Single-cell dissection of multifocal bladder cancer reveals malignant and immune cells variation between primary and recurrence tumor lesions

Bladder carcinoma (BLCA) is characterized by a high rate of post-surgery relapse and multifocality, with multifocal tumors carrying a 40% higher risk of recurrence compared to single tumors. Recurrence is a major contributor to bladder cancer-specific mortality. However, understanding interregional or intraregional malignant heterogeneity and cellular communication within the primary and recurrence tumor microenvironment (TME) remains a significant challenge. Here, we employed single-cell RNA sequencing (scRNA-seq) to analyze separate tumor lesions from five multifocal bladder cancer patients (comprising three primary tumors and two recurrence tumors).