Prognostic significance of systematic lymphadenectomy as part of primary debulking surgery in patients with advanced ovarian cancer

Residual Disease Threshold After Primary Surgical Treatment for Advanced Epithelial Ovarian Cancer, Part 1: A Systematic Review and Network Meta-Analysis

BACKGROUND

We present a systematic review and network meta-analysis (NMA) that is the precursor underpinning the Bayesian analyses that adjust for publication bias, presented in the same edition in AJT. The review assesses optimal cytoreduction for women undergoing primary advanced epithelial ovarian cancer (EOC) surgery.

AREAS OF UNCERTAINTY

To assess the impact of residual disease (RD) after primary debulking surgery in women with advanced EOC. This review explores the impact of leaving varying levels of primary debulking surgery.

DATA SOURCES

We conducted a systematic review and random-effects NMA for overall survival (OS) to incorporate direct and indirect estimates of RD thresholds, including concurrent comparative, retrospective studies of ≥100 adult women (18+ years) with surgically staged advanced EOC (FIGO stage III/IV) who had confirmed histological diagnoses of ovarian cancer. Pairwise meta-analyses of all directly compared RD thresholds was previously performed before conducting this NMA, and the statistical heterogeneity of studies within each comparison was evaluated using recommended methods.

THERAPEUTIC ADVANCES

Twenty-five studies (n = 20,927) were included. Analyses demonstrated the prognostic importance of complete cytoreduction to no macroscopic residual disease (NMRD), with a hazard ratio for OS of 2.0 (95% confidence interval, 1.8-2.2) for <1 cm RD threshold versus NMRD. NMRD was associated with prolonged survival across all RD thresholds. Leaving NMRD was predicted to provide longest survival (probability of being best = 99%). The results were robust to sensitivity analysis including only those studies that adjusted for extent of disease at primary surgery (hazard ratio 2.3, 95% confidence interval, 1.9-2.6). The overall certainty of evidence was moderate and statistical adjustment of effect estimates in included studies minimized bias.

CONCLUSIONS

The results confirm a strong association between complete cytoreduction to NMRD and improved OS. The NMA approach forms part of the methods guidance underpinning policy making in many jurisdictions. Our analyses present an extension to the previous work in this area.

Impact of residual disease as a prognostic factor for survival in women with advanced epithelial ovarian cancer after primary surgery

BACKGROUND

Ovarian cancer is the seventh most common cancer among women and a leading cause of death from gynaecological malignancies. Epithelial ovarian cancer is the most common type, accounting for around 90% of all ovarian cancers. This specific type of ovarian cancer starts in the surface layer covering the ovary or lining of the fallopian tube. Surgery is performed either before chemotherapy (upfront or primary debulking surgery (PDS)) or in the middle of a course of treatment with chemotherapy (neoadjuvant chemotherapy (NACT) and interval debulking surgery (IDS)), with the aim of removing all visible tumour and achieving no macroscopic residual disease (NMRD). The aim of this review is to investigate the prognostic impact of size of residual disease nodules (RD) in women who received upfront or interval cytoreductive surgery for advanced (stage III and IV) epithelial ovarian cancer (EOC).

OBJECTIVES

To assess the prognostic impact of residual disease after primary surgery on survival outcomes for advanced (stage III and IV) epithelial ovarian cancer. In separate analyses, primary surgery included both upfront primary debulking surgery (PDS) followed by adjuvant chemotherapy and neoadjuvant chemotherapy followed by interval debulking surgery (IDS). Each residual disease threshold is considered as a separate prognostic factor.

SEARCH METHODS

We searched CENTRAL (2021, Issue 8), MEDLINE via Ovid (to 30 August 2021) and Embase via Ovid (to 30 August 2021).

SELECTION CRITERIA

We included survival data from studies of at least 100 women with advanced EOC after primary surgery. Residual disease was assessed as a prognostic factor in multivariate prognostic models. We excluded studies that reported fewer than 100 women, women with concurrent malignancies or studies that only reported unadjusted results. Women were included into two distinct groups: those who received PDS followed by platinum-based chemotherapy and those who received IDS, analysed separately. We included studies that reported all RD thresholds after surgery, but the main thresholds of interest were microscopic RD (labelled NMRD), RD 0.1 cm to 1 cm (small-volume residual disease (SVRD)) and RD > 1 cm (large-volume residual disease (LVRD)).

DATA COLLECTION AND ANALYSIS

Two review authors independently abstracted data and assessed risk of bias. Where possible, we synthesised the data in meta-analysis. To assess the adequacy of adjustment factors used in multivariate Cox models, we used the 'adjustment for other prognostic factors' and 'statistical analysis and reporting' domains of the quality in prognosis studies (QUIPS) tool. We also made judgements about the certainty of the evidence for each outcome in the main comparisons, using GRADE. We examined differences between FIGO stages III and IV for different thresholds of RD after primary surgery. We considered factors such as age, grade, length of follow-up, type and experience of surgeon, and type of surgery in the interpretation of any heterogeneity. We also performed sensitivity analyses that distinguished between studies that included NMRD in RD categories of < 1 cm and those that did not. This was applicable to comparisons involving RD < 1 cm with the exception of RD < 1 cm versus NMRD. We evaluated women undergoing PDS and IDS in separate analyses.

