Systemic Immune Inflammation Index and T-Staging Predict Prognosis in Patients with Muscle-Invasive Bladder Cancer

To explore the effect of combining the preoperative systemic immune inflammation index (SII) and T-staging to predict the prognosis of patients with muscle-invasive bladder cancer (MIBC).

The clinical data of 94 MIBC patients who met the inclusion criteria of our hospital from September 01, 2012, to August 31, 2022, were collected. Data included sex, age, smoking history, tumour size, tumour number, pathology, P-grading, T-staging, SII, and overall survival (OS). The optimal cut-off of SII (863.62) was selected by obtaining the receiver operating characteristic (ROC) curve. Then, the samples were divided into the low-SII group (SII <863.62, 51 cases) and the high-SII group (SII ≥863.62, 43 cases). T-staging could be divided into T2 (61 cases) and T3 and higher stages (33 cases) according to the findings on depth of tumour invasion. Furthermore, the role of combined SII and T-staging for prognosis prediction was evaluated by performing Kaplan-Meier survival analysis and Cox proportional hazards modelling in the OS analysis.

MIBC patients with higher SII (≥863.62) were associated with shorter OS (p = 0.00005). Patients with more advanced T-stages had shorter OS than those with early T-stages (p = 0.00006). Furthermore, patients who had both higher SII and more advanced T-stages had markedly shorter OS (p = 0.00001).

In patients with MIBC, a higher SII and increasing T-stage indicate a worse prognosis and shorter OS. Therefore, the combined SII and T staging approach is a reliable prognostic predictor for patients with MIBC.