DNA ploidy, S-phase fraction, and G2 fraction as prognostic determinants in human pancreatic cancer.

The DNA ploidy, S-phase fraction (SPF), and G2 fraction of pancreatic cancer tissue was measured by flow cytometry in 95 patients. Forty-nine per cent (n = 47) had a diploid DNA index, and 51% (n = 48) of tumours were aneuploid. Aneuploid tumours and high-grade tumours had significantly higher S-phase and G2-fraction values than diploid tumours or low-grade tumours. Diploid and tetraploid tumours had a more favourable prognosis than non-tetraploid aneuploid tumours (p = 0.0020) during the mean follow-up of 6 years. The type of therapy (p = 0.07), histologic grade (p = 0.06), SPF (p = 0.1), and G2 fraction (p = 0.02) had predictive value in survival analysis as well. In multivariate survival analysis, including flow-cytometric, histologic, and clinical variables, diploidy and tetraploidy had independent predictive value. The results suggest that flow cytometry might be used in grading of pancreatic cancer. Such a grading would have practical value if new modes of therapy are being developed. Forty-one per cent of multiple samples had a heterogeneous DNA index when multiple samples were used. Consequently, flow cytometric analysis of pancreatic cancer using multiple samples is recommended.