Evaluating the significance of location of lymph node metastasis and extranodal disease in women with stage IIIC endometrial cancer

ObjectiveTo determine the prognostic significance of location of lymph node metastasis and extranodal disease for women with stage IIIC endometrial cancer.MethodsData were extracted from the Surveillance, Epidemiology, and End Results database between 1988 and 2005. Statistical analysis used Chi-square test, Kaplan–Meier method, and Cox proportional hazards model.ResultsA total of 2559 women were identified; 1453 stage IIIC1, and with 906 stage IIIC2 tumors. Compared to stage IIIC1; more stage IIIC2 patients demonstrated high-risk factors such as grade III disease (p < 0.001), unfavorable histologic types (p = 0.01), concurrent disease at other extrauterine sites (p < 0.001), and greater than two positive lymph nodes (p < 0.001). While the 5-year disease specific survival was comparable (p > 0.05) among node positive patients found to have positive peritoneal cytology (44.0%), adnexal/serosal metastasis (42.9%), and vaginal/parametrial involvement (41.8%); it differed individually in all three categories from those with nodal metastasis alone (67.0%, p < 0.001). Among women with extranodal disease, the location of nodal metastasis had no effect on survival (HR = 0.92; 95% CI, 0.74–1.14). For women with node only stage IIIC tumors, those patients with positive para-aortic nodes were more likely to die from their tumors (HR = 1.40; 95% CI, 1.12–1.75).Conclusion(s)Location of lymph node metastasis is prognostic in patients with nodal disease alone, and not in those with extranodal disease. Extranodal disease is associated with a poor prognosis and should be regarded in conjunction with location of lymph node metastasis for risk-stratification in stage IIIC endometrial cancer.

► Extranodal disease is a strong prognostic factor in stage IIIC endometrial cancer.
► Location of nodal metastasis matters only in patients with nodal disease alone.
► Substage classification should include nodal site plus extranodal disease status.