Use of image cytometry to classify biliary and ampullary adenocarcinomas

OBJECTIVE: To create an objective classification system to perform TNM clas sification ampullary adenocarcinoma and cholangiocarcinoma using image cyto metric data derived from Feulgen-stained tumor nuclei. STUDY DESIGN: Surgically resected cases of ampullary adenocarcinoma and cho langiocarcinoma with established TNM classifications were selected on the b asis of available formalin-fixed, paraffin-embedded tissue. Fifteen numeric al variables related to morphometric, densitometric and textural features e ach tumor nucleus were recorded. We employed It methodology based on multiv ariate statistical tools to characterize the association of morphonuclear v ariables with TNM classification. The first step consisted of identifying a nd selecting representative nuclei of each T class. From this "purified" da ta set an objective classification system was created. The classification s ystem was assessed using internal and external validation. RESULTS: Employing ANOVA, all 15 variables were significantly associated wi th T classification, 11 of 15 with N and 4 with M. Multivariate analysis wa s employed to distinguish between TI, T2 and T3 lesions. Our methodology co rrectly classified 76% of T2 nuclei, 47% of T2 nuclei and 84% of T3 nuclei. Heterogeneity within an individual tumor was defined in 61% of cases inclu ded in the training set. Complete concordance between pathologic classifica tion and the classification system was observed in 71% of an independent va lidation.