The Significance of Squamous Histology on Clinical Outcomes and PD-L1 Expression in Bladder Cancer

[Oncological relevance of neuro-urological diseases]

Apart from a few exceptions, there is currently little scientific evidence on the oncological relevance of neuro-urological diseases. Most research has been conducted into the association between long-term spinal cord injury with its consequences for the lower urinary tract and the occurrence of bladder cancer. These cancers differ in many ways from bladder cancers in patients without spinal cord injury: patients are 20 years younger on average, tumours are very often already muscle-invasive and poorly differentiated with a high proportion of squamous cell carcinomas, and the prognosis is poor. These characteristics also occur in spinal cord injury patients without permanent catheter drainage of the urinary bladder. Although the pathophysiological association has not been clarified in detail, the presence of a neurogenic bladder appears to be the decisive link between spinal cord injury and the occurrence of bladder cancer. Pathological pressure conditions in the urinary bladder and frequent urinary tract infections or asymptomatic bacteriuria resulting from neurogenic lower urinary tract dysfunction could be the decisive pathophysiological factors. In this respect, urinary bladder cancer in persons with a chronic spinal cord injury represents a model tumour after denervation. The clinically important question of screening requires future interdisciplinary research approaches.

Adjuvant Chemotherapy and Survival After Radical Cystectomy in Histologic Subtype Bladder Cancer

OBJECTIVES

Patients with histologic subtype bladder cancer (HSBC) suffer worse outcomes than those with conventional urothelial carcinoma (UC). We sought to characterize the use of adjuvant chemotherapy (AC) in HSBC after radical cystectomy (RC) using the National Cancer Database (NCDB).

MATERIALS AND METHODS

We retrospectively queried the NCDB (2006-2019) for patients with non-metastatic bladder cancer (BC) who underwent RC (N = 45,797). Patients were stratified by histologic subtype and receipt of AC. Multivariable logistic regression determined associations of demographic and clinicopathologic features with receipt of AC. Multivariable Cox regression evaluated associations between receipt of any AC and overall survival (OS).

RESULTS

We identified 4,469 patients with HSBC classified as squamous, adenocarcinoma, small cell, sarcomatoid, micropapillary, or plasmacytoid. Squamous comprised 31% of the HSBC cohort, followed by small cells and micropapillary. Black patients were presented with a higher prevalence of adenocarcinoma (119/322, 37.0%). Use of AC was highest in plasmacytoid and small cell (30% each) and lowest in squamous (11%). Neuroendocrine histology was independently associated with greater odds of receiving AC (HR 1.6, 95% CI 1.37-1.87), while squamous cell histology was associated with lower odds (HR 0.61, 95% CI 0.53-0.71). On multivariable Cox regression analysis, treatment with AC was associated with significantly longer OS (HR 0.69, 95% CI 0.59-0.81) and for squamous, sarcomatoid, and micropapillary cohorts after stratified by subtype.

CONCLUSIONS

AC was variably used among patients with HSBC and was associated with OS benefit in such patients.

HPV-positive clinically advanced squamous cell carcinoma of the urinary bladder (aBSCC): A comprehensive genomic profiling (CGP) study

BACKGROUND

Advanced bladder squamous cell carcinoma (aBSCC) is an uncommon form of urinary bladder malignancy when compared with the much higher urothelial carcinoma incidence. We studied the genomic alteration (GA) landscape in a series of aBSCC based on the association with human papilloma virus (HPV) to determine if differences in GA would be observed between the positive and negative groups.

METHODS

Using a hybrid capture-based FDA-approved CGP assay, a series of 171 aBSCC were sequenced to evaluate all classes of GA. Tumor mutational burden (TMB) was determined on up to 1.1 Mbp of sequenced DNA and microsatellite instability (MSI) was determined on up to 114 loci. Programmed cell death ligand -1 (PD-L1) expression was determined by IHC (Dako 22C3) with negative expression when PD-L1 was 0, lower expression of positivity set at 1 to 49%, and higher expression set at ≥50% expression.

