Risk Classification of Bladder Cancer by Gene Expression and Molecular Subtype

Predicting individual outcomes after radical cystectomy in urothelial variants with Cancer of the Bladder Risk Assessment (COBRA) score

OBJECTIVE

To validate the Cancer of the Bladder Risk Assessment (COBRA) score in patients with urothelial variants.

METHODS

Epidemiological, clinical, radiological, and anatomopathological data were collected from patients with urothelial carcinoma who underwent radical cystectomy at the Institute of Cancer of São Paulo between May 2008 and December 2022. Patients with the presence of at least 10% of any urothelial variants in the radical cystectomy specimens' anatomopathological exam were included in the study. The COBRA score and derivatives were applied and correlated with oncological outcomes.

RESULTS

A total of 680 patients [482 men (70.9%) and 198 women (29.1%)]; 66 years (IQR 59-73) underwent radical cystectomy for bladder tumor, and of these patients, a total of 167 patients presented any type of urothelial variant. The median follow-up time was 28.77 months (IQR 12-85). The three most prevalent UV were squamous differentiation (50.8%), glandular differentiation (31.3%), and micropapillary differentiation (11.3%). The subtypes with the worst prognosis were sarcomatoid with a median survival of 8 months (HR 1.161; 95% CI 0.555-2.432) and plasmacytoid with 14 months (HR 1.466; 95% CI 0.528-4.070). The COBRA score for patients with micropapillary variants demonstrated good predictive accuracy for OS (log-rank P = 0.009; 95% IC 6.78-29.21) and CSS (log-rank P = 0.002; 95% IC 13.06-26.93).

CONCLUSIONS

In our study, the COBRA score proved an effective risk stratification tool for urothelial histological variants, especially for the micropapillary urothelial variant. It may be helpful in the prognosis evaluation of UV patients after radical cystectomy.

Advances in diagnosis and treatment of bladder cancer

Bladder cancer remains a leading cause of cancer death worldwide and is associated with substantial impacts on patient quality of life, morbidity, mortality, and cost to the healthcare system. Gross hematuria frequently precedes the diagnosis of bladder cancer. Non-muscle-invasive bladder cancer (NMIBC) is managed initially with transurethral resection of a bladder tumor (TURBT), followed by a risk stratified approach to adjuvant intravesical therapy (IVe), and is associated with an overall survival of 90%. However, cure rates remain lower for muscle invasive bladder cancer (MIBC) owing to a variety of factors. NMIBC and MIBC groupings are heterogeneous and have unique pathological and molecular characteristics. Indeed, The Cancer Genome Atlas project identified genetic drivers and luminal and basal molecular subtypes of MIBC with distinct treatment responses. For NMIBC, IVe immunotherapy (primarily BCG) is the gold standard treatment for high grade and high risk NMIBC to reduce or prevent both recurrence and progression after initial TURBT; novel trials incorporate immune checkpoint inhibitors. IVe gene therapy and combination IVe chemotherapy have recently been completed, with promising results. For localized MIBC, essential goals are improving care and reducing morbidity following cystectomy or bladder preserving strategies. In metastatic disease, advances in understanding of the genomic landscape and tumor microenvironment have led to the implementation of immune checkpoint inhibitors, targeted treatments, and antibody-drug conjugates. Defining better selection criteria to identify the patients most likely to benefit from a specific treatment is an urgent need.

Do Histology and Primary Tumor Location Influence Metastatic Patterns in Bladder Cancer?

Metastasis is the leading cause of death in patients with bladder cancer. This study utilized a statistical analysis of patient data from the Surveillance, Epidemiology, and End Results database to examine the influence of histological type and primary site on the metastatic behavior of bladder cancer. Significantly different metastatic patterns were observed among bladder cancer patients depending on their histological type. Patients with squamous cell carcinoma showed a significantly (p < 0.001) lower bone metastasis rate (27.2%) than patients with urothelial carcinoma (UC) (38.3%). Patients with neuroendocrine carcinoma showed a significantly (p < 0.001) higher liver metastasis rate (52.1%) and a significantly (p = 0.001) lower lung metastasis rate (25.7%) than patients with UC (22.6% and 33.5%, respectively). UC patients also demonstrated differences in metastatic behavior according to histological subtype. The sarcomatoid subtype showed a significantly (p < 0.001) higher lung metastasis rate (51.6%) and a significantly lower (p = 0.002) lymph node metastasis rate (22.6%) than the micropapillary subtype (12.1% and 54.1%, respectively). Significant differences in metastatic behavior were also observed among patients with conventional UCs originating from the bladder, ureter, and renal pelvis. This study highlights the impact of histological characteristics and primary site on metastatic tendencies in bladder cancer, highlighting the importance of tailoring treatment and surveillance strategies.

Pesticides and Bladder Cancer: Mechanisms Leading to Anti-Cancer Drug Chemoresistance and New Chemosensitization Strategies

Multiple risk factors have been associated with bladder cancer. This review focuses on pesticide exposure, as it is not currently known whether agricultural products have a direct or indirect effect on bladder cancer, despite recent reports demonstrating a strong correlation. While it is known that pesticide exposure is associated with an increased risk of bladder cancer in humans and dogs, the mechanism(s) by which specific pesticides cause bladder cancer initiation or progression is unknown. In this narrative review, we discuss what is currently known about pesticide exposure and the link to bladder cancer. This review highlights multiple pathways modulated by pesticide exposure with direct links to bladder cancer oncogenesis/metastasis (MMP-2, TGF-β, STAT3) and chemoresistance (drug efflux, DNA repair, and apoptosis resistance) and potential therapeutic tactics to counter these pesticide-induced affects.