Prognostic Significance of Cytokeratin 19 and Squamous Cell Cancer Antigen in Histologically Negative Sentinel Lymph Nodes of Cervical Squamous Cell Carcinoma

Objective: The aim of the study was to evaluate the prognostic value of positive cytokeratin 19 (CK19) and squamous cell cancer antigen (SCCAg) expression in histologically negative sentinel lymph nodes after surgery for cervical squamous cell carcinoma. Methods: Immunohistochemistry was performed to detect the expression of CK19 and SCCAg using polyclonal antibody on 149 pair of formalin-fixed, paraffin-embedded cervical squamous cell carcinoma and histologically negative sentinel lymph node tissue samples, and results were compared with data from the prospectively registry of cervical squamous cell carcinoma by univariate and multivariate logistic regression model focusing specifically on recurrence. The survival was assessed by the Kaplan-Meier method and proportional hazards model. Results: Cytokeratin 19 and SCCAg expression in histologically negative sentinel lymph nodes were documented in 15.4% (n = 23) and 20.8% (n = 31) patients and were associated with a higher incidence of tumor progression and poorer disease-free survival (DFS, P < 0.05). Multivariate logistic regression analysis demonstrated that CK19 (P = 0.001) and SCCAg (P = 0.001) expression in histologically negative sentinel lymph nodes, International Federation of Gynecology and Obstetrics staging (P = 0.000), and cervical stroma infiltration depth (P = 0.005) were independent predictive factors for recurrence. The proportional hazards model identified CK19 (P = 0.001) and SCCAg (P = 0.005) expression in histologically negative sentinel lymph nodes, International Federation of Gynecology and Obstetrics staging (P = 0.003), and cervical stroma infiltration depth (P = 0.005), as independently related to DFS. Using subgroup analysis, we found that the CK19+/SCCAg + subgroup has the poorest prognosis, whereas the CK19/SCCAg subgroup has the best prognosis (P = 0.000). Conclusions: Immunohistochemical assessment of both CK19 and SCCAg status in histologically negative sentinel lymph nodes may be a valuable approach for predicting recurrence and survival after curative surgery for cervical squamous cell carcinoma.