Biomarkers in Urachal Cancer and Adenocarcinomas in the Bladder: A Comprehensive Review Supplemented by Own Data

Estimation of the incidence of urachal cancer: A systematic review and meta-analysis of registry-based studies

BACKGROUND

Urachal cancer (UrC) is a rare disease with limited availability of representative incidence and clinical data. Although, the prevalence is accounting for less than 1% of bladder tumors, the 5-year survival rate is around only 50% for patients with resectable tumors, and even worse for patients with metastatic disease. Due to the lack of comprehensive prospective studies, our current knowledge of UrC is still limited.

OBJECTIVE

The present study aimed to summarize the available registry-based studies with unselected UrC patients to evaluate its incidence and clinicopathological characteristics.

MATERIAL AND METHODS

We conducted a systematic literature search of registry-based UrC publications on the 15th of May 2023 in 5 databases, which identified 4,748 publications. After duplicate removal and selection by 2 independent investigators, 6 publications proved to be appropriate for the final meta-analysis. Estimated incidence and clinicopathological parameters were extracted.

RESULTS

Estimated incidence ranged between 0.022 and 0.060/ 100.000 person-years, with the highest occurrence in Japan and the lowest in Canada, while the random effect model calculated an overall incidence rate of 0.04 (95%CI: 0.03-0.05) 100.000 person-years. The median age at first diagnosis was 60 years (range: 58-64). The female to male ratio was 2:3. Lymph node or distant metastases were present in 9% and 14% of patients. The predominant tumour type was adenocarcinoma (86%) followed by urothelial carcinoma (12%) and squamous cell carcinoma (2%). The 5-year survival rate was 51.0% with 95%CI: 45.2-57.4.

CONCLUSIONS

Our study provides an up-to-date comparison of estimated incidence rates between 6 countries of 3 continents based on rigorously selected registry-based studies. The results suggest low incidence rates for UrC with considerable geographic differences. The present meta-analysis provides unbiased registry-based data on the incidence, clinicopathological parameters and survival of UrC.

[Rare tumors and tumor types of the urinary system in the 5th edition of the WHO classification 2022]

The 5th edition of the World Health Organization (WHO) classification of tumors of the urinary tract and male genital organs introduced both general and specific changes in structure, classification, and nomenclature. This also applies to rarer tumors and tumor subtypes of the urinary system. Knowledge of these changes is relevant for routine histopathological work. This article provides an overview of the main new features of the rarer tumors and tumor subtypes of the urinary system in the new edition of the WHO classification.

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.

The Application and Pitfalls of Immunohistochemical Markers in Challenging Diagnosis of Genitourinary Pathology

CONTEXT.—

The morphologic features of different entities in genitourinary pathology overlap, presenting a diagnostic challenge, especially when diagnostic materials are limited. Immunohistochemical markers are valuable when morphologic features alone are insufficient for definitive diagnosis. The World Health Organization classification of urinary and male genital tumors has been updated for 2022. An updated review of immunohistochemical markers for newly classified genitourinary neoplasms and their differential diagnosis is needed.

OBJECTIVE.—

To review immunohistochemical markers used in the diagnosis of genitourinary lesions in the kidney, bladder, prostate, and testis. We particularly emphasized difficult differential diagnosis and pitfalls in immunohistochemistry application and interpretation. New markers and new entities in the 2022 World Health Organization classifications of genitourinary tumors are reviewed. Recommended staining panels for commonly encountered difficult differential diagnoses and potential pitfalls are discussed.

DATA SOURCES.—

Review of current literature and our own experience.

CONCLUSIONS.—

Immunohistochemistry is a valuable tool in the diagnosis of problematic lesions of the genitourinary tract. However, the immunostains must be carefully interpreted in the context of morphologic findings with a thorough knowledge of pitfalls and limitations.

Urachus adenocarcinoma mistaken for umbilical incision implant cancer after laparoscopic cholecystectomy: a case report

