Systemic immune‐inflammation index and pan‐immune value as prognostic indicators of clinical outcomes in mycosis fungoides: A retrospective cohort study

Blood inflammatory markers may provide prognostic insights but remain underexplored in mycosis fungoides (MF). To evaluate the prognostic significance of baseline blood inflammatory markers, including the neutrophil-to-lymphocyte ratio (NLR), eosinophil-to-lymphocyte ratio (ELR), monocyte-to-lymphocyte ratio (MLR), pan-inflammation value (PIV) and systemic immune-inflammation index (SII), in MF. This retrospective cohort study included MF patients diagnosed between 1997 and 2024 at a tertiary medical centre. Markers were analysed in relation to MF stage, morphology, overall survival (OS) and progression-free survival (PFS). Among 195 patients, all markers were significantly elevated in advanced-stage MF compared to early-stage MF. Marker levels generally increased from patch to tumour-stage MF but did not distinguish erythrodermic MF from tumour MF. All markers were associated with poor survival outcomes in univariable analysis. However, in multivariable analysis, only PIV and SII independently associated with poor OS and PFS. Patients with high PIV or SII were more likely to exhibit poor prognostic factors, including advanced stage, head and neck involvement and elevated serum lactate dehydrogenase levels, and experienced more frequent disease progression during follow-up. Single-centre retrospective design. Baseline PIV and SII can be significant prognostic markers in MF, offering enhanced risk stratification and guiding clinical management.