Receptor Tyrosine Kinase Pathway and Infiltrating Urothelial Carcinoma

Receptor tyrosine kinase pathway is frequently searched for cancer causing mutations in tumors. Emerging targeted therapies are gleam of hope for them. Infiltrating urothelial carcinoma can have many morphological aspects according to their differentiation/variants. To evaluate KRAS, BRAF, and PIK3CA mutations and HER2, EGFR, and p16 expression, we divided urothelial carcinomas into two groups: differentiated/variants (n = 12) and conventional (n = 12). We compared results with clinical, demographic, histopathologic features and survival rates. No statistically significant results could be obtained in the comparison of histopathologic properties/survival rates with mutation analysis and EGFR, HER2, and p16 status. Differentiated/variants urothelial carcinoma showed higher EGFR expression (P < 0.001). Glandular differentiation was the most frequent type, followed by squamous and sarcomatoid differentiation. We observed the most common mutation at KRAS with a propensity for urothelial carcinoma with glandular differentiation. More than one mutation/high protein expression was seen in some tumors. Targeted therapies for KRAS mutation can be effective at urothelial carcinoma with glandular differentiation. Heterologous expression of relevant proteins and genes can be a cause for targeted treatment obstacle. The determination of the molecular characters of tumors is a guide in creating targeted treatment algorithms and in choosing the patient.

Accurate Tumor Subtype Detection with Raman Spectroscopy via Variational Autoencoder and Machine Learning

Accurate diagnosis of cancer subtypes is a great guide for the development of surgical plans and prognosis in the clinic. Raman spectroscopy, combined with the machine learning algorithm, has been demonstrated to be a powerful tool for tumor identification. However, the analysis and classification of Raman spectra for biological samples with complex compositions are still challenges. In addition, the signal-to-noise ratio of the spectra also influences the accuracy of the classification. Herein, we applied the variational autoencoder (VAE) to Raman spectra for downscaling and noise reduction simultaneously. We validated the performance of the VAE algorithm at the cellular and tissue levels. VAE successfully downscaled high-dimensional Raman spectral data to two-dimensional (2D) data for three subtypes of non-small cell lung cancer cells and two subtypes of kidney cancer tissues. Gaussian naïve bayes was applied to subtype discrimination with the 2D data after VAE encoding at both the cellular and tissue levels, significantly outperforming the discrimination results using original spectra. Therefore, the analysis of Raman spectroscopy based on VAE and machine learning has great potential for rapid diagnosis of tumor subtypes.

Urethral Masses

Urethral and periurethral masses in women include both benign and malignant entities that can be difficult to clinically differentiate. Primary urethral carcinoma is rare and the optimal treatment modality may vary depending on the stage at presentation. Because cancer-free survival is poor, clinicians shouldhave a high index of suspicion when evaluating a urethral mass. Some benign-appearing urethral masses may be safely observed. Surgical resection is an effective option that should be used based on patient preference and symptoms, and for suspicious lesions.

European Association of Urology Guidelines on Primary Urethral Carcinoma-2020 Update

CONTEXT

Primary urethral carcinoma (PUC) is a rare cancer accounting for <1% of all genitourinary malignancies.

OBJECTIVE

To provide updated practical recommendations for the diagnosis and management of PUC.

EVIDENCE ACQUISITION

A systematic search interrogating Ovid (Medline), EMBASE, and the Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews was performed.

EVIDENCE SYNTHESIS

Urothelial carcinoma of the urethra is the predominant histological type of PUC (54-65%), followed by squamous cell carcinoma (16-22%) and adenocarcinoma (10-16%). Diagnosis of PUC depends on urethrocystoscopy with biopsy and urinary cytology. Pathological staging and grading are based on the tumour, node, metastasis (TNM) classification and the 2016 World Health Organization grading systems. Local tumour extent and regional lymph nodes are assessed by magnetic resonance imaging, and the presence of distant metastases is assessed by computed tomography of the thorax/abdomen and pelvis. For all patients with localised distal tumours (≤T2N0M0), partial urethrectomy or urethra-sparing surgery is a valid treatment option, provided that negative intraoperative surgical margins can be achieved. Prostatic Ta-Tis-T1 PUC can be treated with repeat transurethral resection of the prostate and bacillus Calmette-Guérin. In prostatic or proximal ≥ T2N0 disease, neoadjuvant cisplatin-based chemotherapy should be considered prior to radical surgery. All patients with locally advanced disease (≥T3N0-2M0) should be discussed within a multidisciplinary team. In men with locally advanced squamous cell carcinoma, curative radiotherapy combined with radiosensitising chemotherapy can be offered for definitive treatment and genital preservation. In patients with local urethral recurrence, salvage surgery or radiotherapy can be offered. For patients with distant metastatic disease, systemic therapy based on tumour characteristics can be evaluated.

CONCLUSIONS

These updated European Association of Urology guidelines provide up-to-date guidance for the contemporary diagnosis and management of patients with suspected PUC.

