Objective: The purpose of this study was to assess the rate of lymph node (LN) metastasis in comprehensively staged ovarian clear cell carcinoma (OCCC) clinically confined to the ovary and determine factors associated with LN metastasis.
Methods: We identified all cases of OCCC treated at 4 institutions from January 1994 through December 2011. We included cases with disease grossly confined to the ovary that had surgical staging performed, including at least 10 LNs sampled. Clinical and pathologic data were abstracted from electronic medical records, and a deidentified data set was compiled and processed at a single institution. Factors potentially associated with LN metastasis were tested. Appropriate statistical tests were performed.
Results: We identified 145 eligible cases that met the criteria for this analysis. Median age was 52.9 years (range, 30-81 years), and median total LN count was 19 (range, 10-74). Seven (4.8%) of 145 comprehensively staged cases had LN metastasis; 6 of these cases (4.1%) were isolated metastasis. Cytologic washings, peritoneal, omental, and fallopian tube involvement were not associated with nodal metastasis. Cases with ovarian surface involvement and positive cytology had a 37.5% incidence of LN positivity, which was statistically meaningful when compared with all other cases (P = 0.003).
Conclusions: Women who underwent comprehensive staging for clinical stage I OCCC had an LN metastasis rate of 4.8%. The subgroup of cases with both ovarian surface involvement and positive cytology had the highest incidence of LN metastasis. This may influence clinical decision making on whether to perform lymphadenectomy in patients with incidental OCCC found after salpingo-oophorectomy.