MAIN RESULTS

We found 46 studies reporting multivariate prognostic analyses, including RD as a prognostic factor, which met our inclusion criteria: 22,376 women who underwent PDS and 3697 who underwent IDS, all with varying levels of RD. While we identified a range of different RD thresholds, we mainly report on comparisons that are the focus of a key area of clinical uncertainty (involving NMRD, SVRD and LVRD). The comparison involving any visible disease (RD > 0 cm) and NMRD was also important. SVRD versus NMRD in a PDS setting In PDS studies, most showed an increased risk of death in all RD groups when those with macroscopic RD (MRD) were compared to NMRD. Women who had SVRD after PDS had more than twice the risk of death compared to women with NMRD (hazard ratio (HR) 2.03, 95% confidence interval (CI) 1.80 to 2.29; I2 = 50%; 17 studies; 9404 participants; moderate-certainty). The analysis of progression-free survival found that women who had SVRD after PDS had nearly twice the risk of death compared to women with NMRD (HR 1.88, 95% CI 1.63 to 2.16; I2 = 63%; 10 studies; 6596 participants; moderate-certainty). LVRD versus SVRD in a PDS setting When we compared LVRD versus SVRD following surgery, the estimates were attenuated compared to NMRD comparisons. All analyses showed an overall survival benefit in women who had RD < 1 cm after surgery (HR 1.22, 95% CI 1.13 to 1.32; I2 = 0%; 5 studies; 6000 participants; moderate-certainty). The results were robust to analyses of progression-free survival. SVRD and LVRD versus NMRD in an IDS setting The one study that defined the categories as NMRD, SVRD and LVRD showed that women who had SVRD and LVRD after IDS had more than twice the risk of death compared to women who had NMRD (HR 2.09, 95% CI 1.20 to 3.66; 310 participants; I2 = 56%, and HR 2.23, 95% CI 1.49 to 3.34; 343 participants; I2 = 35%; very low-certainty, for SVRD versus NMRD and LVRD versus NMRD, respectively). LVRD versus SVRD + NMRD in an IDS setting Meta-analysis found that women who had LVRD had a greater risk of death and disease progression compared to women who had either SVRD or NMRD (HR 1.60, 95% CI 1.21 to 2.11; 6 studies; 1572 participants; I2 = 58% for overall survival and HR 1.76, 95% CI 1.23 to 2.52; 1145 participants; I2 = 60% for progression-free survival; very low-certainty). However, this result is biased as in all but one study it was not possible to distinguish NMRD within the < 1 cm thresholds. Only one study separated NMRD from SVRD; all others included NMRD in the SVRD group, which may create bias when comparing with LVRD, making interpretation challenging. MRD versus NMRD in an IDS setting Women who had any amount of MRD after IDS had more than twice the risk of death compared to women with NMRD (HR 2.11, 95% CI 1.35 to 3.29, I2 = 81%; 906 participants; very low-certainty).

AUTHORS' CONCLUSIONS

In a PDS setting, there is moderate-certainty evidence that the amount of RD after primary surgery is a prognostic factor for overall and progression-free survival in women with advanced ovarian cancer. We separated our analysis into three distinct categories for the survival outcome including NMRD, SVRD and LVRD. After IDS, there may be only two categories required, although this is based on very low-certainty evidence, as all but one study included NMRD in the SVRD category. The one study that separated NMRD from SVRD showed no improved survival outcome in the SVRD category, compared to LVRD. Further low-certainty evidence also supported restricting to two categories, where women who had any amount of MRD after IDS had a significantly greater risk of death compared to women with NMRD. Therefore, the evidence presented in this review cannot conclude that using three categories applies in an IDS setting (very low-certainty evidence), as was supported for PDS (which has convincing moderate-certainty evidence).

Ultra-radical (extensive) surgery versus standard surgery for the primary cytoreduction of advanced epithelial ovarian cancer

BACKGROUND

Ovarian cancer is the seventh most common cancer among women and the leading cause of death in women with gynaecological malignancies. Opinions differ regarding the role of ultra-radical (extensive) cytoreductive surgery in ovarian cancer treatment.

OBJECTIVES

To evaluate the effectiveness and morbidity associated with ultra-radical/extensive surgery in the management of advanced-stage epithelial ovarian cancer.

SEARCH METHODS

We searched CENTRAL (2021, Issue 11), MEDLINE Ovid and Embase Ovid up to November 2021. We also searched registers of clinical trials, abstracts of scientific meetings, reference lists of included studies and contacted experts in the field.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or non-randomised studies (NRS), analysed using multivariate methods, that compared ultra-radical/extensive and standard surgery in women with advanced primary epithelial ovarian cancer.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed whether potentially relevant studies met the inclusion criteria, abstracted data and assessed the risk of bias. We identified three NRS and conducted meta-analyses where possible.

MAIN RESULTS

We identified three retrospective observational studies for inclusion in the review. Two studies included women exclusively undergoing upfront primary debulking surgery (PDS) and the other study including both PDS and interval debulking surgical (IDS) procedures. All studies were at critical risk of bias due to retrospective and non-randomised study designs. Meta-analysis of two studies, assessing 397 participants, found that women who underwent radical procedures, as part of PDS, may have a lower risk of mortality compared to women who underwent standard surgery (adjusted HR 0.60, 95% CI 0.43 to 0.82; I2 = 0%; very low-certainty evidence), but the evidence is very uncertain. The results were robust to a sensitivity analysis including women with more-extensive disease (carcinomatosis) (adjusted HR 0.61, 95% CI 0.44 to 0.85; I2 = 0%; n = 283, very low-certainty evidence), but the evidence is very uncertain. One study reported a comparison of radical versus standard surgical procedures associated with both PDS and IDS procedures, but a multivariate analysis was only undertaken for disease-free survival (DFS) and therefore the certainty of the evidence was not assessable for overall survival (OS) and remains very low. The lack of reporting of OS meant the study was at high risk of bias for selective reporting of outcomes. One study, 203 participants, found that women who underwent radical procedures as part of PDS may have a lower risk of disease progression or death compared to women who underwent standard surgery (adjusted HR 0.62, 95% CI 0.42 to 0.92; very low-certainty evidence), but the evidence is very uncertain. The results were robust to a sensitivity analysis in one study including women with carcinomatosis (adjusted HR 0.52, 95% CI 0.33 to 0.82; n = 139; very low-certainty evidence), but the evidence is very uncertain. A combined analysis in one study found that women who underwent radical procedures (using both PDS and IDS) may have an increased chance of disease progression or death than those who received standard surgery (adjusted HR 1.60, 95% CI 1.11 to 2.31; I2 = 0%; n = 527; very low-certainty evidence), but the evidence is very uncertain. In absolute and unadjusted terms, the DFS was 19.3 months in the standard surgery group, 15.8 in the PDS group and 15.9 months in the IDS group. All studies were at critical risk of bias and we only identified very low-certainty evidence for all outcomes reported in the review. Perioperative mortality, adverse events and quality of life (QoL) outcomes were either not reported or inadequately reported in the included studies. Two studies reported perioperative mortality (death within 30 days of surgery), but they did not use any statistical adjustment. In total, there were only four deaths within 30 days of surgery in both studies. All were observed in the standard surgery group, but we did not report a risk ratio (RR) to avoid potentially misleading results with so few deaths and very low-certainty evidence. Similarly, one study reported postoperative morbidity, but the authors did not use any statistical adjustment. Postoperative morbidity occurred more commonly in women who received ultra-radical surgery compared to standard surgery, but the certainty of the evidence was very low.

