Incidence and predictive factors for recurrent clear cell ovarian carcinoma: results from a single center in Thailand.

OBJECTIVE

We aimed to study the incidence and predictive factors of recurrent clear cell ovarian carcinoma (CCC) and evaluate the oncological outcomes after recurrence.

METHODS

This was a retrospective study of 134 CCC cases diagnosed between 2005 and 2020. Clinicopathological data and oncological outcomes were extracted and evaluated. Patients with co-malignancy, mixed pathological type, or incomplete data were excluded. Descriptive statistics, univariate and multivariable analyses, and Kaplan-Meier survival probability estimates were completed. A proportional hazards model was used to assess the association between the prognostic factors with progression-free survival (PFS), overall survival (OS), and post-recurrence survival.

RESULTS

A total of 134 patients with CCC were enrolled. The incidence of recurrent CCC was 33.6% (45/134). The median PFS was 12.8 months (95% confidence interval [CI], 9.66-18.9) in the recurrence group and 3.3 months (95% CI, 1.15-4.4) in the refractory group. Residual tumor from surgical outcome, ascites cytology, and lymphovascular space invasion (LVSI) were independent prognostic factors for PFS. The significant variables were residual tumor (sub-optimal surgery vs. optimal surgery) (hazard ratio [HR], 2.68; 95% CI, 1.48-4.87; P=0.002), ascites cytology (positive vs. negative) (HR, 2.8; 95% CI, 1.58-4.98; P=0.002), and LVSI (positive vs. negative) (HR, 2.14; 95% CI, 1.18-3.86; P=0.04). The median postrecurrence survival was 13.96 months (95% CI, 10.61-26.2) in the recurrence group.

CONCLUSION

CCC has a high rate of recurrence. Sub-optimal surgery, positive ascites cytology, and LVSI indicated a worse prognosis for PFS. Optimal cytoreductive surgery is an important part of primary treatment to improve survival in patients with CCC.