Umbilical incision implant cancer after LC is rare. Elective cholecystectomy was planned for a 49 years-old female patient with symptomatic gallstones. The patient underwent transumbilical single-port LC after admission to our hospital. Gallbladder specimens were obtained directly through the umbilical puncture hole, and histopathology suggested chronic cholecystitis. Three months after surgery, the patient experienced painful induration in the umbilicus. We initially considered incision scar hyperplasia complicated with pain, and used drugs to treat it conservatively without taking special treatment measures. Six months after LC, the umbilical induration pain affected her quality of life, and the patient requested surgical resection. Preoperative ultrasonography and abdominal computerized tomography (CT) revealed nodular changes around the umbilicus and no abdominal mass. Local resection of the periumbilical mass was performed, and the pathological confirmation was invasive adenocarcinoma. Subsequently, the patient underwent repeat periumbilical mass enlargement resection. Postoperative pathology showed no cancer at the enlarged resection margin, yet the umbilical center pathology showed invasive adenocarcinoma. The excised pathology was sent to the Sun Yat-sen University Cancer Center for consultation because of the rare nature of the findings associated with the case. After consultation, a diagnosis of umbilical urachus adenocarcinoma was confirmed based on pathological morphology, immunohistochemistry, and the specific anatomical location of the tumor. This case report shown that when there is a persistent mass induration in the navel after LC surgery, the possibility of incision tumor should be considered, rather than simply excluding the possibility of a cancer based on a non-cancer medical history.

Urachal Adenocarcinoma: a Case Report and Review of the Literature

Urachal adenocarcinoma is one of the rare and aggressive neoplasms that often presents at an advanced stage and has a poor prognosis. Urachal adenocarcinoma makes up 0.17 to 0.34% of all bladder carcinomas. Patients commonly present with hematuria. Wide local excision of urachal mass with umbilicus and surrounding soft tissue en bloc combined with partial or radical cystectomy and bilateral pelvic lymphadenectomy is considered to be the primary surgical management. However, many publications in literature report that en bloc removal of tumor with umbilicus, entire urachal ligament, and bladder dome alone has long-term survival and disease-free period. Here, we present a case of a 50-year-old post-menopausal female patient with a fungating mass in the umbilical region of size approximately 10 cm in maximum diameter with mucopurulent discharge from the mass. The patient had no history of any hematuria, mucinuria, burning micturition, or any particles in urine. A laparotomy was performed, and tumor mass along with the cuff of the bladder dome was removed as en bloc along with umbilectomy. This case report highlights a rare case of urachal adenocarcinoma with a fungating mass of large size in a female patient which is otherwise more commonly seen in males. A review of published literature is also presented.

Clinical value of preoperative serum tumor markers CEA, CA19-9, CA125, and CA15-3 in surgically treated urachal cancer

INTRODUCTION

Urachal adenocarcinoma (UrAC) is a very rare malignancy with a poor prognosis. The role of preoperative serum tumor markers (STMs) in UrAC is unknown. The aim of this study was to assess the clinical value of elevated STMs including carcinoembryonic antigen (CEA), cancer antigen 19-9 (CA19-9), cancer antigen 125 (CA125), and cancer antigen 15-3 (CA15-3) in surgically treated UrAC, and to evaluate their prognostic significance.

METHODS

This was a retrospective study of consecutive patients with histopathologically confirmed UrAC who underwent surgical treatment at a single tertiary hospital. Blood levels of CEA, CA19-9, CA125, and CA15-3 were determined before surgery. The proportion of patients with elevated STMs was calculated, as well as the association between elevated STMs and clinicopathological characteristics, recurrence-free survival and disease-specific survival.

RESULTS

Of the 50 patients included; CEA, CA 19-9, CA125, and CA15-3 were elevated in 40%, 25%, 26%, and 6% respectively. Elevated CEA was associated with higher pT-stage (odds ratio [OR] 3.3 [95% confidence interval 1.0-11.1], P = 0.003), higher Sheldon stage (OR 6.9 [95% CI 0.8-60.4], P = 0.01), male sex (OR 4.7 [95% CI 1.2-18.3], P = 0.01), and the presence of peritoneal metastases at the time of diagnosis (OR 3.5 [95% CI 0.9-14.2], P = 0.04). Elevated CA19-9 was associated with signet-cell component (OR 1.7 [95% CI 0.9-3.3], P = 0.03) and elevated CA125 was associated with peritoneal metastases at the time of diagnosis (OR 6.0 [95% CI 1.2-30.6], P = 0.04). Elevated STMs before surgery were not associated with recurrence-free survival and/or disease-specific survival.

CONCLUSION

A subset of patients with surgically treated UrAC has elevated STMs preoperatively. CEA was most frequently (40%) elevated and correlated with unfavorable tumor characteristics. However, STM levels did not correlate with prognostic outcomes.

