Large-scale genomic instability predicts long-term outcome for women with invasive stage I ovarian cancer

Background: The objective was to evaluate the value of DNA ploidy using high-resolution image cytometry in predicting long-term survival of patients with early ovarian cancer. Patients and methods: A retrospective analysis of 284 cases with FIGO stage I ovarian carcinoma treated during the period 1982-1989 was performed. Clinical follow-up information was available for all patients. Results: Patients with diploid and tetraploid tumors had a 10-year relapse-free survival of 95% and 89%, respectively, compared with 70% and 29% for polyploid and aneuploid tumors, respectively. DNA ploidy analysis was the strongest predictor of survival in multivariate analysis (diploid/tetraploid versus polyploid/aneuploid; relative hazard 9.0) followed by histological grade, including clear cell tumors in the group of poorly differentiated tumors (grade 1-2 versus grade 3 or clear cell; relative hazard 2.7), and FIGO stage (Ib/Ic versus Ia; relative hazard 2.0). In a stratified Kaplan-Meier analysis, patients with grade 1-2. diploid or tetraploid tumors had a 10-year relapse-free survival of 95%, forming a low-risk group. Patients with grade 3 or clear cell, diploid or tetraploid tumors had 10-year relapse-free survival of 86%, forming an intermediate-risk group, while all patients with aneuploid/polyploid tumors formed a high-risk group, with 10-year relapse-free survival of 34%. Conclusions: This study points to the importance of including DNA ploidy analysis by image cytometry when selecting patients with early ovarian cancer for adjuvant treatment after surgery.