AUTHORS' CONCLUSIONS

We found only very low-certainty evidence comparing ultra-radical surgery and standard surgery in women with advanced ovarian cancer. The evidence was limited to retrospective, NRSs and so is at critical risk of bias. The results may suggest that ultra-radical surgery could result in improved OS, but results are based on very few women who were chosen to undergo each intervention, rather than a randomised study and intention-to-treat analysis, and so the evidence is very uncertain. Results for progression/DFS were inconsistent and evidence was sparse. QoL and morbidity was incompletely or not reported in the three included studies. A separate prognostic review assessing residual disease as a prognostic factor in this area has been addressed elsewhere, which demonstrates the prognostic effect of macroscopic debulking to no macroscopic residual disease. In order to aid existing guidelines, the role of ultra-radical surgery in the management of advanced-stage ovarian cancer could be addressed through the conduct of a sufficiently powered, RCT comparing ultra-radical and standard surgery, or well-designed NRSs, if this is not possible.

Systematic lymph node dissection during interval debulking surgery for advanced epithelial ovarian cancer: a systematic review and meta-analysis

Objective

To evaluate the efficacy and safety of systematic lymph node dissection (SyLND) at the time of interval debulking surgery (IDS) for advanced epithelial ovarian cancer (AEOC).

Methods

Systematic literature review of studies including AEOC patients undergoing SyLND versus selective lymph node dissection (SeLND) or no lymph node dissection (NoLND) after neoadjuvant chemotherapy (NACT). Primary endpoints included progression-free survival (PFS) and overall survival (OS). Secondary endpoints included severe postoperative complications, lymphocele, lymphedema, blood loss, blood transfusions, operative time, and hospital stay.

Results

Nine retrospective studies met the eligibility criteria, involving a total of 1,660 patients: 827 (49.8%) SyLND, 490 (29.5%) SeLND, and 343 (20.7%) NoLND. The pooled estimated hazard ratios (HR) for PFS and OS were, respectively, 0.88 (95% confidence interval [CI]=0.65–1.20; p=0.43) and 0.80 (95% CI=0.50–1.30; p=0.37). The pooled estimated odds ratios (ORs) for severe postoperative complications, lymphocele, lymphedema, and blood transfusions were, respectively, 1.83 (95% CI=1.19–2.82; p=0.006), 3.38 (95% CI=1.71–6.70; p<0.001), 7.23 (95% CI=3.40–15.36; p<0.0001), and 1.22 (95% CI=0.50–2.96; p=0.67).

Conclusion

Despite the heterogeneity in the study designs, SyLND after NACT failed to demonstrate a significant improvement in PFS and OS and resulted in a higher risk of severe postoperative complications.

Trial Registration

PROSPERO Identifier: CRD42022303577

Systematic lymph node dissection (SyLND) during interval debulking surgery (IDS) for advanced epithelial ovarian cancer failed to demonstrate a significant improvement in survival rates. The risk of postoperative complications was higher when SyLND was performed. The role of imaging for nodal evaluation after neoadjuvant chemotherapy remains a matter of debate. Further high-quality evidence is required before definitively omitting SyLND during IDS.

Prognostic value of systematic lymphadenectomy in patients with ovarian cancer: A systematic review and meta-analysis

OBJECTIVE

To appraise clinical outcomes of systematic lymphadenectomy in women with ovarian cancer based on stage, control group and type of chemotherapy.

STUDY DESIGN

A literature search was conducted on SCOPUS, PUBMED, COCHRANE, MEDLINE, and WEB OF SCIENCE databases. All comparative studies that assess outcomes of systematic lymphadenectomy in patients with ovarian cancer were eligible. Overall survival was analyzed by pooling log hazard ratio (HR) and standard error of multivariable Cox regression models. MOGGE Meta-analysis Matrix is a novel illustration tool that was used to demonstrate multiple subgroup analyses of included studies.

RESULTS

Twenty-two studies were eligible. Systematic lymphadenectomy was associated with better overall survival, that was close to significance, compared to control group (HR 0.93, 95 %CI 0.86-1.00). Among women treated with adjuvant chemotherapy, overall survival improved in women with stage IIB-IV who underwent systematic lymphadenectomy (HR 0.91, 95 %CI 0.84-0.99) and was most significant among patients with stage III to IV (HR 0.85, 95 %CI 0.73-0.99). Systematic lymphadenectomy did not improve survival in women who received neoadjuvant chemotherapy (HR 0.97, 95 %CI 0.73-1.29). Systematic lymphadenectomy was associated with improved progress-free survival compared to control group (HR 0.88, 95 %CI 0.79-0.99).

CONCLUSION

Although data from clinical trials do not support role of systematic lymphadenectomy in advanced ovarian cancer, overall data conveys stage-specific survival benefit. Further clinical trials may be warranted to assess substage survival outcomes in women with advanced stages.

Lymphadenectomy for primary ovarian cancer: a systematic review and meta-analysis

Objective

To assess the effectiveness of lymphadenectomy at primary debulking surgery (PDS) on the survival of patients with epithelial ovarian cancer (EOC).

Methods

We searched PubMed, Ichushi, and the Cochrane Library. Randomized controlled trials (RCTs) and retrospective cohort studies comparing survival of women with EOC undergoing lymphadenectomy at PDS with that of women without lymphadenectomy were included. We performed a meta-analysis of overall survival (OS), progression-free survival (PFS), and adverse events.

Results

For advanced-stage EOC, 2 RCTs including 1,074 women and 7 cohort studies comprising 3,161 women were evaluated. Meta-analysis revealed that lymphadenectomy was associated with improved OS (hazard ratio [HR]=0.80; 95% confidence interval [CI]=0.70–0.90). However, meta-analysis of 2 RCTs revealed no significant difference in OS between the lymphadenectomy and no-lymphadenectomy groups (OS: HR=1.02; 95% CI=0.85–1.22). For early-stage EOC, 1 RCT comprising 268 women and 4 cohort studies comprising 14,228 women were evaluated. Meta-analysis showed that lymphadenectomy was associated with improved OS (HR=0.75; 95% CI=0.68–0.82). A RCT of early-stage EOC reported that lymphadenectomy was not associated with improved OS (HR=0.85; 95% CI=0.49–1.47). Surgery-related deaths were similar in both groups (risk ratio [RR]=1.00; 95% CI=0.99–1.01); however, blood transfusion was required less frequently in the no-lymphadenectomy group (RR=0.74; 95% CI=0.63–0.86).

