Triple-marker immunohistochemical assessment of muscle-invasive bladder cancer: Is there prognostic significance?

Identification of Molecular Subgroups of Muscle-Invasive Urothelial Bladder Cancer and Their Impact on Treatment Outcome

PURPOSE

Neoadjuvant chemotherapy (NACT) improves muscle-invasive bladder cancer (MIBC) survival. However, its efficacy is limited to a group of patients. This study explored CK5/6 and GATA3 for molecular subtyping and their prediction to response in patients with MIBC.

METHODS

This is a prospective study that includes 50 patients with TCC bladder. All Patients received 4 cycles neoadjuvant gemcitabine/ cisplatin then guided to further treatment according to the response to NACT. Responders (CR & PR) went for CCRTH whereas non-responders (SD & PD) went surgery if resectable or second line chemotherapy if non-resectable. The baseline TUR pathology specimens were examined for histopathological feature and CK5/6 and GATA3 and divided into 4 molecular subgroups.

RESULTS

The patients were divided into four molecular subgroups: luminal (n=12/26.7%), basal (n=8/17.8%), double-positive (n=21/26.7%), and double-negative (n=4/8.9%). There was no clinicopathological difference seen among the 4 molecular subgroups. The PFS was higher in patients with GATA3 positive (24 months) than GATA3 negative (17 months). Yet, it did not reach a statistically significant value (P = 0.1605). On the other hand, PFS was not affected by either CK5/6 status or different molecular subgroups. The OS was better in the luminal subgroup than the basal (20.8 months versus 16.16 months respectively, While the double positive showed the highest OS of 26 months(P=0.0352).

CONCLUSION

GATA3 and CK5/6 IHC can classify MIBCs into four subtypes. These subtypes predicted treatment outcomes, however, were not correlated with the response to NACT. GATA3-positive tumors, luminal and double-positive subtypes tend to have higher OS and PFS. CK5/6 positivity did not impact the treatment outcome.

Uncovering the epidemiology of bladder cancer in the Arab world: A review of risk factors, molecular mechanisms, and clinical features

Objective

Bladder cancer (BC) is a significant public health concern in the Middle East and North Africa, but the epidemiology and clinicopathology of the disease and contributors to high mortality in this region remain poorly understood. The aim of this systematic review was to investigate the epidemiological features of BC in the Arab world and compare them to those in Western countries in order to improve the management of this disease.

Methods

An extensive electronic search of the PubMed/PMC and Cochrane Library databases was conducted to identify all articles published until May 2022, following the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. A total of 95 articles were included in the final analysis after title, abstract, and full-text screening, with additional data obtained from the GLOBOCAN and WHO 2020 databases.

Results

Most of the included articles were case-control studies examining the risk factors and molecular mechanisms of BC. These studies originated from 10 different countries, with Egypt being the most active contributor. While BC in the Arab world shares some common risk factors with Western countries, such as smoking and occupational exposure, it also exhibits unique features related to schistosomiasis. The high mortality rates in this region are alarming and can be attributed to various factors, including the prevalence of smoking, the impact of schistosomiasis, a combination of genetic and socioeconomic factors, treatment shortages, and limited access to care or inadequate assessment of the quality of care.

Conclusion

Despite the relatively low incidence of BC in Arab countries, the mortality rates are among the highest worldwide. BC tends to be more aggressive in the Arab world, making it essential to implement strategies to address this burden.

Are We Ready to Implement Molecular Subtyping of Bladder Cancer in Clinical Practice? Part 2: Subtypes and Divergent Differentiation

Following several attempts to achieve a molecular stratification of bladder cancer (BC) over the last decade, a "consensus" classification has been recently developed to provide a common base for the molecular classification of bladder cancer (BC), encompassing a six-cluster scheme with distinct prognostic and predictive characteristics. In order to implement molecular subtyping (MS) as a risk stratification tool in routine practice, immunohistochemistry (IHC) has been explored as a readily accessible, relatively inexpensive, standardized surrogate method, achieving promising results in different clinical settings. The second part of this review deals with the pathological and clinical features of the molecular clusters, both in conventional and divergent urothelial carcinoma, with a focus on the role of IHC-based subtyping.