Evaluation of DNA ploidy combined with a cytometric proliferation index ofimprints from core needle biopsies in prostate cancer

Objective: To evaluate if DNA ploidy analysis with a proliferation index (P I) derived from DNA cytometry of imprints from core needle biopsies predict s disease progression in patients with prostate cancer. Methods: Touch impr ints were done on a consecutive series of core needle biopsies taken by the same urologist from 240 patients with suspected prostate cancer, 137 (46%) of whom were found to have prostate cancer and included in the study. Scat tered cells to the right of the image cytometry (ICM) ploidy-establishing p eak, the S-phase fraction, and those in the G2M area of the ICM DNA histogr ams, were counted in percent of the total number of tumor cells, this value being designated the ICM PI. Based on previous results in archival fine ne edle aspiration material, the following classification was used: DNA group I, diploid tumor with a low PI; DNA group II, diploid tumor with an interme diate PI and tetraploid tumor with a low or intermediate PI, and DNA group III, diploid or tetraploid tumor with high PI and all tumors with an aneupl oid pattern. Results: Correlation was found to exist between DNA groups I-I II and Gleason score (GS) (p < 0.0001), T-stage (p = 0.006), M-stage (p = 0 .009) and disease progression (p < 0.0001). Among the 39 patients who had c urative treatment and GS 5-7, the progression-free survival rate was 100% i n DNA group I, as compared with only 38% in DNA group II and 55% in DNA gro up III within the follow-up period (p = 0.008). Conclusion: DNA ploidy comb ined with a PI derived from image cytometry of imprints from core needle bi opsies yields additional prognostic information in patients with GS 5-7. Di ploid tumors with a low PI (DNA group I) are associated with a low risk of disease progression.