RESULTS

Overall, 11 (6.4%) of the aBSCC were found to harbor HPV sequences (10 HPV16 and 1 HPV 11). HPV+ status was identified slightly more often in women (NS) and in younger patients (P = 0.04); 2 female patients with aBSCC had a prior history of SCC including 1 anal SCC and 1 vaginal SCC. HPV+ aBSCC had fewer GA/tumor (P < 0.0001), more inactivating mutations in RB1 (P = 0.032), and fewer inactivating GA in CDKN2A (P < 0.0001), CDKN2B (P = 0.05), TERT promoter (P = 0.0004) and TP53 (P < 0.0001). GA in genes associated with urothelial carcinoma including FGFR2 and FGFR3 were similar in both HPV+ and HPV- aBSCC groups. MTAP loss (homozygous deletion) which has emerged as a biomarker for PRMT5 inhibitor-based clinical trials was not identified in any of the 11 HPV+ aBSCC cases, which was significantly lower than the 28% positive frequency of MTAP loss in the HPV- aBSCC group (P < 0.0001). MTOR and PIK3CA pathway GA were not significantly different in the 2 groups. Putative biomarkers associated with immunotherapy (IO) response, including MSI and TMB status, were also similar in the 2 groups. PD-L1 expression data was available for a subset of both HPV+ and HPV- cases and showed high frequencies of positive staining which was not different in the 2 groups.

CONCLUSIONS

HPV+ aBSCC tends to occur more often in younger patients. As reported in other HPV-associated squamous cell carcinomas, HPV+ aBSCC demonstrates significantly reduced frequencies of inactivating mutations in cell cycle regulatory genes with similar GA in MTOR and PIK3CA pathways. The implication of HPV in the pathogenesis of bladder cancer remains unknown but warrants further exploration and clinical validation.

Challenges and opportunities in the management of non-urothelial bladder cancers

Urothelial carcinoma accounts for approximately 90% of all bladder cancer diagnoses. Localized, muscle-invasive disease is often managed with a multidisciplinary approach including either neoadjuvant chemotherapy (NAC) followed by radical cystectomy or concurrent chemoradiation, whereas multiple immunotherapies and novel antibody drug conjugates have recently joined platinum-based chemotherapy as standard of care therapy for metastatic disease. However, the clinical trials leading to these standards often require majority if not complete urothelial histology for eligibility. As many as one quarter of patients diagnosed with bladder cancer will have either divergent differentiation of their urothelial carcinoma or an alternate epithelial tumor such as squamous cell carcinoma, adenocarcinoma, or small cell carcinoma; even more rare are non-epithelial tumors such as sarcoma. The rarity of these diseases and their general exclusion from treatment within prospective clinical trials has created a challenging situation where treatment plans are often derived from case series or extrapolated from other disease types and outcomes are poor compared to pure urothelial carcinoma. In this review, we summarize the existing data on the diagnosis and treatment of epithelial, non-urothelial bladder cancers including adenocarcinoma, squamous cell carcinoma, and small cell carcinoma in their localized and advances stages. We will also review the current clinical trial landscape investigating novel approaches to these diseases.

[Occupation-related cancer in urology-Current knowledge including environmental medical aspects]

Occupation-related cancers are of considerable importance, which is not yet adequately recognized in the field of urology. The three numerically most significant entities are tumors of the urinary tract caused by carcinogenic aromatic amines or polycyclic aromatic hydrocarbons, renal cell cancer after high exposure to the solvent trichloroethylene, and mesotheliomas of the tunica vaginalis of the testis after exposure to asbestos; however, these can only be recognized as occupation-related if an occupational history regarding the hazard relevant to the organ bearing the tumor is documented from the beginning of employment, e.g. by a questionnaire. This is because the relevant exposures generally date back several decades. With the exception of high exposure to trichloroethylene, the substances mentioned can also environmentally trigger the same tumors. In the context of environmental risk factors, it is of considerable importance that smoking is now considered to be a trigger for some 50% of all bladder cancers in men and women; however, smoking cessation results in a reduction in smoking-related cancer risk of over 30% after only 3-4 years. Work and commuting accidents, which are considered occupational risks, can lead to urological sequelae. For example, increased tumors of the bladder can occur after spinal cord injury lasting longer than 10 years.