A Huge Asymptomatic Urachal Mucinous Cystic Carcinoma: A Case Report With Differential Diagnosis and Surgical Considerations

Cystic mucinous neoplasms of urachal origin cover a wide spectrum of benign and malignant lesions arising from the remnants of the urachus. They display various degrees of tumor cell atypia and local invasion, with no reported cases of metastasis or recurrence after complete surgical resection. We present a 47-year-old man who referred to our Surgical Department due to an abdominal cystic mass incidentally found upon abdominal ultrasound. He underwent en block resection of the cystic mass along with partial bladder dome cystectomy. The histopathology of the resected specimen revealed a cystic mucinous epithelial tumor of low malignant potential with areas of intraepithelial carcinoma. The patient showed no evidence of disease recurrence or distant metastasis 6 months after resection and is scheduled for follow-up with serial MRI or CT scans and blood tumor markers over the next 5 years.

Preoperative accuracy of diagnostic evaluation of urachal carcinoma

BACKGROUND

We analyzed the clinical data of patients with urachal carcinoma (UrC) in order to strengthen urologists' understanding of UrC and improve preoperative diagnosis.

METHODS

The clinical data of 37 patients with UrC admitted to our hospital from October 2005 to April 2022 were retrospectively analyzed, and 40 patients with urothelial carcinoma (UCa) of bladder were enrolled as the control group. We compared and analyzed the imaging, cystoscopy and immunohistochemistry, serum tumor markers, fluorescence in situ hybridization (FISH) of UrC and bladder UCa for early diagnosis and evaluation of diagnostic accuracy.

RESULTS

A total of 37 patients with UrC were enrolled in this study, including 30 males and seven females, with a median age of 52.00 (44.50-63.50) years. Imaging and cystoscopy suggest that UrC grows primarily outside the bladder cavity and is found in the middle line of the dome or anterior wall of the bladder. There was a significant difference in tumor location between the UrC group and the UCa group (10.13 mm vs. -7.06 mm, p < 0.001). Immunohistochemistry revealed that CK20 and CDX-2 were both diffusely and strongly positive. β-catenin was strongly positive in cytoplasm and membrane, but negative in nuclear staining. Carcinoembryonic antigen (CEA) and carbohydrate antigen 72-4 (CA724) expression levels were significantly higher in the UrC group than in the UCa group (p < 0.05). In the diagnosis of UrC, the area under the curve (AUC) of CEA combined with CA724 was the greatest. FISH's sensitivity in diagnosing UrC (5/7, 71.43%) was not significantly different from that of UCa (71.43% vs. 77.50%, p = 0.659). Imaging examination has the highest sensitivity and specificity among the accuracy evaluation of different diagnostic methods.

CONCLUSIONS

Imaging and cystoscopy are the powerful diagnostic methods for UrC. Serum tumor markers may assist in diagnosis, prognosis, and monitoring. Positive urine FISH can easily misdiagnose UrC as UCa.

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.

Urachal carcinoma: a large retrospective multicentric study from the French Genito-Urinary Tumor Group

Introduction

Urachal cancer (UrC) is a rare, non-urothelial malignancy. Its natural history and management are poorly understood. Although localized to the bladder dome, the most common histological subtype of UrC is adenocarcinoma. UrC develops from an embryonic remnant, and is frequently diagnosed in advanced stage with poor prognosis. The treatment is not standardized, and based only on case reports and small series. This large retrospective multicentric study was conducted by the French Genito-Urinary Tumor Group to gain a better understanding of UrC.

Material and Methods

data has been collected retrospectively on 97 patients treated at 22 French Cancer Centers between 1996 and 2020.

Results

The median follow-up was 59 months (range 44-96). The median age at diagnosis was 53 years (range 20-86), 45% were females and 23% had tobacco exposure. For patients with localized disease (Mayo I-II, n=46) and with lymph-node invasion (Mayo III, n=13) median progression-free-survival (mPFS) was 31 months (95% CI: 20-67) and 7 months (95% CI: 6-not reached (NR)), and median overall survival (mOS) was 73 months (95% CI: 57-NR) and 22 months (95% CI: 21-NR) respectively. For 45 patients with Mayo I-III had secondary metastatic progression, and 20 patients were metastatic at diagnosis. Metastatic localization was peritoneal for 54% of patients. Most patients with localized tumor were treated with partial cystectomy, with mPFS of 20 months (95% CI: 14-49), and only 12 patients received adjuvant therapy. Metastatic patients (Mayo IV) had a mOS of 23 months (95% CI: 19-33) and 69% received a platin-fluorouracil combination treatment.

