased risk for cancer development.