The role of DNA index as a prognostic factor in early cervical carcinoma

The value of DNA index as a prognostic factor in early cervical cancers was investigated. A total of 124 patients who underwent radical hysterectomy for stages IB-IA cervical cancers from 1/1982 to 12/1985 were included. Paraffin blocks were available in only 98 patients for the analysis. After dewaxing, rehydrating, and enzyme disaggregation, cells were subjected to dual parameter flow cytometry. Tumor DNA index was calculated and the results were correlated with 5-year survival, stage, grade, tumor size, nodal metastasis, surgical margins, and lymphovascular invasion. There were 1% hypoploid, 7.3% diploid, 72.9% aneuploid, 16.7% tetraploid, and 2.1% hyperploid. At the end of 5 years, there were 69 alive and 27 dead patients with mean DNA indices of 1.50 +/- 0.3 and 1.70 +/- 0.3, respectively. t Test analysis revealed that mean DNA index of deceased patients was significantly higher than that of alive ones (P = 0.008). Survival analysis demonstrated the prognostic significance of DNA index 1.70 (P = 0.017). Median survival of patients with DNA index of 1.70 or greater was 36 months in contrast to 73.5 months for those with DNA index less than 1.70. Multivariate analysis subsequently confirmed DNA index of 1.70 as an independent prognostic indicator with a hazard ratio of 2.05.