An Approach to Nonurothelial Malignancies of the Urinary Bladder in Urine Cytology

Urine cytology is an economical and convenient method of triaging patients who present with urinary symptoms as well as surveying those who have previously been diagnosed with urothelial carcinoma for recurrent or persistent disease. While the vast majority of malignancies diagnosed in urine cytology are urothelial carcinomas, it is important to recognize nonurothelial elements to inform patient prognosis and raise the possibility of involvement by a urothelial carcinoma variant, nonurothelial malignancy of the bladder, or a nonbladder primary, which may alter patient management pathways. As such, becoming familiar with morphologic features of nonurothelial malignancies in urine cytology as well as their related clinical risk factors, radiologic and cystoscopic features, differential diagnostic considerations, and the utility and pitfalls of ancillary tests can facilitate optimal patient care.

Programmed Cell Death-Ligand-1 expression in Bladder Schistosomal Squamous Cell Carcinoma – There’s room for Immune Checkpoint Blockage?

Schistosoma haematobium, the causative agent of urogenital schistosomiasis, is a carcinogen type 1 since 1994. It is strongly associated with bladder squamous-cell carcinoma in endemic regions, where it accounts for 53-69% of bladder-carcinoma cases. This histological subtype is associated with chronic inflammation being more aggressive and resistant to conventional chemo and radiotherapy. Immune-Checkpoint-Blockage (ICB) therapies targeting the Programmed-Cell-Death-Protein-1(PD-1)/Programmed-Cell-Death-Ligand-1(PD-L1) axis showed considerable success in treating advanced bladder urothelial carcinoma. PD-L1 is induced by inflammatory stimuli and expressed in immune and tumor cells. The binding of PD-L1 with PD-1 modulates immune response leading to T-cell exhaustion. PD-L1 presents in several isoforms and its expression is dynamic and can serve as a companion marker for patients’ eligibility, allowing the identification of positive tumors that are more likely to respond to ICB therapy. The high PD-L1 expression in bladder-urothelial-carcinoma and squamous-cell carcinoma may affect further ICB-therapy application and outcomes. In general, divergent histologies are ineligible for therapy. These treatments are expensive and prone to auto-immune side effects and resistance. Thus, biomarkers capable of predicting therapy response are needed. Also, the PD-L1 expression assessment still needs refinement. Studies focused on squamous cell differentiation associated with S. haematobium remain scarce. Furthermore, in low and middle-income-regions, where schistosomiasis is endemic, SCC biomarkers are needed. This mini-review provides an overview of the current literature regarding PD-L1 expression in bladder-squamous-cell-carcinoma and schistosomiasis. It aims to pinpoint future directions, controversies, challenges, and the importance of PD-L1 as a biomarker for diagnosis, disease aggressiveness, and ICB-therapy prognosis in bladder-schistosomal-squamous-cell carcinoma.

Molecular profile of pure squamous cell carcinoma of the bladder identifies major roles for OSMR and YAP signalling

Pure squamous cell carcinoma (SCC) is the most common pure variant form of bladder cancer, found in 2–5% of cases. It often presents late and is unresponsive to cisplatin‐based chemotherapy. The molecular features of these tumours have not been elucidated in detail. We carried out whole‐exome sequencing (WES), copy number, and transcriptome analysis of bladder SCC. Muscle‐invasive bladder cancer (MIBC) samples with no evidence of squamous differentiation (non‐SD) were used for comparison. To assess commonality of features with urothelial carcinoma with SD, we examined data from SD samples in The Cancer Genome Atlas (TCGA) study of MIBC. TP53 was the most commonly mutated gene in SCC (64%) followed by FAT1 (45%). Copy number analysis revealed complex changes in SCC, many differing from those in samples with SD. Gain of 5p and 7p was the most common feature, and focal regions on 5p included OSMR and RICTOR. In addition to 9p deletions, we found some samples with focal gain of 9p24 containing CD274 (PD‐L1). Loss of 4q35 containing FAT1 was found in many samples such that all but one sample analysed by WES had FAT1 mutation or deletion. Expression features included upregulation of oncostatin M receptor (OSMR), metalloproteinases, metallothioneins, keratinisation genes, extracellular matrix components, inflammatory response genes, stem cell markers, and immune response modulators. Exploration of differentially expressed transcription factors identified BNC1 and TFAP2A, a gene repressed by PPARG, as the most upregulated factors. Known urothelial differentiation factors were downregulated along with 72 Kruppel‐associated (KRAB) domain‐containing zinc finger family protein (KZFP) genes. Novel therapies are urgently needed for these tumours. In addition to upregulated expression of EGFR, which has been suggested as a therapeutic target in basal/squamous bladder cancer, we identified expression signatures that indicate upregulated OSMR and YAP/TAZ signalling. Preclinical evaluation of the effects of inhibition of these pathways alone or in combination is merited.