Conclusions

Meta-analysis of RCTs and observational studies suggest that lymphadenectomy was associated with improved OS in advanced- and early-stage EOC. However, results from RCTs demonstrate that lymphadenectomy was not associated with improved OS in advanced- and early-stage EOC.

Outcomes of comprehensive lymphadenectomy for patients with advanced stage ovarian carcinoma and rare histologic sub-types

OBJECTIVE

To investigate the prognostic significance of comprehensive lymphadenectomy at the time of primary debulking surgery for patients with rare histologic sub-types of epithelial ovarian carcinoma and clinically advanced stage disease who underwent complete gross resection.

METHODS

The National Cancer Database was accessed and patients diagnosed between January 2010 and December 2015 with stage III-IV clear cell, endometrioid, mucinous, and low-grade serous carcinoma who underwent primary debulking surgery and achieved complete gross resection were identified. Patients who did not undergo lymphadenectomy and those who underwent comprehensive lymphadenectomy (defined as at least 20 lymph nodes removed) were selected for further analysis. Overall survival was compared with the log-rank test and a Cox model was constructed to control for confounders.

RESULTS

A total of 381 patients were identified; 133 (34.9%) patients underwent comprehensive lymphadenectomy while 248 (65.1%) patients did not. There were no differences between the two groups in terms of patient race, age, presence of co-morbidities, type of treatment facility, disease stage, histology, and extent of intra-abdominal disease (p>0.05). There was no difference in overall survival between patients who did and did not undergo comprehensive lymphadenectomy (p=0.42); median overall survival was 51.48 and 47.38 months, respectively. After controlling for patient age, race, insurance status, presence of co-morbidities, intra-abdominal tumor spread, stage and histology, performance of systematic lymphadenectomy was not associated with better survival (HR 0.96, 95% CI 0.69 to 1.35).

CONCLUSION

Comprehensive lymphadenectomy is not associated with a survival benefit for patients with rare histologic sub-types of epithelial ovarian carcinoma and advanced stage disease who underwent primary debulking surgery and complete gross resection.

Role of Lymphadenectomy During Interval Debulking Surgery Performed After Neoadjuvant Chemotherapy in Patients With Advanced Ovarian Cancer

Objective

The role of lymphadenectomy in interval debulking surgery (IDS) performed after neoadjuvant chemotherapy (NACT) in advanced ovarian cancer remains unclear. We aimed to investigate the clinical significance of lymphadenectomy in IDS.

Methods

We retrospectively reviewed and analyzed the data of patients with advanced ovarian cancer who underwent NACT followed by IDS.

Results

In 303 patients receiving NACT-IDS, lymphadenectomy was performed in 127 (41.9%) patients. One hundred and sixty-three (53.8%) patients achieved no gross residual disease (NGRD), and 69 (22.8%) had residual disease < 1 cm, whereas 71 (23.4%) had residual disease ≥ 1cm. No significant difference in progression-free survival (PFS) and overall survival (OS) was observed between the lymphadenectomy group and the no lymphadenectomy group in patients with NGRD, residual disease < 1 cm, and residual disease ≥ 1 cm, respectively. The proportions of pelvic, para-aortic and distant lymph node recurrence were 7.9% (10/127), 4.7% (6/127) and 5.5% (7/127) in the lymphadenectomy group, compared with 5.7% (10/176, P = 0.448), 4.5% (8/176, P = 0.942) and 5.1% (9/176, P = 0.878), respectively, in no lymphadenectomy group. Multivariate analysis identified residual disease ≥ 1 cm [hazard ratios (HR), 4.094; P = 0.008] and elevated CA125 levels after 3 cycles of adjuvant chemotherapy (HR, 2.883; P = 0.004) were negative predictors for OS.

Conclusion

Lymphadenectomy may have no therapeutic value in patients with advanced ovarian cancer underwent NACT-IDS. Our findings may help to better the therapeutic strategy for advanced ovarian cancer. More clinical trials are warranted to further clarify the real role of lymphadenectomy in IDS.

Impact of Lymphadenectomy on Survival of Patients with Serous Advanced Ovarian Cancer After Neoadjuvant Chemotherapy: A French National Multicenter Study (FRANCOGYN)

Background: The population of interest to this study comprised individuals with advanced-stage ovarian carcinoma who were exposed to neoadjuvant chemotherapy (NAC) followed by interval debulking surgery (IDS). Those who had not received systematic lymphadenectomy (SL; Group 1) were compared to those who had received SL (Group 2). Outcome measures included progression-free survival (PFS), overall survival (OS), and surgical complications. Methods: This was a retrospective, multicenter cohort study in nine referral centers of France between January 2000 and June 2017. OS analysis using the multivariate Cox regression model was performed. PFS and surgery-related morbidity were analyzed. Results: Of the 255 patients included, 100 were in Group 1 and 155 in Group 2. Patient majority was, on average, younger and less comorbid, with predominant R0 surgery in Group 2. Dindo–Clavien score was similar between the two groups (p = 0.15). Median OS was 26.8 months in Group 2 and 27.6 months in Group 1. SL was not statistically significant on OS (p = 0.7). Median PFS was 18.3 months in Group 2 and 16.6 months in Group 1. SL had positive impact on PFS (p = 0.005). Conclusions: patients who had received SL (Group 2) had significantly higher PFS regardless of node-positivity status when compared to those who had not received SL (Group 1).

The value of systematic lymphadenectomy during debulking surgery in the treatment of ovarian cancer: a meta-analysis of randomized controlled trials

Background

The therapeutic value of systematic lymphadenectomy during debulking surgery for ovarian cancer remains controversial. We conduct this meta-analysis to evaluate the significance of systematic lymphadenectomy in patients treated with optimal cytoreduction for ovarian cancer.

Method

The PubMed, Medline, Embase, Cochrane Library and Web of Science databases were searched up to October 2019. Only English-language publications of randomized controlled trials (RCTs) that investigated the role of systematic lymphadenectomy in patients with ovarian cancer were selected for this analysis. For overall survival (OS) and progression-free survival (PFS), pooled hazard ratios (HR) with 95% confidence intervals (CIs) were calculated; for complications rate, we calculated pooled risk ratio (RR) with 95% confidence interval (CI). Statistical heterogeneity was assessed using both the I² and chi-square tests. In cases of I² being larger than 50%, a random-effect model was used, otherwise a fixed-effect model was used.