Conclusion

UrC is a rare tumor of the bladder where patients are younger with a higher number of females, and a lower tobacco exposure than in standard urothelial carcinoma. For localized tumor, partial cystectomy is recommended. The mOS and mPFS were low, notably for patients with lymph node invasion. For metastatic patients the prognosis is poor and standard therapy is not well-defined. Further clinical and biological knowledge are needed.

Treatment options and prognostic risk factors for urachal carcinoma: A multicetnter retrospective study

PURPOSE

Urachal carcinoma (UC) is a rare genitourinary cancer with an insidious onset, high risk of recurrence, and a poor prognosis. Surgical resection alone has difficulty in controlling the tumor. We aim to explore treatment options and prognostic risk factors for UC based on a multicenter cohort and long-term follow-up database.

MATERIALS AND METHODS

The clinical data, treatment and follow-up results of 163 patients with UC in 6 medical centers were analyzed retrospectively. Kaplan-Meier analysis and a Cox proportional hazards model were used to assess the treatment options and prognostic risk factors for UC.

RESULTS

Kaplan-Meier analysis showed no difference in the 5-year recurrence-free survival rate (P =0.282) or overall survival rate (P =0.673) between extended partial cystectomy (EPC) and radical cystectomy (RC) for patients at stage III and below. Whether bilateral pelvic lymph nodes were dissected was also not significantly correlated with the patient's recurrence (P =0.921) or prognosis (P =0.741). Postoperative adjuvant chemotherapy significantly reduced the recurrence rate of patients with stage Ⅲb or below (P =0.005). Combined treatment of postoperative recurrence patients prolonged the survival time of patients compared with single chemotherapy or conservative treatment (34.022±5.031 vs. 12.837±2.349 or 6.192±0.875 months, P <0.001). Kaplan-Meier and univariate Cox regression analyses showed that age >55 years, Sheldon stage, carbohydrate antigen 19-9 (CA19-9) >9.935 U/mL, carbohydrate antigen 72-4 (CA724) >6.02 U/mL, and postoperative adjuvant chemotherapy were closely related to the overall survival and recurrence-free survival of patients (P <0.05). Multivariate Cox proportional hazard regression confirmed that the Sheldon stage and CA724 >6.02 U/mL were independent recurrence risk factors.

CONCLUSIONS

EPC or RC provides similar oncologic results for UC, but bilateral pelvic lymph node dissection is not necessary in early-stage patients. Postoperative adjuvant chemotherapy can significantly reduce the recurrence rate, and combination therapy may provide better survival outcomes. CA724 can predict tumor recurrence or metastasis at an early stage.

Urachal Carcinoma, An Unusual Possibility of Hematuria; Case Report and Literature Review

Urachal cancer is very rare, accounting for only 0.5–2% of bladder-associated malignancies and 0.01% of all cancers in adults. It has an insidious appearance, an aggressive behavior and a poor prognosis. The most common symptoms are hematuria and the presence of a palpable hypogastric mass. The scarcity of cases and the low number of studies carried out explains the lack of an evidence-based management strategy, but it seems that surgical treatment (open, laparoscopy or robot-assisted) represents the gold standard, while neoadjuvant and adjuvant chemotherapy or radiotherapy has a limited impact on overall survival. Since mucinous cystadenocarcinoma of urachal origin is a very uncommon pathological condition the differential diagnosis may be difficult and pathological investigations have to elucidate this disorder. It is worth mentioning the psychological impact on the patient in addition to the medical aspects. A rare condition is associated with heightened risk for mental health and psychosocial difficulties and this must be taken into account in the subsequent follow-up of the patient. In order to increase awareness of this rare entity we report a case of a 40-year-old male with a urachal adenocarcinoma who was treated surgically, with a favorable outcome. We also perform a brief literature review about this type of tumor.

Web-Based Prediction Models for Overall Survival and Cancer-Specific Survival of Patients With Primary Urachal Carcinoma: A Study Based on SEER Database

Objective:

We aimed to establish nomograms to predict the overall survival (OS) and cancer-specific survival (CSS) of patients with primary urachal carcinoma (UrC).

Methods

Information on patients diagnosed with UrC from 1975 to 2018 was collected from the Surveillance, Epidemiology, and End Results (SEER) Program Research Data. The independent prognostic factors were determined using univariate and multivariate Cox regression. Backward variable elimination according to the Akaike information criterion (AIC) identified the most accurate and parsimonious model. Nomograms were built based on regression coefficients. The C-index, calibration plot, Brier score, integrated discrimination improvement (IDI), area under the receiver operating curve (AUC), and decision curve analysis (DCA) curve were used to evaluate the efficiency of models.

