Neutrophil-to-lymphocyte ratio is a potential prognostic biomarker for extramammary Paget disease: A retrospective study

The neutrophil-to-lymphocyte ratio (NLR) is a useful prognostic biomarker for many cancer types. However, the prognostic value of NLR in patients with extramammary Paget disease (EMPD) remains unclear. This study aimed to determine whether NLR is associated with overall survival (OS) in patients with EMPD. In this single-center retrospective case series, we analyzed data of 109 patients with previously untreated EMPD who presented to our hospital. Data on age, sex, primary tumor site, invasion level, presence of lymph node and distant metastases, baseline NLR, and OS were analyzed. The enrolled patients were classified into the metastatic or non-metastatic EMPD groups. The metastatic EMPD group had higher invasion level and NLR value (p < 0.001 and p = 0.005, respectively) compared with the non-metastatic EMPD group. Cox proportional hazards model analysis showed invasion level (p = 0.0093) and NLR value (p = 0.019) to be independent prognostic factors for OS. Notably, multivariate analysis revealed that invasion level (p = 0.045) and NLR value (p = 0.036) were independent prognostic factors for OS in the metastatic EMPD group. The limitations of this study include the small number of participants and its retrospective nature. In conclusion, since NLR can be routinely assessed with high feasibility, it might be a useful biomarker for predicting prognosis in patients with EMPD.