Clinical Features And Prognosis Of Pure And Mixed Ovarian Clear Cell Carcinoma

Objective Investigate the clinical characteristics and prognosis of pure ovarian clear cell carcinoma(OCCC)and mixed OCCC(clear cells mixed with other pathological subtypes).Methods Retrospective analysis was performed on the clinicopathological data and the prognosis factors of 85 patients with OCCC,including 40 patients with pure OCCC and 45 patients with mixed OCCC,compared with 49 patients with ovarian high-grade serous carcinoma(HGSC),23 patients with ovarian high grade endometrial carcinoma(HGEC)cured between January 2008 and April 2016 in Zhejiang Cancer Hospital.Results1.A total of 85 patients with ovarian clear cell carcinoma were included for prognostic analysis,and a total of 78 patients met the 5-year follow-up.The median age was 52 years,the median follow-up time was 75.20 months,51(58.8%)patients relapsed or died,and 38(44.7%)patients died.The 5-year PFS rate was 40.2%,and the 5-year OS rate was 57.5%.2.The progression-free survival(PFS)of patients with pure OCCC was superior to that of patients with mixed OCCC(P=0.034).The 5-year PFS rate of patients in the pure group was about 57.5%,and the median PFS was not achieved.The 5-year PFS rate of patients in the mixed group was about 25.2%,and the median PFS was 25.57 months.However,there was no significant difference in Overall Survival(OS)(P>0.05).Further analysis found that in the early cases(?-? stages),there was no significant difference on the outcome(P>0.05),but in the late cases(?-? stages),OS of pure group was significantly worse than that of mixed group,5 years survival rates were 21.4%and 43.5%,and the median OS was 12.27 months,52.00 months respectively(P=0.015).Compared with mixed OCCC,pure OCCC had larger diameter,lower preoperative CA125,less abdominal water,larger number of premenopausal patients,earlier stage,more unilateral tumors,less lymph node metastasis,and lower incidence of vascular tumor embolism(P<0.05).However,there were no significant differences between the two groups in age,residual tumor,BMI,tumor capsule status,peritoneal washing cytology,whether endometriosis,peritoneal metastasis(P>0.05).3.The clinical features and prognosis of mixed OCCC were similar to that of HGSC and HGEC.The median PFS of mixed OCCC and HGSC was 25.57 months and 37.5 months(P=0.309).The median OS was 62.50 months and 81.20 months(P=0.419).The median PFS of mixed OCCC and HGEC was 25.57 months and 31.20 months(P=0.471).The median OS was 62.50 months and 82.53 months(P=0.643).Compared with HGSC,the peritoneal metastasis rate of mixed OCCC was lower(P<0.05),while compared with HGEC,the tumor diameter of mixed OCCC was smaller,the lymph node metastasis rate was higher and the peritoneal metastasis rate was lower(P<0.05).4.The clinical characteristics of pure OCCC and HGSC were greatly different.The prognosis of early stage patients was similar,but the prognosis of advanced stage pure OCCC was worse than that of advanced stage HGSC.The median PFS was 8.97 months,30.47 months(P=0.004)and the median OS was 12.27 months,81.20 months(P=0.001).Some of the clinical features of pure OCCC and HGEC were different,and some were similar.There was no significant difference in age,tumor diameter and lymph node metastasis rate between the two groups(P>0.05).The prognosis of patients in the two groups was similar in early stage,and the prognosis of patients with advanced pure OCCC was worse than that of patients with advanced HGEC.The median PFS was 8.97 months,30.37 months(P=0.021).The median OS was 12.27 months,82.53 months(P=0.019).5.Prognostic factors were analyzed for all the OCCC patients.In early OCCC patients,no significant influence of clinical factors on prognosis was found(P>0.05).In patients with advanced OCCC,multivariate analysis showed that the independent prognostic factors were pure OCCC(HR=0.273,95.0%CI:0.116-0.641,P=0.003),positive peritoneal washing cytology(HR=6.170,95.0%CI:1.425-26.711,P=0.015),and residual tumor>1cm(HR=3.537,95.0%CI:1.568-7.979,P=0.002).Conclusion Pure OCCC and mixed OCCC had different biological behaviors,and there was no significant difference in the prognosis of early patients.However,in advanced clear cell carcinoma,the prognosis of pure OCCC was worse.The different prognosis may be result from the sensitivity of different pathological components to chemotherapy.It is recommended that a unique first-line chemotherapy regimen,which is different from conventional chemotherapy for advanced pure OCCC,is urgently needed to improve prognosis.