Predictive factors for lymph node metastases in vulvar cancer. An analysis of the AGO-CaRE-1 multicenter study

Background: Lymph node (LN) metastasis is the most important prognostic factor in primary vulvar cancer. Assessing risk factors for the incidence and extent of LN metastases may help to select the optimal treatment strategy for each individual patient. Methods: In a subgroup analysis of the large multicenter AGO-CaRE-1 study we included all patients treated with radical groin dissection. Univariate and multivariate regression analyses were performed in order to detect factors associated with the prevalence and extent of nodal involvement. Results: In total, 1162 patients were analyzed. Univariate analyses detected age, ECOG as well as multiple tumor characteristics such as FIGO stage, grading, depth of invasion, tumor diameter, and (lymph)vascular space invasion to be related with the prevalence of LN metastases. Interestingly, only tumor stage, tumor diameter and depth of infiltration were found to be significantly associated with the number of LN metastases. In multivariate analysis, age (OR 1.03), lymphvascular space invasion (OR 4.97), tumor stage (OR 2.22) and depth of infiltration (OR 1.08) showed an association with the prevalence of LN metastases. Regarding the number of metastatic LNs, only tumor stage (OR 2.21) or, if excluded, tumor diameter (OR 1.02) were tested significant. Conclusion: This large analysis of the multicenter AGO-CaRE-1-study identified lymphvascular space invasion, tumor stage, and depth of infiltration as factors with the strongest association regarding the prevalence of LN metastasis. Interestingly, tumor stage or, if excluded, tumor diameter were the only factors associated with the prevalence as well as the extent of LN metastases.