Objectives To compare the clinical-pathological features and survival outcomes of women with low grade and high grade serous epithelial ovarian cancer.

Methods A total of 87 patients with high grade (HGSOC) (79.8%) were retrospectively compared to 22 patients with low grade (LGSOC) staged surgically in Salah Azaiez Tunisian cancer center, between 2000 and 2010.

Results We performed primary debulking surgery in 89 patients (81.7%) and 20 patients (18.3%) underwent and interval debulking surgery. Maximal cytoreduction (R0) was achieved in 38 of patients (34.9%),32 patients had a residual disease ≤1 cm (29.4%) and 39 patients had a residual disease >1 cm (35.8%).The comparison of HGSOC to LGSOC by univariate analysis showed that HGSOC were associated to higher serum level of CA 125 >1000UI/ml (52.9% vs 27.3%,p=0.032), higher quantity of ascites >1 litre (47.1% vs 13.6%,p=0.004) with more frequent cacinomatosis in the upper abdomen (54% vs 27.3%,p=0.025) and bilateral tumors (79.3% vs 54.5%,p=0.018), with more tumor necrosis (59.8% vs 18.2%,p<0.0001) and lymphovascular invasion (50.6% vs 13.6%,p=0.002) and advanced FIGO stage III-IV (94.3% vs 63.6%,p<0.0001). Among the 60 patients who underwent lymphadenectomy (55%), HGSOC were associated to more lymph metastasis (LNM) (57.8% vs 26.7%, p=0.037) with higher LN ratio (15.04±24.20 vs 5.16.±10.59,p=0.034). and more frequent combined pelvic and paraaortic LNM (56.8% vs 26.7%, p=0.049).After a mean follow up of 44.73 months, HGSOC were associated to lower rates of 5-years overall survival (31.3% vs 50%,p=0.06) and recurrence free survival (27.9% vs 50%,p=0.112).

Conclusion HGSOC are correlated to a advanced stage and extended lymph node invasion.