Effects Of Retroperitoneal Lymph Node Dissection On The Prognosis Of Borderline Ovarian Tumors: A Meta-analysis

Objective: To provide evidence on the basis of evidence-based medicine for the clinical issue about whether or not to perform retroperitoneal lymph node dissection for ovarian borderline tumors.Methods: A thorough computer search on the related topic was conducted by using foregin databases including Pub Med, Cochrane Library, Medline, Embase, and Sci Finder, and Chinese databases including CNKI, Wanfang Data, and VIP Database. Information from both English and Chinese publications between Januarary 1, 1990 and Januarary 1, 2016 was retrieved and sorted based on inclusion and exclusion criteria. The quality was evaluated using evaluation standards of non-randomized controlled trials. Meta-analysis was conducted by using Rev Man 5.3 for homogeneity study.Results: Retrospective case-control studies from 13 publications are included regarding the comparisons of borderline ovarian tumor cases with and without lymph node dissection and the comparisons of cases with positive and negative lymph nodes.The results indicate the following. Recurrence rate and surgical complication occurrence rate of borderline ovarian tumors in the group with lymph node dissection are both higher than the group without lymph node dissection. Recurrence rate of serous borderline ovarian tumor in the group with lymph node dissection is also higher than the group without lymph node dissection. The differences of the above occurrence and recurrence rates show statistical significance(P < 0.05).However, the rate differences between the following comparison groups show no statistical significance(P>0.05): the difference between recurrence rates of mucinous borderline ovarian tumor or FIGO I borderline ovarian tumor in the group with lymph node dissection and in the group without lymph node dissection; the difference between recurrence rates of positive group and negative group for borderline ovarian tumor with lymph node dissection; the difference between recurrence rates of positive group and negative group for serous borderline ovarian tumor with lymph node dissection; the difference between mortality rates of the groups of borderline ovarian tumor with and without lymph node dissection.Moreover, in the contents of descriptive comparisons, blood loss and hospitalization days are both higher in the group with lymph node dissection than without lymph node dissection, and 5-year disease-free survival rate is lower in the group with lymph node dissection than without lymph node dissection. These differences show statistical significance(P<0.05). No statistical significance was found for total survival time, disease-free survival time, recurrence-free time, 5-year survival rate and 10-year survival rate of the group with or without lymph node dissection. The 10-year disease-free survival rate and mortality rate at follow-up deadline(average 55 months) also show no statistical significance between groups with positive and negative lymph nodes(P > 0.05).Conclusions:1. The removal of retroperitoneal lymph nodes cannot reduce the recurrence rate and mortality rate of borderline ovarian tumor, but can increase the occurrence rate of surgical complications.2. Lymph node dissection cannot reduce the recurrence rates of serous and mucinous borderline ovarian tumor and FIGO I borderline ovarian tumor.3. Whether lymph node is positive or not doesn’t affect the recurrence rate of borderline ovarian tumor with lymph node dissection.4. Whether lymph node is positive or not doesn’t affect the recurrence rate of serous borderline ovarian tumor with lymph node dissection, either.5. Performing lymph node dissection may lead to increased surgical blood loss and hospitalization days for borderline ovarian tumor, and it may also lead to decreased 5-year disease-free survival rate, but it may not affect the total survival time, disease-free survival time, recurrence-free time, 5-year survival rate and 10-year survival rate.6. For borderline ovarian tumor with lymph node dissection, whether lymph node is positive or not doesn’t affect the 10-year disease-free survival rate and mortality rate at follow-up deadline(average 55 months).