A Clinical Nomogram Predicting Pathologic Lymph-Node Involvement in Esophageal Cancer Patients
*Puja Gaur1, *Boris Sepesi2, *Wayne L Hofstetter1, *Arlene M Correa1, *Manoop S Bhutani1, Jack A Roth1, *Ara A Vaporciyan1, Jeffrey H Peters2, *Thomas J Watson2, Stephen G Swisher1
1UT MD Anderson Cancer Center, Houston, TX;2University of Rochester School of Medicine, Rochester, NY
OBJECTIVE(S): Esophageal cancer patients with pathologic lymph-node involvement (pN1) generally have a poor prognosis with surgery alone. We, therefore, constructed a nomogram to predict the risk of pN1 prior to surgical resection and externally validated the clinical utility of the model.
METHODS: 273 esophageal adenocarcinoma patients treated with surgery alone were reviewed from two different institutions (MDACC=164, training set; URMC=109, validation set). Pretreatment clinical parameters were utilized to construct a nomogram for predicting the risk of pN1. Internal and external validation of the nomogram was performed to assess clinical utility.
RESULTS: Of the 164 patients in the training set, 56 patients (34%) had lymph-node involvement (pN1). Significant factors associated with pN1 on univariable logistic regression analysis (using a p-value of <.05) included endoscopically-determined clinical tumor depth (cT), clinical nodal (cN) status, and clinical tumor length (cL). Multivariable analysis suggested the significant independent factors were cT (OR:5.6, 95%CI:1.7-18.6, p<0.01) and cL>2cm (OR:7.0, 95%CI:2.7-18.1, p<0.001). Regression tree analysis was used to determine the best cutoff for cL. A nomogram was created for pN1 using these clinical parameters and was internally validated by bootstrapping with a predicted accuracy of 85.1%. External validation performed on the validation set demonstrated an original C-index of 0.777 suggesting good clinical utility.
CONCLUSIONS: Our analyses demonstrate that the risk of pathologic nodal involvement in esophageal adencarcinoma patients can be estimated by this clinical nomogram, which will allow the identification of patients at high-risk of harboring positive lymph-nodes who may be candidates for en-bloc resection and/or neoadjuvant treatment.