Prognostic significance of DNA content in epithelial ovarian cancer

Abstract

The prognostic significance of cellular DNA content of epithelial ovarian cancer as determined by flow-cytometric analysis of paraffin-embedded tumor blocks was investigated in 87 patients. Seventy-five percent of tumors were DNA aneuploid and 25% were DNA diploid. The survival at median follow-up for patients with DNA diploid tumors (68%) was significantly longer than for DNA aneuploid tumors (49%; P = 0.003). The other prognostic factors which significantly affected survival were stage (P < 0.0001), tumor grade (P < 0.006), and residual disease at completion of initial surgery (P = 0.0005). When patients were separated into low-stage and advanced-stage disease, DNA content was a significant prognostic variable for survival in Stage I and II patients (P = 0.05). In Stage III and IV patients, DNA content had no independent prognostic significance. There were 33 patients who underwent second-look surgery. Seven of 15 patients (47%) with negative second-look surgery were DNA aneuploid, whereas 17 of 18 patients (94%) with positive second-look surgery were DNA aneuploid. Therefore, there was a much higher likelihood of positive second-look in the DNA aneuploid group (17/24) compared to the DNA diploid group (1/9) (P = 0.003). In addition for those patients with negative second-look surgery, none (0/8) of the DNA diploid tumors recurred; however, 3 of 7 (43%) of the DNA aneuploid tumors recurred and died. Cox proportional/hazards analysis showed that DNA content is an independent prognostic factor for survival in epithelial ovarian cancer. Aneuploid DNA content in ovarian tumors is also correlated with more aggressive biologic behavior, and therefore, a worse clinical course.