PATIENT SUMMARY

Primary urethral carcinoma (PUC) is a very rare, but aggressive disease. These updated European Association of Urology guidelines provide evidence-based guidance for clinicians treating patients with PUC.

pT1 high-grade bladder cancer: histologic criteria, pitfalls in the assessment of invasion, and substaging

Most patients with bladder carcinoma are diagnosed with non-muscle-invasive disease, stage Ta, and pT1. Stage remains as the single most important prognostic indicator in urothelial carcinoma. Among the pT1 bladder cancer patients, recurrence and progression of disease occur in 50% and 10%, respectively. The identification of high-risk patients within the pT1 subgroup remains an important clinical goal and an active field of research. Substaging of pT1 disease has been claimed as important histologic discriminator by the 2016 World Health Organization (WHO) classification of the genitourinary tract tumors and by the 8th edition of the American Joint Committee on Cancer (AJCC) staging manual supporting its implementation in clinical practice. Interobserver variation in pT1 diagnosis and the associated pitfalls in pT1 assessment are the critical pathological issues. The aim of this review paper is to provide the practicing pathologist with the state of the art of morphological and immunohistochemical features useful for the diagnosis of early invasive bladder carcinomas, including practical clues on how to avoid relevant interpretative pitfalls, and to summarize the current status of pT1 substaging.

Low Frequency of Intratumor Heterogeneity in Bladder Cancer Tissue Microarrays

Background

Intratumoral heterogeneity (ITH) is associated with clinical challenges such as possible differences in response to treatment and difficulties in classifying the tumor. Previously, ITH has been described in bladder cancer using detailed genetic analyses. However, in this disease, it is not known to what extent ITH actually occurs, or if it involves molecular subtyping, when assessment is achieved by immunohistochemistry (IHC) on the protein level using tissue microarrays (TMAs), the method most widely applied when analyzing large sample numbers.

Objective

We aimed to investigate ITH by IHC in bladder cancer TMAs.

Methods

Staining for eleven immunohistochemical markers (CK5, Cyclin D1, E-Cadherin, EGFR, FGFR, GATA3, HER2, p16, p63, P-Cadherin and RB1) was performed, and differences in staining patterns were assessed both within 1981 individual tissue-cores and by comparing two cores from the same tumor in 948 cases according to our pre-specified criteria. Presence of ITH was associated with clinicopathological data such as stage, grade, molecular subtype and survival.

Results

Intracore ITH in one or several markers was associated with grade 3, stage T1 and the genomically unstable molecular subtype. ITH in three or more markers was found in 5% between cores (intercore heterogeneity) and in 2% within cores (intracore heterogeneity). No association with survival was found for any of the ITH groups.

Conclusions

We observed ITH in a small proportion of the tumors, suggesting that ITH has only a limited impact on TMA bladder cancer studies.

Rare urologic tumors

PURPOSE OF REVIEW

Management of genitourinary malignancy is likely to encompass a large portion of most of the urologist's practice. The challenge for the modern urologist is not only in understanding the management of commonly seen genitourinary malignancies, but also in recognizing unusual variants and their differences in management. This is evermore important as new technologies have refined the ability to identify rare entities. This review presents a brief overview of the various genitourinary malignancy subtypes seen within urology.

RECENT FINDINGS

All major organ subtypes are highlighted along with an overview of the current understanding of their associated malignancies. An update on the current state management paradigms as well as future directions is also outlined.

SUMMARY

After reading this review, the urologist should have a deeper understanding of the breadth of disorders in genitourinary oncology and a clearer approach to the management of these problems. Additionally, ongoing avenues for research are highlighted.

The prognostic effect of salvage surgery and radiotherapy in patients with recurrent primary urethral carcinoma

BACKGROUND

To evaluate the impact of salvage therapy (ST) on overall survival (OS) in recurrent primary urethral cancer (PUC).

PATIENTS

A series of 139 patients (96 men, 43 women; median age = 66, interquartile range: 57-77) were diagnosed with PUC at 10 referral centers between 1993 and 2012. The modality of ST of recurrence (salvage surgery vs. radiotherapy) was recorded. Kaplan-Meier analysis with log-rank was used to estimate the impact of ST on OS (median follow-up = 21, interquartile range: 5-48).

RESULTS

The 3-year OS for patients free of any recurrence (I), with solitary or concomitant urethral recurrence (II), and nonurethral recurrence (III) was 86.5%, 74.5%, and 48.2%, respectively (P = 0.002 for I vs. III and II vs. III; P = 0.55 for I vs. II). In the 80 patients with recurrences, the modality of primary treatment of recurrence was salvage surgery in 30 (37.5%), salvage radiotherapy (RT) in 8 (10.0%), and salvage surgery plus RT in 5 (6.3%) whereas 37 patients did not receive ST for recurrence (46.3%). In patients with recurrences, those who underwent salvage surgery or RT-based ST had similar 3-year OS (84.9%, 71.6%) compared to patients without recurrence (86.7%, P = 0.65), and exhibited superior 3-year OS compared to patients who did not undergo ST (38.0%, P<0.001 compared to surgery, P = 0.045 to RT-based ST, P = 0.29 for surgery vs. RT-based ST).

