Editorial Comment from Dr Szarvas and Dr Reis to Clinicopathological features of malignant urachal tumor: A hospital-based cancer registry data in Japan

Glandular Lesions of the Urinary Bladder: Diagnostic and Molecular Updates

Glandular lesions in the urinary tract or their associated pathologies can pose a diagnostic challenge. There is a variety of benign alterations and tumor types that need to be taken into account in differential diagnostic considerations. In recent times, efforts for better defining these alterations or lesions both on the histopathological and molecular levels have been undertaken. This article will provide an update on current diagnostic and molecular considerations of these lesions.

Clinical sequencing identifies potential actionable alterations in a high rate of urachal and primary bladder adenocarcinomas

OBJECTIVE

Administration of targeted therapies provides a promising treatment strategy for urachal adenocarcinoma (UrC) or primary bladder adenocarcinoma (PBAC); however, the selection of appropriate drugs remains difficult. Here, we aimed to establish a routine compatible methodological pipeline for the identification of the most important therapeutic targets and potentially effective drugs for UrC and PBAC.

METHODS

Next-generation sequencing, using a 161 cancer driver gene panel, was performed on 41 UrC and 13 PBAC samples. Clinically relevant alterations were filtered, and therapeutic interpretation was performed by in silico evaluation of drug-gene interactions.

RESULTS

After data processing, 45/54 samples passed the quality control. Sequencing analysis revealed 191 pathogenic mutations in 68 genes. The most frequent gain-of-function mutations in UrC were found in KRAS (33%), and MYC (15%), while in PBAC KRAS (25%), MYC (25%), FLT3 (17%) and TERT (17%) were recurrently affected. The most frequently affected pathways were the cell cycle regulation, and the DNA damage control pathway. Actionable mutations with at least one available approved drug were identified in 31/33 (94%) UrC and 8/12 (67%) PBAC patients.

CONCLUSIONS

In this study, we developed a data-processing pipeline for the detection and therapeutic interpretation of genetic alterations in two rare cancers. Our analyses revealed actionable mutations in a high rate of cases, suggesting that this approach is a potentially feasible strategy for both UrC and PBAC treatments.

A new technological approach in diagnostic pathology: mass spectrometry imaging-based metabolomics for biomarker detection in urachal cancer

Urachal adenocarcinomas (UrC) are rare but aggressive. Despite being of profound therapeutic relevance, UrC cannot be differentiated by histomorphology alone from other adenocarcinomas of differential diagnostic importance. As no reliable tissue-based diagnostic biomarkers are available, we aimed to detect such by integrating mass-spectrometry imaging-based metabolomics and digital pathology, thus allowing for a multimodal approach on the basis of spatial information. To achieve this, a cohort of UrC (n = 19) and colorectal adenocarcinomas (CRC, n = 27) as the differential diagnosis of highest therapeutic relevance was created, tissue micro-arrays (TMAs) were constructed, and pathological data was recorded. Hematoxylin and eosin (H&E) stained tissue sections were scanned and annotated, enabling an automized discrimination of tumor and non-tumor areas after training of an adequate algorithm. Spectral information within tumor regions, obtained via matrix-assisted laser desorption/ionization (MALDI)-Orbitrap-mass spectrometry imaging (MSI), were subsequently extracted in an automated workflow. On this basis, metabolic differences between UrC and CRC were revealed using machine learning algorithms. As a result, the study demonstrated the feasibility of MALDI-MSI for the evaluation of FFPE tissue in UrC and CRC with the potential to combine spatial metabolomics data with annotated histopathological data from digitalized H&E slides. The detected Area under the curve (AUC) of 0.94 in general and 0.77 for the analyte taurine alone (diagnostic accuracy for taurine: 74%) makes the technology a promising tool in this differential diagnostic dilemma situation. Although the data has to be considered as a proof-of-concept study, it presents a new adoption of this technology that has not been used in this scenario in which reliable diagnostic biomarkers (such as immunohistochemical markers) are currently not available.

Urachal Cancer in Germany and the USA: An RKI/SEER Population-Based Comparison Study

INTRODUCTION

Urachal cancer (UrC) is a rare but aggressive cancer. Due to its low incidence, structured epidemiological data have only rarely been reported. To date, no valid data on UrC are available for the German population.

METHODS

Data on incidence and relative 5-year survival of urachal lesions (ICD-10: C67.7) were collected from all population-based cancer registries in Germany, provided by the Robert Koch-Institut (RKI). Data were anonymized and included age, sex, and general histology (ICD-O-3). For comparison, a similar inquiry of the "Surveillance, Epidemiology, and End Results program" (SEER-18) database for the USA was conducted.

RESULTS

From 2011 to 2015, a total of 154 and 152 cases of UrC were reported for Germany (RKI) and the USA (SEER-18 area), respectively. Age-standardized incidence was 0.32/1,000,000 age-standardized cases/year in both cohorts, and elderly persons were more often affected. The major histological type was adenocarcinoma (64.9 and 81.6%). Relative 5-year survival was 54.8% (CI: 45.0-64.6) in Germany (RKI) and 64.4% (54.1-72.1) in the USA (SEER-18 cohort). Discusssion/Conclusion: The collected data demonstrate low incidence rates and similar epidemiological and clinicopathological characteristics of UrC for both registries. This is the first report of structured epidemiological data for UrC for the German population.