Expression and Prognostic Implication of PD-L1 in Patients with Urothelial Carcinoma with Variant Histology (Squamous Differentiation or Micropapillary) Undergoing Radical Cystectomy

The expression and prognostic role of programmed death ligand-1 (PD-L1) on tumor-infiltrating immune cells (TICs) has not been determined in urothelial carcinoma (UC) with variant histology. We retrospectively reviewed 90 patients (44 with micropapillary variant of UC (MPUC) and 46 with UC with squamous differentiation (UCSD)) who underwent radical cystectomy between January 2013 and December 2019. The expression of PD-L1 in TICs was measured using the VENTANA (SP-142) immunohistochemistry assay and dichotomized using a 5% cutoff value (positive ≥ 5%). Kaplan–Meier survival analysis was used to estimate recurrence-free survival (RFS), and multivariable Cox proportional hazard models were used to identify factors predicting tumor recurrence. Overall, positive PD-L1 expression in TICs was confirmed in 50 of 90 (55.6%) patients (40.1% (18/44) of MPUC and 69.9% (32/46) of UCSD). RFS was significantly shorter in patients with positive PD-L1 expression in TICs than in those with negative PD-L1 expression both in MPUC (p = 0.005) and UCSD (p = 0.046). Positive PD-L1 expression in TICs was significantly associated with an increased risk of tumor recurrence in both MPUC (HR = 1.85; 95% CI: 1.323–2.672; p = 0.017) and UCSD (HR = 1.58; 95% CI: 1.162–2.780; p = 0.032). In conclusion, positive PD-L1 expression in TICs was significantly associated with poorer RFS in both MPUC and UCSD patients. Our results support the use of adjuvant immunotherapy in these patients if they test positive for PD-L1 in their TICs.

Special surgical aspects of radical cystectomy in spinal cord injury patients with bladder cancer

PURPOSE

Radical cystectomy in people with spinal cord injury (SCI) provides numerous additional difficulties, compared to able-bodied people. Therefore, it is important to obtain information from an experienced team about optimally managing these patients.

METHODS

Surgical procedures, based on the experience of 12 radical cystectomies in SCI patients with bladder cancer between January 1st, 2001, and December 31st, 2020, were recorded and the operative and perioperative clinical data were evaluated. Surgery was performed in a high-volume center by the surgeon most experienced in radical cystectomies, assisted by the neuro-urologist, involved in the care of the patient from the spinal cord center. Furthermore, a checklist based on the experience of the surgeon and the assisting neuro-urologist was developed.

RESULTS

SCI patients mostly suffered from an advanced disease and were always operated by the same team. The hospital stays ranged from 23 to 134 days (median 42 days). Four of the patients suffered from a postoperative paralytic ileus. Otherwise, both the operation time and the intraoperative blood loss as well as intraoperative and postoperative complications were basically comparable with those in able-bodied patients. The special features of radical cystectomy in SCI bladder cancer patients are described. Furthermore, a checklist addressing preoperative red flags, intra-operative challenges and post-operative challenges is presented.

CONCLUSION

Radical cystectomy in SCI patients should be performed in a high-volume department by the most experienced surgical team. The inclusion of the urologist caring for the patient from the spinal cord injury center is highly recommended.