ASSESSMENT DF INVASIVE GROWTH-PATTERN AND LYMPHOCYTIC INFILTRATION INCOLORECTAL-CANCER

A total of 122 specimens of colorectal cancer were re-assessed in rela tion to the reporting of invasive growth pattern (expanding vs, infilt rating) and presence or absence of peritumoral lymphocytic infiltrate as used in the Jass prognostic classification. Jass agreed with 69% of cases reported as infiltrating and 90% of those reported as expanding , This parameter was distributed similarly amongst Dukes B and C cases in the original assessment (P = 0.27), whereas in the reviewed data i nfiltrating cases were more likely to be staged as Dukes C (P = 0.04), Jass agreed with 44% of lymphocyte present and 94% of lymphocyte abse nt assessments, The original lymphocyte assessments showed no signific ant differences in distribution between Dukes A and B cases (P = 0.12) or B and C cases (P = 0.75), whereas the reviewed data showed signifi cant differences for A vs, B (P = 0.015) and B vs. C cases (P = 0.0025 ), Criteria for assessment were circulated to eight observers who revi sited 20 of the cases in which there was disagreement, Consensus agree ment with Jass was achieved in nine of 10 cases for invasive growth pa ttern and seven of 10 cases for lymphocyte infiltration (with two bein g evenly split). Most observers showed at least fair levels of agreeme nt with Jass and some achieved excellent levels of agreement, This stu dy indicates that assessment of criteria used in the Jass prognostic s ystem for colorectal cancer is less than optimal in routine practice, but is improved through the provision of simple guidelines.