Results

In total, 236 patients obtained from SEER were divided randomly into training and validation cohorts in a 70:30 ratio (166 and 70 patients, respectively). In the training cohort, multivariate Cox regression analysis indicated that pTNM/Sheldon/Mayo staging systems (included respectively), age, and tumor grade were independent prognostic factors for OS. A similar result was also found in CSS. While other variables, such as radiotherapy and chemotherapy, did not identify significant correlations. In predicting OS and CSS at 3- and 5- years, the nomograms based on pTNM showed superior discriminative and calibration capabilities in comparison to multiple statistical tools. The C-index values for the training cohort were 0.770 for OS and 0.806 for CSS, and similar outcomes were shown in further internal validation (C-index 0.693 for OS and 0.719 for CSS). We also discovered that the link between age at diagnosis and survival follows a U-shaped curve, indicating that the risk of poor prognosis decreases first and then increases with age.

Conclusion

The efficacy of pTNM in predicting the prognosis of patients with UrC was greater than that of the Sheldon and Mayo staging system. Therefore, we recommend pTNM as the preferred system to stage UrC. The novel constructed nomograms based on pTNM, age, and tumor grade showed high accuracy and specificity and could be applied clinically to predict the prognosis of patients with UrC.

Clinical outcomes and patterns of population-based management of urachal carcinoma of the bladder: An analysis of the National Cancer Database

BACKGROUND

Given the low incidence of urachal carcinoma of the bladder (UCB), there is limited published data from contemporary population-based cohorts. This study aimed to describe demographic, clinicopathological features, and survival outcomes of patients diagnosed with UCB.

METHODS

The National Cancer Database (2004-2016) was queried for UCB patients. Descriptive analyses characterized demographics and clinicopathologic features. We assessed 5-year overall survival (OS) rates of the entire cohort and subgroups of localized/locally advanced and metastatic disease. We utilized Cox proportional hazards models to assess the association between covariates of interest and all-cause mortality and to examine the impact of surgical technique and chemotherapy.

RESULTS

We identified 841 patients with UCB. The most common histologic subtype was non-mucinous adenocarcinoma (39.6%). Approximately 50% had ≥cT2 disease, and 14.3% were metastatic at diagnosis. Altogether, partial cystectomy (60%) was most performed, and lymph node dissection was performed in 377 patients (44.8%), with specific temporal increase in utilization over the study period (p < 0.001). Overall, median OS was 59 months, and 5-year OS was 49%. In patients with localized/locally advanced disease, we found no association between partial and radical cystectomy (Hazards ratio [HR] 1.75; 95% CI 0.72-4.3) as well as receipt of perioperative chemotherapy (HR 1.97, 95% CI 0.79-4.90) and outcomes. Lastly, receipt of systemic therapy was not associated with survival benefit (HR 0.785, 95% CI 0.37-1.65) in metastatic disease cohort.

CONCLUSION

This large population-based cohort provides insight into the surgical management and systemic therapy, without clear evidence on the association of chemotherapy and survival in the perioperative and metastatic setting.

Current Management of Urachal Carcinoma: An Evidence-based Guide for Clinical Practice

Urachal carcinoma is a rare urological disease. The shortage of data about diagnosis and surgical treatment in literature makes it hard for clinicians to make a decision. Indeed, urachal carcinoma is an aggressive disease that requires prompt staging and treatment to ensure the best outcome for patients. We reviewed the last evidence about the management of urachal carcinoma to provide an easy-to-use guide for clinical practice.

Patient summary

Urachal carcinoma is a rare malignancy. The literature on this challenging disease remains limited. Herein, we provide a practical guide for its management from diagnosis to treatment, which in most cases requires surgical intervention or chemotherapy.

18F-FDG PET/CT in a Case of Urothelial Carcinoma in the Urachus Presenting as Colon Cancer

Urachal cancer arises from an embryologic remnant of the urogenital sinus and allantois and accounts for approximately 1% of bladder malignancies. The most encountered histologic subtype is adenocarcinoma. We present a 76-year-old man suspected to have an advanced sigmoid cancer infiltrating nearby organs. A supplemental 18F-FDG PET/CT showed high tracer uptake in a tumorous process coherent with the dome of the bladder wall involving the sigmoid colon. Cystoscopy revealed a normal bladder wall, except for a small edematous area in the anterior bladder. Biopsies from the sigmoid colon and transurethral resection from the bladder confirmed a urothelial carcinoma originating from the urachus.

