Ploidy and S-phase fraction are correlated with lymphovascular space invasion that is predictive of outcomes in endometrial cancer

Background: Pathological detection of lymphovascular space invasion (LVSI) is a useful prognostic marker for patients with endometrial cancer. However, LVSI is criticized for its subjectivity and poor reproducibility. To improve the outcomes of patients with endometrial cancer, we evaluated objective parameters associated with LVSI to generate more accurate LVSI assessments and to identify patients with high-risk disease. Methods: We reviewed the medical records of 137 patients with endometrial cancer. Flow cytometry was used to determine DNA ploidy and S-phase fraction. Estrogen and progesterone receptor (ER and PR) levels and p53 and k-ras mutational status were tested. Results: LVSI was found in 36 patients (26.3%). Patients with LVSI had significantly decreased recurrence-free survival and overall survival compared to those without LVSI. Aneuploid tumors were significantly more frequent in LVSI-positive patients compared with LVSI-negative patients (odds ratio = 5.208, P < 0.001). With the exception of p53 mutational status, there was a statistically significant relationship between LVSI and other parameters tested. However, by multivariate analysis, DNA ploidy and S-phase fraction were significantly correlated with LVSI (P = 0.034 and 0.001, respectively). Conclusion: Ploidy and S-phase fraction correlate with LVSI, which is a significant independent predictor of clinical outcome in patients with endometrial cancer.