The prognostic significance of lymph node ratio in carcinoid tumors

Objectives: Nodal metastases are an important prognostic factor in survival for patientswith carcinoid tumors. However, it is unclear if the current American Joint Committee on Cancer's gastrointestinal carcinoid staging guidelines, which look only at presence or absence of regional metastases (N1/N0), are fully utilizing lymph node data. Some research has indicated that lymph node ratios (LNRs) are powerful predictors of survival. In our study, we evaluated LNR in carcinoid tumors. Methods: Eleven thousand one hundred eighty-nine carcinoid tumors recorded in the Surveillance, Epidemiology, and End Results database between 1988 and 2011 were evaluated. Receiver operating characteristic curves and the area under the receiver operating characteristic curve (AUC) were used to evaluate the ability of nodal involvement or LNR to predict 10-year survival. All analyses were performed using STATA and SAS version 9.3. Results: Receiver operating characteristic curve analysis indicated that LNR and node positivity were both predictive of 10-year survival, AUC = 0.734, P < 0.0001; AUC = 0.7048, P < 0.0001. Lymph node ratio was 88%specific and 50%sensitive in predicting 10-year survival. N1 was 88% specific and 49% sensitive in predicting 10-year survival. Conclusions: Our study indicated that LNR is an independent predictor of survival for patientswith carcinoid tumors but was no better than N1/N0 for 10-year survival.