Rapid Flow Cytometry of Gastrointestinal Stromal Tumours Closely Matches the Modified Fletcher Classification.

Aim We aimed to develop a rapid, simple procedure and an algorithm for quantitative analysis and classification of the metastatic risk of gastrointestinal stromal tumours (GIST) for clinical use. Materials and methods Eighteen specimens from laparoscopic local gastrectomy were assessed by flow cytometry. We devised a new risk classification for GIST by combining flow cytometry parameters with tumour size and evaluated whether the combined parameters correlated with the modified Fletcher risk classification. Results We found a significant correlation between clinical prognostic factors (mitotic count and Ki-67 labelling index) and the flow cytometry parameters DNA ploidy, DNA index and S-phase fraction. The combined parameters established from tumour size and the flow cytometry parameters showed a high correlation with the modified Fletcher risk classification (p=0.0064). Flow cytometry had to be performed for approximately 10 minutes to determine the metastatic risk. Conclusion Rapid flow cytometry parameters can classify risk without the need for histological analysis.