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.