Prognostic significance of preoperative DNA flow cytometry in surgically-treated cervical cancer.

OBJECTIVE: To evaluate the prognostic significance of preoperative DNA flow cytometry compared with other clinical and histologic variables in cervical carcinoma. STUDY DESIGN: Sixty-four patients with FIGO Stage Ib-II cervical cancer treated with radical abdominal hysterectomy and systematic pelvic lymphadenectomy were analyzed. The mean follow-up was 3.4 (range 0.3-9.8) years. DNA flow cytometry was performed with fresh tumor tissue. Four biopsies were recut from the surgical specimen within 30 minutes of the operation. The ectocervix was divided into four quadrants and a specimen obtained from each. DNA-low-grade tumors (diploid, near-diploid, tetraploid and near-tetraploid) were distinguished from DNA-high-grade tumors (aneuploid and hypoploid). Carcinomas with more than one non-diploid stem line were considered heterogeneous. An S phase fraction >7% was classified as low, 7% - < 14% as moderate, and > or = 14 as high. DNA ploidy, DNA heterogeneity, S phase fraction and various clinical and histological variables were related to disease-free survival. RESULTS: In the univariate analysis patients with DNA-low-grade carcinomas had significantly better disease-free survival than patients with DNA-high-grade tumors (82% vs 45%, p = 0.021). Carcinomas with an S-phase fraction < 7% were associated with better disease-free survival (0.8) than those with an S-phase fraction 7% - > 14% (0.62) and those with > or = 14% (0.64), but this was not statistically significant. Cox stepwise regression analysis showed DNA-heterogeneity, age, grade, parametrial involvement and extrapelvic metastasis to be independent prognostic factors. CONCLUSION: DNA ploidy and DNA heterogeneity are of prognostic importance in cervical cancer. DNA flow cytometry may be used preoperatively to identify low-risk and high-risk patients within a given stage.