A nomogram incorporating PD-L1, NLR, and clinicopathologic features to predict inguinal lymph node metastasis in penile squamous cell carcinoma.

BACKGROUND

Accurate preoperative prediction of inguinal lymph node metastasis (LNM) aids in clinical decision making, especially for patients with penile cancer with clinically negative lymph nodes. We aim to develop a nomogram to predict the preoperative risk of LNM by incorporating clinicopathologic features and tumor biomarkers.

METHODS

Eighty-four patients with penile cancer with clinically negative lymph nodes were enrolled. The programmed death ligand 1 (PD-L1) expression profile was detected by immunohistochemistry. The neutrophil-to-lymphocyte ratio (NLR) was calculated based on parameters of a routine blood examination. Multivariate logistic regression analysis was utilized to construct predictive nomograms for LNM based on data of 64 patients. The nomogram performance was assessed for calibration, discrimination, and clinical use.

RESULTS

Tumor grade, lymphovascular invasion, PD-L1, and NLR were independent predictors of LNM. Then, 4 prediction models were constructed. Clinical model included tumor grade and lymphovascular invasion. NLR model was built by adding the NLR to clinical model. PD-L1 model was built by adding the PD-L1 to clinical model. Finally, a combined model was built by adding both PD-L1 and NLR to clinical model. Combined model showed the best performance compared with other models. It showed good discrimination with a C-index of 0.89, and good calibration. In addition, decision curve analysis suggested that model 4 was clinically useful.

CONCLUSIONS

We developed a nomogram that incorporated tumor grade, lymphovascular invasion, PD-L1, and NLR that could be conveniently used to predict the preoperative individualized risk of inguinal LNM in patients with penile cancer.