Results

Four RCTs involving 1607 patients were included in the present analysis. There was no difference in OS between systematic lymphadenectomy and unsystematic lymphadenectomy (HR = 1.00; 95% CI = 0.94, 1.07; p = 0.90). Similarly, no significant difference was observed in PFS between these two groups (HR = 0.97; 95% CI = 0.87, 1.08; p = 0.62). And postoperative complications occurred more frequently in the systematic lymphadenectomy group (RR = 1.50; 95% CI = 1.34, 1.68; p < 0.00001).

Conclusion

Systematic lymphadenectomy in patients with optimally cytoreduced ovarian cancer was not associated with longer overall or progression-free survival than unsystematic lymphadenectomy and was associated with a higher incidence of postoperative complications.

Survival Analysis of Lymph Node Resection in Ovarian Cancer: A Population-Based Study

Objective: This study aimed at comprehensively investigating the survival impact of lymphadenectomy during primary surgery in ovarian cancer. Methods: Based on the surveillance, epidemiology, and end results registry (SEER) database, we included ovarian cancer patients with detailed information between 2010 and 2016. Cox regression was performed to select prognostic factors. We conducted propensity score-weighted survival analysis to balance baseline variables, and series of stratified analyses to control main confounding factors. Results: A total of 8,652 patients were ultimately identified. Among 4,360 patients with advanced disease, lymphadenectomy did not show significant survival benefit in general (median overall survival 44 months in non-lymphadenectomy vs. 49 months in lymphadenectomy group, P = 0.055). In subgroup analysis on patients received optimal debulking, lymphadenectomy did not significantly benefit the survival outcome (median overall survival 51, 47, 60, and 58 months in the non-lymphadenectomy, 1-9 lymph nodes, 10-19 lymph nodes, ≥20 lymph nodes groups, respectively, P = 0.287). Consistent results were observed in further stratification analyses. In optimal debulking subgroup, lymph node metastasis indicated worse survival. However, when limited the number of removed lymph nodes to more than 15, there was a marginal statistical difference in overall survival (P = 0.0498) while no significant difference presented in cause-specific survival (P = 0.129) between non-lymphadenectomy, pathological negative lymph node group and positive lymph node group. And the regions of lymph metastasis were also not significantly associate with survival (P = 0.123). Among 3,266 (75%) patients with apparent early-stage disease received lymphadenectomy, 7.75% of whom were reported isolated lymph nodes metastasis and have a poorer survival (P < 0.05). Conclusions: In primary debulking for patients with advanced ovarian cancer, lymphadenectomy was not associated with more favorable outcomes when compared to no lymphadenectomy. The value of lymphadenectomy lies more in staging for apparent early disease rather than therapeutic benefit.

Prognostic value of lymph nodes ratio in patients with stage III ovarian clear cell carcinoma: A retrospective study of patients in Southwest China

Background: Ovarian clear cell carcinoma (OCCC) has a worse prognosis compared to other histological subtypes. Although the survival effect of lymph nodes ratio (LNR) on ovarian carcinoma have been elucidated in several studies, the prognostic effect of LNR in OCCC has not been separately studied. This study aimed to investigate the prognostic significance of LNR in FIGO stage III OCCC.

Methods: Patients with FIGO stage III OCCC who underwent primary cytoreductive surgery and systematic lymphadenectomy from January 2008 to June 2014 in two independent hospitals were retrospectively reviewed. Two independent patients cohorts were used to investigate the survival impact of LNR by using Kaplan-Meier and Cox regression proportional hazard method.

Results: In training cohort, the 5-year progression-free survival (PFS) rates was 32.4% for patients with LNR ≤ 25%, and 19.8% for patients with LNR > 25%, respectively (p = 0.017). The 5-year overall survival (OS) rates was 41.3% for patients with LNR ≤ 25%, and 25.8% for patients with LNR > 25%, respectively (p = 0.003). In multivariate analysis, increased LNR was correlated with a poorer DFS (HR = 2.12 ,95% CI 1.32-3.41, p = 0.002) and OS (HR = 2.29, 95% CI 1.37-5.12, p = 0.001). These results were verified in a validation cohort.

Conclusions: LNR is an independent survival predictor in patients with FIGO stage III OCCC.

Correlation Between Pelvic Peritoneal Disease and Nodal Metastasis in Advanced Ovarian Cancer: Can Intraoperative Findings Define the Need for Systematic Nodal Dissection?

To explore the relationship of peritoneal, and rectal involvement with lymph nodal metastases to identify clinical parameters to guide systematic nodal dissection in advanced ovarian cancer (stage 3c). It is a retrospective study of stage III C epithelial ovarian cancers undergoing cytoreductive surgery with systematic nodal dissection, from January 2011 to December 2016. LS3 score is a cumulative score given for the presence of size 3 lesion (peritoneal disease measuring more than 5 cm) in regions 5, 6, and 7. The depth of rectal involvement was assigned progressive numerical values from 1 (for serosa) to maximum 4 (for mucosa) to generate rectal involvement score. There were 91 patients. 48.35% patients had LS3 lesions in regions 5, 6, 7. Of these, 36% (27/44) had positive nodes. Of the 41 node-positive cases, 43.9% had single and 34.14% had two station involvements. Rectum was involved in 47 patients (51.64%), serosal involvement being the most common type (50.57%). Twenty patients had positive mesorectal nodes (42.55%). The presence of rectal involvement was influenced by the Peritoneal Carcinomatosis Index (PCI) score, the presence of LS3 in lower quadrants (p = 0.008), and LSE score of lower quadrants (p = 0.003). With the increasing depth of rectal infiltration, mesorectal positivity increased significantly (p = 0.000). In multivariate analysis, lower quadrant (regions 5, 6, 7) PCI, LS3 in lower quadrants, LS3 score, rectal involvement score, and the total number of lines of chemotherapy significantly affected different nodal disease parameters. In advanced ovarian cancer, LS3 disease in regions 5, 6, and 7 and rectal involvement directly impact the nodal metastasis and hence mandates a systematic nodal dissection. Mesorectal nodal involvement significantly increases with the increasing depth of rectal involvement necessitating systematic mesorectal nodal clearance for all rectal resections.

Association of lymphadenectomy and survival in epithelial ovarian cancer

PURPOSE

Lymph node metastasis has a significant contribution to the prognosis of epithelial ovarian cancer but the role of lymph node dissection in treatment is not clear. In this study, we aimed to retrospectively determine the effect of the number and localization of lymph nodes removed and the number of metastatic lymph nodes on survival.

