Prognostic assessment in stage I ovarian cancer using a discriminant analysis with clinicopathological and DNA flow cytometric data.

We have previously defined three types of tumor DNA histograms, which are associated with favourable, intermediate and poor prognosis of patients with ovarian cancer. In the present study we evaluated the value of DNA histogram type combined with clinicopathological data in predicting long-term clinical outcome in stage I ovarian cancer. A stepwise discriminant analysis was done to find out the best combination of prognostic parameters in the distinction of two groups of stage I ovarian cancer patients; those with less than 5-year overall survival (22 cases) and those with longer than 5-year recurrence-free survival (47 cases). DNA histogram and histological type as well as FIGO stage in that order proved to be the most discriminating parameters and their combination allowed the correct prediction of clinical outcome in 78% of stage I ovarian cancer patients. In stage Ia the proportion of correctly classified cases based on DNA histogram and histological type was 82%. If DNA histogram was omitted from the discriminant analysis, the combination stage and histological type correctly classified a significantly lower percentage (68%) of patients. DNA flow cytometry thus improved the prognostic evaluation in stage I ovarian cancer, but even when combined with conventional clinicopathological factors failed to give correct prognostic assessment in about 20% of patients with stage I ovarian cancer.