br response br Histological type br Residual disease br
disease rate and ECOG PS ≥1 rate. Survival data may have been affected by these patient char-acteristics.
Systematic lymphadenectomy may cause upstaging in patients with clinically early stage disease limited to pelvis which, in turn, enables the patients to receive su cient adjuvant chemotherapy. But there is no evidence showing that it is an independent prognostic factor. There are different results in the literature on the prognostic effect of lymphadenectomy in early stage ovarian cancer.18-22 In a retrospective study of T1 ovarian cancers,20 lymphadenectomy showed survival benefit, but in a randomized trial on T1 and T2 cancers its survival benefit was not demonstrated.21 In a randomized clinical study, in which the effect of lymphadenectomy on survival in early-stage ovarian cancer was evaluated, systematic lymphadenectomy did not con-tribute to survival compared to Sevoflurane node sampling.23 In our study, dissection of lymph node and its number in stage I-II patients had no effect on survival (P > 0.05). But progression-free survival was found to be longer in patients with >10 lymph nodes removed than 1-10 lymph nodes removed.
Cytoreductive surgery is one of the cornerstones in management of ovarian cancer. Lym-phadenectomy comprises an important part of cytoreductive surgery, but its therapeutic value is still controversial. The contribution of number and region of lymph node dissection to survival
Fig. 1. Overall survival (OS) in patients with or without lymphadenectomy.
Effect of clinical and surgical characteristics on overall and progression free survival.
region Pelvic + paraaortic
Fig. 2. Overall survival (OS) in patients w.r.t. number of lymph nodes removed.
in advanced-stage ovarian cancer has been demonstrated in many studies.24-30 In a random-ized clinical study conducted by Benedetti Pacini et al to evaluate the role of systematic lym-phadenectomy in advanced-stage patients in 2005, it was shown that systematic lymphadenec-tomy improved 6-month disease-free survival compared to lymph node sampling.14 In a retro-spective study (stage IIIC, in 189 patients) both PFS and OS were better in patients with sys-temic lymphadenectomy.27 In another study, conducted by Burghardt et al where 82 patients diagnosed with stage III EOC who were grouped as pelvic lymphadenectomy performed and not performed, 5-year survival rates were 54%, 13% respectively.31 Similarly, in a SEER meta-analysis conducted in 2007, where 13 918 stage III-IV patients were divided into 6 groups according to number of lymph nodes removed (0, 1, 2-5, 6-10, and 11-20), it was shown that 5-year survival was improved as lymph node dissection increased.1 Similar results have been obtained in our study. When the patients grouped based on the number of lymph nodes removed as, 1-5, 6-10, 11-20, and >20, progression-free survival and median survival time was found to be significantly better with increasing number of lymph nodes removed in stage III-IV patients (P < 0.05).
Retroperitoneal lymph node involvement occurs in nearly 4%-25% of women with early ovar-ian cancer, and 50%-80% of women with advanced ovarian cancer.19 Previous studies mainly focused on systematic pelvic lymphadenectomy. It has also been suggested that nodal ovarian cancer metastases may be less sensitive to systemic chemotherapy because of diminished blood supply, and thus lymphadenectomy in patients with advanced disease is therapeutic as a result of maximal debulking.32
In a study conducted in 2014 concerning this issue, an improvement in survival was demon-strated with dissection of paraaortic lymph nodes in patients with positive metastatic lymph node.33 In our study, survival was found to be improved in patients with pelvic and paraaortic lymph nodes removed than only pelvic lymph node removed.
Cox-regression model of overall survival (OS) in ovarian cancer.
(pelvic, pelvic + paraaortic)
Our study has some features that might be viewed as potential weaknesses. First is the ret-rospective design of the study. Second is some of the patients were operated in different clinics other than our clinic. Lack of some prognostic factors, such as, presence of ascites, blood loss, operative time, perioperative morbidity, postoperative mortality can also be evaluated as another shortcoming of the study.