Construction and Validation of Novel Prediction Tools Based on Large Population-Based Database to Predict the Prognosis of Urachal Cancer After Surgery

Background

Urachal cancer is a rare neoplasm in the urological system. To our knowledge, no published study has explored to establish a model for predicting the prognosis of urachal cancer. The present study aims to develop and validate nomograms for predicting the prognosis of urachal cancer based on clinicopathological parameters.

Methods

Based on the data from the Surveillance, Epidemiology, and End Results database, 445 patients diagnosed with urachal cancer between 1975 and 2018 were identified as training and internal validation cohort; 84 patients diagnosed as urachal cancer from 2001 to 2020 in two medical centers were collected as external validation cohort. Nomograms were developed using a multivariate Cox proportional hazards regression analysis in the training cohort, and their performance was evaluated in terms of its discriminative ability, calibration, and clinical usefulness by statistical analysis.

Results

Three nomograms based on tumor–node–metastasis (TNM), Sheldon and Mayo staging system were developed for predicting cancer-specific survival (CSS) of urachal cancer; these nomograms all showed similar calibration and discrimination ability. Further internal (c-index 0.78) and external (c-index 0.81) validation suggested that Sheldon model had superior discrimination and calibration ability in predicting CSS than the other two models. Moreover, we found that the Sheldon model was able to successfully classify patients into different risk of mortality both in internal and external validation cohorts. Decision curve analysis proved that the nomogram was clinically useful and applicable.

Conclusions

The nomogram model with Sheldon staging system was recommended for predicting the prognosis of urachal cancer. The proposed nomograms have promising clinical applicability to help clinicians on individualized patient counseling, decision-making, and clinical trial designing.

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.

A rare case of urachal adenocarcinoma with bone marrow metastasis

Urachal cancer is a rare and aggressive cancer that often presents in advanced stages. Given the rarity of this malignancy, medical case studies provide one of the few sources of literature available through which clinicians can guide medical management. Surgery is widely considered to be the mainstay of therapy when disease is localised and surgically resectable, therefore most current case studies on urachal cancer focus on surgical management, occasionally with adjuvant chemotherapy. However, few case studies discuss chemotherapy alone in the treatment of metastatic disease. Most studies indicate a median overall survival between 12 and 24 months for metastatic urachal adenocarcinoma. Bone marrow metastasis of solid tumours, when considered alone, portends a poor prognosis. The patient in this case study represents a rare case of stage IV urachal adenocarcinoma metastatic to the bone marrow without progression of disease after 6 months of treatment.

Prevalence of APC and PTEN Alterations in Urachal Cancer

Urachal carcinoma (UrC) is a rare tumor with remarkable histological and molecular similarities to colorectal cancer (CRC). Adenomatous polyposis coli (APC) is the most frequently affected gene in CRC, but the prevalence and significance of its alterations in UrC is poorly understood. In addition, loss of phosphatase and tensin homologue (PTEN) was shown to be associated with therapy resistance in CRC. Our primary aim was to assess specific genetic alterations including APC and PTEN in a large series of UrC samples in order to identify clinically significant genomic alterations. We analyzed a total of 40 UrC cases. Targeted 5-gene (APC, PTEN, DICER1, PRKAR1A, TSHR, WRN) panel sequencing was performed on the Illumina MiSeq platform (n = 34). In addition, ß-catenin (n = 38) and PTEN (n = 30) expressions were assessed by immunohistochemistry. APC and PTEN genes were affected in 15% (5/34) and 6% (2/34) of cases. Two of five APC alterations (p.Y1075*, p.K1199*) were truncating pathogenic mutations. One of the two PTEN variants was a pathogenic frameshift insertion (p.C211fs). In 29% (11/38) of samples, at least some weak nuclear ß-catenin immunostaining was detected and PTEN loss was observed in 20% (6/30) of samples. The low prevalence of APC mutations in UrC represents a characteristic difference to CRC. Based on APC and ß-catenin results, the Wnt pathway seems to be rarely affected in UrC. Considering the formerly described involvement of PTEN protein loss in anti-EGFR therapy-resistance its immunohistochemical testing may have therapeutic relevance.

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.

[Urachal Cancer: an update of current molecular findings]

BACKGROUND

Urachal cancer is a rare type of cancer, often following a clinically aggressive course. Due to its rarity, knowledge about its molecular background is still limited. In addition, no sufficiently reliable diagnostic markers are available.

OBJECTIVES

The aim of the present study is to give an overview of our recent molecular projects on urachal cancer and to connect it with current literature in the field.