CONCLUSIONS

In this study, patients who underwent ST for recurrent PUC demonstrated improved OS compared to those who did not receive ST and exhibited similar survival to those who never developed recurrence after primary treatment.

S100P as a Marker for Urothelial Histogenesis: A Critical Review and Comparison With Novel and Traditional Urothelial Immunohistochemical Markers

S100P, or placental S100, is a member of a large family of S100 proteins and considered to be a promising immunohistochemical marker to support urothelial differentiation. This review synthesizes published data regarding the expression of S100P in urothelial carcinoma across histological grade and variant patterns, and in other malignancies, in an effort to summarize the state of understanding of this marker and evaluate its potential. We provide also a broad comparison of S100P with other contemporary and traditional urothelial markers and outline the potential utility of S100P in various diagnostically challenging scenarios. Taken in context, we recommend that to provide immunohistochemical support for consideration of urothelial differentiation, S100P may be included in a panel of markers (due to its high sensitivity), with better established (GATA3) and more specific (uroplakin 2) markers, for comparison with corresponding markers of other primary sites under consideration, depending on the clinical context. We emphasize that the overall most appropriate panel for any given case depends on the differential diagnosis engendered by the morphology encountered, and the constellation of clinical findings. As always with immunohistochemical panels, expected positive and negative markers for each diagnostic consideration should be included. Finally, since as of date there are no optimally sensitive or specific markers of urothelial differentiation, all final diagnoses relying on immunohistochemical support should be made in the appropriate clinical and histological context.

Challenges in Pathologic Staging of Bladder Cancer: Proposals for Fresh Approaches of Assessing Pathologic Stage in Light of Recent Studies and Observations Pertaining to Bladder Histoanatomic Variances

The paradigm of pathologic stage (pT) categorization in bladder cancer remains the depth of invasion into the different histologic layers of the bladder wall. However, the approaches to assigning pT stage category toward an enhanced outcome stratification have been marked by challenges and innovations, due in part to our growing appreciation of the surprisingly perplexing bladder histoanatomy. Upstaging of pT1 tumors after radical cystectomy is substantial and underscores the potential value of pT1 substaging in transurethral resection (TUR) specimens. The 2017 American Joint Committee on Cancer tumor-node-metastasis system recommends pT1 substaging but recognizes the need to optimize the approach. Over the years, the cut-off for microinvasion has been significantly lowered to 0.5 mm and is now a promising scheme for pT1 (micrometric) substaging. Unlike the micrometric approach, histoanatomic substaging using muscularis mucosae (MM) and vascular plexus as landmarks is less feasible in TUR specimens and inconsistent in stratifying the outcome of pT1 tumors. The lamina propria possesses inherent variations in depth, MM, and vascular plexus dispositions that should be factored in future pT1 substaging proposals. Histoanatomic variations among the bladder regions also occur, and studies suggest that trigone and bladder neck cancers may have more adverse outcomes. The muscularis propria (MP), besides being the essential histologic landmark for assigning pT2 stage category, is also considered a surrogate for the adequacy of TUR, furthering the importance of identifying its presence in TUR specimens. MP, however, may be mimicked by hyperplastic or isolated MP-like MM muscle bundles in the lamina propria with overstaging implications, and caution should be exercised in distinguishing these 2 muscle types morphologically and immunohistochemically. Presence of additional superficial MP unique from the detrusor muscle proper may also complicate staging at the trigone and ureter insertion sites. With regard to the depth of MP invasion, large and multicenter studies have reaffirmed the prognostic significance of pT2a/b subcategories. It is revealed that there are at least 3 ways used to demarcate the irregular MP to perivesical soft tissue junction, and use of a common criterion indicates improvement in pT2b/pT3a staging reproducibility. Although studies have shown significantly poorer outcome in pT3b compared with pT3a tumors, this designation has a substantial reliance on the prosector's gross assessment of perivesical soft tissue invasion which if performed incorrectly may lead to staging inaccuracy of pT3 tumors. The 8th edition of the American Joint Committee on Cancer has updated the staging schema for bladder cancers with concomitant prostatic stromal invasion and cancers within bladder diverticula. Because of 2 possible pT designations, prostatic stromal invasion in TUR specimens should not be automatically staged as either pT4a or pT2 (urethral). Recent data support that bladder cancer invading into the seminal vesicle has comparable outcome to pT4b tumors. Interestingly, several studies in pT4a tumors, which are staged based on sex-specific organs, have shown poorer outcome in females than males after radical cystectomy, and while there are possibly several reasons, they may also include anatomic factors. Despite the progress has been made, work remains to be done to inform future bladder cancer pT category definitions and their reproducibility in application and prognostication.