METHODS

In this study, we retrospectively reviewed the data of 378 patients (210 patients with lymph node dissection and 168 patients with no dissection) who underwent primary surgery between 2004 and 2014 in various centers with epithelial ovarian cancer diagnosis and followed up in our medical oncology clinic. Demographic and histopathologic features, stage, Ca 125 levels, chemotherapy responses of these patients were examined and survival analyzes were performed.

RESULTS

The median age of the patients was 52 years (range 16-89) and median follow-up duration was 39 months (range 1-146). During the analysis, 156 patients (41%) died and 222 patients (59%) were alive. Patients who underwent lymphadenectomy had significantly improved progression free survival (PFS) (18 vs 31 months, P < 0.05) and overall survival (OS) (57 vs 92 months, P < 0.05). OS was longer in patients with >10 lymph nodes removed compared to patients with 1-10 lymph nodes removed (P = 0.005). Survival was found to be longer in patients with pelvic and paraaortic lymph node dissection compared to patients with only pelvic lymph node dissection (P < 0.05). Patients in stage I-II had no difference in PFS and OS. Patients in stage III-IV had no difference in PFS but there was a significant difference in OS (P = 0.02).

CONCLUSION

It may be a therapeutic effect of lymphadenectomy in advanced stage ovarian cancer. The number of lymph nodes removed and the removal of the paraaortic lymph nodes may also contribute to the treatment.

Role of systematic lymphadenectomy as part of primary debulking surgery for optimally cytoreduced advanced ovarian cancer: Reappraisal in the era of radical surgery

The prognostic significance of pelvic and para-aortic lymphadenectomy during primary debulking surgery for advanced-stage ovarian cancer remains unclear. This study aimed to evaluate the survival impact of lymph node dissection (LND) in patients treated with optimal cytoreduction for advanced ovarian cancer. Data from 158 consecutive patients with stage IIIC–IV disease who underwent optimal cytoreduction (<1 cm) were obtained via retrospective chart review. Patients were classified into two groups: (1) lymph node sampling (LNS), node count <20; and (2) LND, node count ≥20. Progression-free (PFS) and overall survival (OS) were analyzed using the Kaplan–Meier method. Among the included patients, 96 and 62 patients underwent LND and LNS as primary debulking surgery, respectively. There were no differences in the extent of debulking surgical procedures, including extensive upper abdominal surgery, between the groups. Patients who underwent LND had a marginally significantly improved PFS (P = 0.059) and significantly improved OS (P < 0.001) compared with those who underwent LNS. In a subgroup with negative lymphadenopathy on preoperative computed tomography scans, revealed LND correlated with a better PFS and OS (P = 0.042, 0.001, respectively). Follow-ups of subsequent recurrences observed a significantly lower nodal recurrence rate among patients who underwent LND. A multivariate analysis identified LND as an independent prognostic factor for PFS (hazard ratio [HR], 0.629; 95% confidence interval [CI], 0.400–0.989) and OS (HR, 0.250; 95% CI, 0.137–0.456). In conclusion, systematic LND might have therapeutic value and improve prognosis for patients with optimally cytoreduced advanced ovarian cancer.

Incidence and Impact of Lymph Node Metastases in Advanced Ovarian Cancer: Implications for Surgical Treatment

Background: This study aimed to clarify the impact of node involvement (affected to resected nodes) in optimally cytoreduced (residual tumour ≤1cm) stage IIIC/IV ovarian cancer. Methods: 108 consecutive patients with primary stage IIIC/IV ovarian cancer underwent stage-related surgery and got adjuvant platinum-based chemotherapy. Median follow-up: 53.5 months. All patients got systematic para-aortic and pelvic lymphadenectomy. Clinical parameters were retrospectively evaluated. Patients were stratified into 3 groups to evaluate node affection: 1) no (0%), 2) minor (>0%, ≤50%) >0 and 3) major (>50% of affected nodes). Kaplan-Meier survival curve was used to evaluate the prognostic value. Results: On average, 21.3 pelvic and para-aortic nodes were removed per patient (range 1-60 nodes). Minor nodal involvement (node ratio >0-≤0.5: (59%) was most often detected. Increasing node ratio leads to significant decreased overall survival (p<0.001). Significant best overall survival was associated with minor node involvement (node ratio >0 to ≤0.5). Complete cytoreduction correlated with node affection shows significant best prognostic impact in minor node affection compared to incomplete resection (R>0-≤1cm) independent to nodal status (OS p<0.001). Conclusion: Radical surgery is the main factor of improved overall and tumor free survival. Paraaortal and iliacal lymphadenectomy seems to play an important role for prognostic and therapeutic reasons: Prognostic in accurate staging and therapeutic in case of achieved optimal cytoreduction including lymph nodes with histology proven minor node involvement.

Surgery for advanced epithelial ovarian cancer

Cytoreductive surgery for patients with advanced epithelial ovarian cancer has been practised since the pioneering work of Tom Griffiths in 1975. Further research has demonstrated the prognostic significance of the extent of metastatic disease pre-operatively, and of complete cytoreduction post-operatively. Patients with advanced epithelial ovarian cancer should be referred to high volume cancer units, and managed by multidisciplinary teams. The role of thoracoscopy and resection of intrathoracic disease is presently investigational. In recent years, there has been increasing use of neoadjuvant chemotherapy and interval cytoreductive surgery in patients with poor performance status, which is usually due to large volume ascites and/or large pleural effusions. Neoadjuvant chemotherapy reduces the post-operative morbidity, but if the tumour responds well to the chemotherapy, the inflammatory response makes the surgery more difficult. Post-operative morbidity is generally tolerable, but increases in older patients, and in those having multiple, aggressive surgical procedures, such as bowel resection or diaphragmatic stripping. Primary cytoreductive surgery should be regarded as the gold standard for most patients until a test is developed which would allow the prediction of platinum resistance pre-operatively.

The Use of “Optimal Cytoreduction” Nomenclature in Ovarian Cancer Literature: Can We Move Toward a More Optimal Classification System?

Objectives

The objective of this study is to explore how cytoreductive surgical outcomes such as residual disease (RD) and use of the term “optimal cytoreduction” (OCR) have changed over time in the ovarian cancer literature.

Methods

We identified all English-language publications referring to ovarian cancer cytoreduction for a 12-year period. Publications were evaluated for how the diameter of RD was categorized and whether OCR was defined. In addition, the use of RD and OCR terminology trends over time and associations between terminology and the region of corresponding author, study type, and journal impact factor were explored.