MATERIALS AND METHODS

Three projects are introduced. The first project identified and validated diagnostic biomarkers in urachal adenocarcinomas compared to colorectal adenocarcinomas and primary adenocarcinomas of the bladder using various proteomic methods. In the second project, the most relevant differential diagnostic markers between urachal adenocarcinomas and colorectal adenocarcinomas compared to normal tissue (urachal remnants) were determined by analyzing a miRNA panel. Sequence analyses were performed in the third project. The focus was on molecular differences to colorectal adenocarcinomas and urothelial carcinomas.

RESULTS AND CONCLUSIONS

We detected potential biomarker candidates for the immunohistochemical differential-diagnosis and generated a miRNA-based diagnostic scoring system with a potentially high differential-diagnostic significance. The sequence analyses data confirm the molecular autonomy of the urachal adenocarcinomas compared to other entities.

Primary adenocarcinoma of the bladder lacks mismatch repair deficiency and demonstrates PD-L1 expression in tumor-infiltrating immune cells, with implications in both diagnosis and therapeutics

Primary adenocarcinoma of the bladder is a rare and highly aggressive disease with no standard therapy. Effectiveness of immune checkpoint blockade in bladder adenocarcinoma is unknown due to lack of clinical trials. Due to the disease rarity, the rate of PD-L1 expression and DNA mismatch repair deficiency is largely unknown. In this study, we examined PD-L1 expression in 56 cases of bladder adenocarcinoma and mismatch repair protein expression in 42 cases of bladder adenocarcinoma using immunohistochemistry. Mismatch repair protein expression was uniformly intact in all cases of bladder adenocarcinoma, in comparison with 19% of advanced colorectal adenocarcinoma being mismatch repair deficient. This finding indicates that mismatch repair proteins may be combined with β-catenin and GATA-3 to create an immunostaining panel which, in addition to clinical studies, can aid in distinguishing bladder adenocarcinoma from secondary involvement by colorectal carcinoma. 4% of cases were found to overexpress PD-L1 in tumor cells while approximately a third of cases were found to display PD-L1 expression in tumor-infiltrating immune cells. These results indicate hypermutators are likely rare in bladder adenocarcinoma, yet 20-30% of the patients may be eligible for immune checkpoint blockade therapy.

Case Report: Bladder adenocarcinoma: primary or urachal?

Background: Bladder adenocarcinoma (AC) is a scarce histological variant and there are few studies on its proper management. No previous case reports present the management of a urachal tumor and the incidental finding of bladder adenocarcinoma.

Clinical case: We present the case of a young woman with nonspecific symptoms, who presented with a prior history of dysuria, bladder tenesmus, suprapubic pain and urinary urgency for one year, which had been treated as recurrent urinary tract infection. A partial cystectomy plus extended lymphadenectomy was scheduled. We found a bladder tumor with characteristics of a urachal tumor and the pathological report indicated a primary bladder AC. The patient had a complete recovery at one year of follow-up.

Conclusions: A patient can present with a tumor with urachal characteristics; however, the pathology report can show primary AC. The decision to perform partial cystectomy was an appropriate option for the location of this tumor, with optimal surgical results. Still, a long-term follow-up is necessary. More specific management guidelines are required for the treatment of AC.

Urachal cancer-current concepts of a rare cancer

Urachal cancer is a rare but aggressive disease. In addition to the non-glandular tumors, non-cystic urachal adenocarcinomas are nowadays distinguished from the primary cystic variant. (Immunohistochemical) markers are only of minor differential diagnostic value and, therefore, the diagnosis is primarily established in a multidisciplinary approach. The non-cystic variant accounts for the majority of cases (83%), is more common in men (63%), shows a median age at diagnosis of 51 years and has a 5-year survival rate of about 50%. In organ-confined disease, usually a partial cystectomy of the tumor in the bladder dome, including the median umbilical ligament and umbilicus, is performed. In advanced stages, systemic therapy is needed while 5‑fuorouracil (5-FU) containing regimes have been shown to be more effective. Due to the rarity of the tumor, targeted therapy approaches based on a biological rationale are becoming increasingly relevant. As molecular data are still sparse, we compiled and analyzed the largest urachal cancer cohort to date. In 31% of the cases, MAPK-/PI3K signaling pathway alterations were detected (especially in K-/NRAS) with implications for anti-EGFR therapy approaches. Further potentially therapeutic alterations were detected in FGFR1, MET, PDGFRA, and erbB2/HER2. Additionally, PD-L1 tumor cell expression (clone: 22C3) was demonstrated in 16% of cases, therefore making anti-PD-1/PD-L1 immuno-oncological approaches worth considering despite the absence of mismatch repair deficiency (MMR-d) and/or high microsatellite instability (MSI-h). Finally, urachal adenocarcinomas seem to be a distinct entity on the molecular level with closer resemblance to colorectal adenocarcinomas than to urothelial carcinomas.

