Molecular classification of urothelial bladder carcinoma

Abstract

Urothelial bladder carcinoma (UC) ranks among the top ten most commonly diagnosed cancers worldwide on an annual basis. The standardized classification system for urothelial bladder tumors is the Tumor, Node, Metastasis classification, which reflects differences between non-muscle-invasive bladder carcinoma (NMIBC) and muscle-invasive bladder carcinoma (MIBC) and it depends on the extent to which tumor has infiltrated the bladder wall and other tissues and organs. NMIBC and MIBC exhibit great intrinsic heterogeneity regarding different prognoses, survival, progression, and treatment outcomes. In recent years, studies based on mRNA expression profiling revealed the existence of biologically relevant molecular subtypes of UC, which show variant molecular features that can provide more precise stratification of UC patients. Here, we present a complex classification of UC based on mRNA expression studies and molecular subtypes of NMIBC and MIBC in detail with regard to different mRNA expression profiles, mutational signatures, and infiltration by non-tumor cells. The possible impact of molecular subtyping on treatment decisions and patients’ outcomes is outlined, too.

Lysine Methyltransferase 9 (KMT9) Is an Actionable Target in Muscle-Invasive Bladder Cancer

“…The primary histological types of BC are urothelial carcinoma, which is the most common type, squamous cell carcinoma, and adenocarcinoma [2]. Urothelial carcinoma can be divided into non-muscle-invasive (NMI) BC and muscle-invasive (MI) BC based on tumor infiltration into the bladder wall [3]. NMIBC, accounting for approximately 75% of newly diagnosed cases, manifests as either an exophytic papillary tumor limited to the mucosa (stage Ta according to the tumor-node-metastasis (TNM) classification) or the lamina propria (T1), or as a flat high-grade lesion (carcinoma in situ (CIS)) [4].…”

The Role of Longevity Assurance Homolog 2/Ceramide Synthase 2 in Bladder Cancer

“…In this classification, the initial stages, denoted as Ta, are found within the mucosa, while T1 encompasses the lamina propria. Progressing from T2 signifies the invasion of muscular tissue, T3 involves the perivesical fat, and T4 extends to other organs and the abdominal cavity (discussed in [6]).…”