Results

Of the 772 publications meeting inclusion criteria, the RD stratification points used to demarcate patient groups were as follows: 0 mm (45%), 5 mm (3.6%), 10 mm (65%), and 20 mm (24%). The use of 0-mm RD (odds ratio [OR], 1.1; 95% confidence interval, 1.05–1.15) and 10-mm RD (OR, 1.1; 95% confidence interval, 1.09–1.20) to delineate patient outcomes increased over time. The use of OCR terminology did not change over time but was more commonly used in clinical studies as well as those from North America. Many studies (70%) defined OCR as less than or equal to 10-mm RD, whereas 30% defined OCR differently or not at all.

Conclusions

Optimal cytoreduction terminology remains ambiguous and inconsistently used in the ovarian cancer surgical literature. On the basis of this literature review, we propose a novel classification system to categorize RD without reference to OCR while accurately and succinctly identifying meaningful clinical subgroups and minimizing bias.

The effect of lymphadenectomy on survival and recurrence in patients with ovarian cancer: a systematic review and meta-analysis

OBJECTIVE

Our objective was to perform a meta-analysis examining the effectiveness of lymphadenectomy in patients with ovarian cancer.

METHODS

PubMed and CENTRAL databases were searched on 15 November 2015 using the terms 'lymphadenectomy', 'ovarian cancer', 'dissection', 'para-aortic', 'pelvic' and survival. Prospective and retrospective studies comparing the outcomes of surgery with or without lymphadenectomy were included. Outcomes were 5-year overall survival, progression-free survival and recurrence rate.

RESULTS

Of the 556 studies identified, 3 randomized controlled trials and 11 retrospective studies were included. Lymphadenectomy was associated with greater 5-year overall survival than no lymphadenectomy (pooled odds ratio = 1.58, 95% confidence interval: 1.41-1.77, p < 0.001). There was no difference in progression-free survival between the groups (pooled overall survival = 1.62, 95% confidence interval: 0.82-3.21, p = 0.168). Lymphadenectomy was associated with greater progression-free survival in randomized clinical trials (pooled overall survival = 1.57, 95% confidence interval: 1.11-2.21, p = 0.010), but not in retrospective studies. Lymphadenectomy was associated with a significantly lower recurrence rate (pooled overall survival = 0.51, 95% confidence interval: 0.30-0.85, p = 0.011). Lymphadenectomy was associated with greater 5-year overall survival in patients with both early and advanced stage cancer, but was associated with greater progression-free survival and lower recurrence rate only in patients with advanced stage cancer.

CONCLUSION

Lymphadenectomy is associated with greater 5-year overall survival in patients with early and advanced stage ovarian cancer, but an effect on progression-free survival and recurrence rate was only found in patients with advanced stage ovarian cancer.

Use of TachoSil® to Prevent Symptomatic Lymphocele after an Aggressive Tumor Debulking with Lymphadenectomy for Advanced Stage Ovarian Cancer. A Pilot Study

OBJECTIVE

To describe the incidence of symptomatic lymphocele (SLC) after an aggressive tumor debulking surgery and lymphadenectomy in patients with ovarian cancer and peritoneal carcinomatosis with or without TachoSil®.

MATERIAL AND METHODS

A pilot retrospective comparative observational study was performed between patients with advanced ovarian cancer International Federation of Gynecology and Obstetrics stages III-IV who underwent complete debulking surgery and radical retroperitoneal lymphadenectomy. In 18 patients, 4 TachoSil® patches were placed in the retroperitoneal area, since January 2014-October 2014. This group was compared with other 18 consecutive patients matched by age, International Federation of Gynecology and Obstetrics stage, surgical complexity, American Society of Anesthesiologists score, comorbidity, and BMI without the use of TachoSil®.

RESULTS

Baseline characteristics were similar between groups. There were no statistically significant differences in terms of surgical complexity, surgical time, estimated blood loss, node removed, length of hospital stay, and complications between groups. SLC was diagnosed in 7 patients (38.8%) without TachoSil®, and in 2 patients (11.1%) with TachoSil® (p = 0.121). The use of TachoSil® was associated with a statistically significant lower re-admission rate (p = 0.041) and with a significantly shorter time to adjuvant chemotherapy (p = 0.02).

CONCLUSIONS

Using TachoSil® in women with advanced stage ovarian cancer who underwent radical debulking with retroperitoneal lymph node dissection is associated with a non-statistically significant reduction in the incidence of SLC. A larger-scale randomized controlled study should be conducted to confirm our preliminary results.

"The impact of debulking surgery in patients with node-positive epithelial ovarian cancer: Analysis of prognostic factors related to overall survival and progression-free survival after an extended long-term follow-up period"

OBJECTIVE

to estimate the prognostic factors associated with survival and progression free survival (PFS) in patients with node-positive epithelial ovarian cancer (EOC) after an extended long-term follow-up period.

METHODS

Data was provided by the Tumor Registry of the Mayo Clinic, Scottsdale, Arizona on 116 node-positive EOC patients who underwent primary cytoreductive surgery observed over the period 1996-2014.

RESULTS

At censoring date, 21 patients were alive (18%), 95 dead (82%), 18 without evidence of disease (NED) (15 alive, 3 dead) and 76 with evidence of disease (ED) (2 alive, 74 dead). Twenty-nine ED patients (38.2%) experienced a recurrence within 2 years, 53 patients (69.7%) before 5 years. No recurrences were recorded after 10 years. The median follow-up in alive patients was 169.8 months (1.20-207.9 months), 34.9 months (0.30-196.2 months) in dead patients, 128.4 months for NED patients (72.8-202.5 months) and 34.6 months (0.1-106.9 months) in ED patients. Multivariate analysis showed an increased risk of dead in patients with age ≥ 60 years (HR: 3.20; p < 0.002), stage IVA/B (compared with stage IIIA1/2, HR: 4.31; p < 0.001 and stage IIIB/C, HR: 5.31; p < 0.010) and incomplete surgery (compared with complete surgery, HR: 3.10; 95% CI, 1.41-6.77; p < 0.003) and a decreased PFS in stage IVA/B (compared with stages IIIB/C; p = 0.003 and stage IIIA; p = 0.000) and residual volume after surgery >0.6 cm (compared with residual disease <0.5 cm; p < 0.023).

CONCLUSIONS

prognostic factors for an extended long-term PFS are similar as those for survival, because after 17-year follow-up period, the majority of alive patients are NED patients.