Urachal Mucinous Cystic Tumor of Low Malignant Potential with Concurrent Sigmoid Colon Adenocarcinoma

Urachal mucinous tumors are rare neoplasms with behaviour that can range from relatively benign to malignancy that can spread distantly or throughout the peritoneum as pseudomyxoma peritonei or peritoneal carcinomatosis. Here we describe a unique case of urachal mucinous cystic tumor of low malignant potential confined to an intact cyst at the dome of the urinary bladder, without rupture or peritoneal spread. The urachal mucinous tumor was an incidental finding on a staging CT scan performed for sigmoid colon adenocarcinoma. We believe that this case illustrates a potential diagnostic pitfall which could have prognostic and therapeutic implications. Due to the intestinal phenotype of these neoplasms, a urachal tumor of low malignant potential could be mistaken for metastatic spread from a colonic adenocarcinoma in the rare situation such as this case, where the two neoplasms occur concurrently.

[Predictive biomarkers in oncologic uropathology]

BACKGROUND

Tumors of the genitourinary system are common. In recent years, our understanding of their molecular background and therefore the number of potential predictive biomarkers has massively increased.

OBJECTIVES

The aim of the current work is to give an overview of recent (molecular) developments and predictive biomarkers in urologic oncology and to give a perspective of what might become relevant in the future of the field.

MATERIAL AND METHODS

We considered the recent literature and study data and combined it with our own expertise in tumors of the urinary system, kidneys, and prostate.

RESULTS AND CONCLUSIONS

The molecular subtypes of muscle-invasive urothelial bladder cancer (MIBC) hold a predictive and prognostic significance and correlate with clinicopathological features. Immune therapy with checkpoint inhibitors (CPI) has a major role in urothelial carcinoma (UC), but also in renal cell carcinoma and a subgroup of prostate cancers. The first-line use in UC is restricted to PD-L1-"positive" cases (≥IC2/3, CPS ≥ 10). Further predictive markers are currently under evaluation, while the predictive significance of tumor mutational burden (TMB) is under debate. In addition to a subgroup of renal cell carcinomas, a subgroup of prostate carcinomas with alterations in the DNA repair system might benefit from a customized therapy approach (PARP inhibitors, platin-containing chemotherapy). The multitude of potentially therapy-relevant molecular alterations and related predictive biomarkers calls for the implementation of sophisticated molecular analyses in daily routine. This will lead to an even more rapid dynamic in the field of genitourinary pathology.

[Urachal cancer - current concepts of a rare cancer (German version)]

Urachal cancer is a rare but aggressive disease. In addition to the non-glandular tumors, non-cystic urachal adenocarcinomas are nowadays distinguished from the primary cystic variant. (Immunohistochemical) markers are only of minor differential diagnostic value and, therefore, the diagnosis is primarily established in a multidisciplinary approach. The non-cystic variant accounts for the majority of cases (83%), is more common in men (63%), shows a median age at diagnosis of 51 years and has a 5-year survival rate of about 50%. In organ-confined disease, usually a partial cystectomy of the tumor in the bladder dome, including the median umbilical ligament and umbilicus, is performed. In advanced stages, systemic therapy is needed while 5‑fuorouracil (5-FU) containing regimes have been shown to be more effective. Due to the rarity of the tumor, targeted therapy approaches based on a biological rationale are becoming increasingly relevant. As molecular data are still sparse, we compiled and analyzed the largest urachal cancer cohort to date. In 31% of the cases, MAPK-/PI3K signaling pathway alterations were detected (especially in K-/NRAS) with implications for anti-EGFR therapy approaches. Further potentially therapeutic alterations were detected in FGFR1, MET, PDGFRA, and erbB2/HER2. Additionally, PD-L1 tumor cell expression (clone: 22C3) was demonstrated in 16% of cases, therefore making anti-PD-1/PD-L1 immuno-oncological approaches worth considering despite the absence of mismatch repair deficiency (MMR-d) and/or high microsatellite instability (MSI-h). Finally, urachal adenocarcinomas seem to be a distinct entity on the molecular level with closer resemblance to colorectal adenocarcinomas than to urothelial carcinomas.