Background: Lymphadenectomy has been widely used in the treatment of malignant
germ cell tumor of the ovary (OGCT), which is a kind of ovarian cancers occurred mostly in young
women and adolescent girls. But the clinical decision mainly depends on the doctor’s experience
without a well-defined guideline. This population-based study aimed to evaluate the prognostic
impact of lymphadenectomy in different stages of malignant germ cell tumors of the ovary.
Methods: Patients with known status of lymphadenectomy in different stages of OGCT were
explored from the Surveillance, Epidemiology, and End Results (SEER) program database from
1973 to 2013. We used propensity score matching algorithm to reduce the selection bias between the
two study groups. Survival curves, univariate and multivariate Cox proportional hazards model were
applied to evaluate the prognostic impact of lymphadenectomy in different stages of OGCT.
Results: We included 1,996 OGCT patients in the study, and 818 (41%) of them had lymph node
resection. Compared to the LND- group, patients with lymph node resection tended to be at stage II
and III, had larger tumor sizes and diagnosed as dysgerminoma. The influence of diagnosis ages,
marital status and tumor grades were significantly decreased by applying the propensity score
matching. Lymphadenectomy-positive (LND+) group demonstrated significantly worse survival than
the lymphadenectomy-negative (LND-) group in later stages (stage III, overall, P=0.027, cancerspecific,
P=0.006; stage IV, overall, P=0.034, cancer-specific, P=0.037). While, both the overall and
cancer-specific survival showed no significant differences between LND+ and LND- in stage I
(overall, P=0.411, cancer-specific, P=0.876) and stage II (overall, P=12, cancer-specific, P=0.061).
Univariate (overall, HR=1.497, CI=1.010-2.217, P=0.044; cancer-specific, HR=1.524, CI=1.067-
2.404, P=0.050) and multivariate (overall, HR=1.580, CI=1.046-2.387, P=0.030; cancer-specific,
HR=1.661, CI=1.027-2.686, P=0.039) Cox proportional model both verified the association between
the lymph node resection and better survival in the whole cohort.
Conclusion: Lymphadenectomy significantly increased the survival probability of OGCT patients in
stage III and IV, but had no significant influence on early-stage patients (stage I and II), indicating
lymphadenectomy should be performed in a stage-dependent manner in clinical utility.