Clinical significance of systematic retroperitoneal lymphadenectomy during interval debulking surgery in advanced ovarian cancer patients

Objective

To investigate the clinical significance of systematic retroperitoneal lymphadenectomy during interval debulking surgery (IDS) in advanced epithelial ovarian cancer (EOC) patients.

Methods

We retrospectively reviewed the medical records of 124 advanced EOC patients and analyzed the details of neoadjuvant chemotherapy (NACT), IDS, postoperative treatment, and prognoses.

Results

Following IDS, 98 patients had no gross residual disease (NGRD), 15 had residual disease sized <1 cm (optimal), and 11 had residual disease sized ≥1 cm (suboptimal). Two-year overall survival (OS) and progression-free survival (PFS) rates were 88.8% and 39.8% in the NGRD group, 40.0% and 13.3% in the optimal group (p<0.001 vs. NGRD for both), and 36.3% and 0% in the suboptimal group, respectively. Five-year OS and 2-year PFS rates were 62% and 56.1% in the lymph node-negative (LN-) group and 26.2% and 24.5% in the lymph node-positive (LN+) group (p=0.0033 and p=0.0024 vs. LN-, respectively). Furthermore, survival in the LN+ group, despite surgical removal of positive nodes, was the same as that in the unknown LN status group, in which lymphadenectomy was not performed (p=0.616 and p=0.895, respectively). Multivariate analysis identified gross residual tumor during IDS (hazard ratio, 3.68; 95% confidence interval, 1.31 to 10.33 vs. NGRD) as the only independent predictor of poor OS.

Conclusion

NGRD after IDS improved prognosis in advanced EOC patients treated with NACT-IDS. However, while systematic retroperitoneal lymphadenectomy during IDS may predict outcome, it does not confer therapeutic benefits.

The prognostic relevance of node metastases in optimally cytoreduced advanced ovarian cancer

PURPOSE

To delineate the relevance of pelvic and para-aortic node involvement in optimally cytoreduced (residual tumour <1 cm) stage IIIC ovarian cancer patients.

METHODS

Ninety-five consecutive optimally cytoreduced (R ≤ 1 cm) patients with primary stage IIIc ovarian cancer underwent stage-related surgery and got adjuvant platinum-based chemotherapy. Median follow-up: 53.5 months. All patients got systematic lymphadenectomy. On average, 24.7 pelvic and para-aortic lymph nodes were removed per patient (range 1-60 nodes). Patients were stratified into three groups to evaluate node involvement (ratio: affected to resected nodes): (1) (=0); (2) (>0-≤ 0.5) >0 and ≤ 50 % of affected nodes; (3) (>0.5-≤ 1) >50 % of affected nodes. Clinical parameters were retrospectively evaluated. Kaplan-Meier survival curve was used to evaluate the prognostic value.

RESULTS

Most often serous histology, histologic grade 3 and a node ratio >0-≤ 0.5 (61.1 %) were detected. Complete cytoreduction (R = 0 mm) has significant best prognostic impact compared to R > 0 mm-1 cm (OS: p = 0.047, PFS: p = 0.00). Node involvement was associated with serous histology and grade 3. Increasing node ratio leads to significant decreased OS (p = 0.019) and significant best OS was associated with node ratio >0-≤0.5.

CONCLUSIONS

The goal is optimal cytoreduction in advanced ovarian cancer. More extensive lymphadenectomy seems to play an important role in providing an accurate staging, and the node ratio might give prognostic information. Current prospective studies like the LION study (AGO-Ovar) had to investigate if these data have therapeutic implications and may be considered in future staging.

Correlation between the extent of intraperitoneal disease and nodal metastasis in node-positive ovarian cancer patients

AIMS

To investigate correlations between extent of disease (ED), frequency and location of nodal metastases in node-positive EOC patients.

METHODS

Data were collected from 116 consecutive patients who underwent systematic lymphadenectomy during primary surgery. Patients were grouped in ED1 (disease confined in pelvis), ED2 (disease extended to abdomen), and ED3 (distant metastases). Univariate and multivariate analysis were performed for overall survival and progression-free survival (PFS).

RESULTS

Correspondence analysis revealed associations between ED1 and negative nodes, ED2 and positive aortic/pelvic nodes, and ED3 and positive external and common iliac nodes. The most representative group for nodal metastases in ED1 was aortic nodes (77.8%). The number of positive pelvic nodes increased with ED; the RR was 0.58 for ED2 and 0.25 for ED3 (p = 0.004). The RR for positive external iliac nodes was 0.66 in ED2 and 0.31 in ED3 (p = 0.002); the RR for positive common iliac nodes was 0.76 and 0.17, respectively (p = 0.001). Multivariate analysis revealed that aortic nodal metastasis was associated with PFS (p = 0.03; HR, 1.95).

CONCLUSION

Distribution and percentage of nodal metastases varied with ED. The risk of pelvic nodal metastasis, increased with ED. Location of positive nodes was correlated with PFS.

Defining the optimal lymphadenectomy cut-off value in epithelial ovarian cancer staging surgery utilizing a mathematical model of validation

OBJECTIVE

Since 1985 International Federation of Gynecology and Obstetrics includes pelvic and aortic lymphadenectomy as part of the surgical staging in epithelial ovarian cancer (EOC). There is no consensus on the overall number of nodes needed in a systematic lymphadenectomy. The aim of this study is to calculate the optimal cut-off value using a mathematical modeling approach.

METHODS

Data was collected retrospectively, from 1996 to 2000, of 120 consecutive Mayo Clinic patients with EOC and positive nodes. All patients was underwent pelvic and/or aortic lymphadnectomy during surgical staging. To mathematically predict the probability of a positive node in EOC patients we used a predictive mathematical model (PMM). The mathematical analysis consisted: creation of a new PMM according to our purposes, application of PMM to describe the experimental data in order to build the polynomial regression curves in each lymphatic area and determine the optimal point for each curve.

RESULTS

The mean number of lymph nodes and metastatic nodes removed were 35 and 7.8, respectively; the mean percentage of positive nodes was 28.3%. The optimal point of each fitting curves were: 7 nodes for unilateral aortic nodal sampling (at least 3 infrarenal or 5 inframesenteric) and 15 nodes for unilateral pelvic lymphadenectomy (at least 5 external iliac).

CONCLUSIONS

We can mathematically predict the probability to obtain a positive node in EOC surgical staging. Our results have shown the need to obtain at least 22 lymph nodes between pelvic and aortic lymphadenectomy.