Malignant urachal lesions

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.

Diagnostic Approach to and Differential Diagnosis of Clear Cell and Glandular Lesions of the Lower Urinary Tract

CONTEXT.—

A variety of glandular and clear cell lesions may be seen in the urinary bladder and/or urethra, ranging from benign to malignant primary and secondary tumors. Lesions with no malignant potential include reactive processes, such as nephrogenic metaplasia, and may show similar morphologic features as an infiltrative neoplasm, particularly in small biopsies. Similarly, ectopic tissues of Müllerian origin may be seen in the lower urinary tract, and their distinction from a true glandular neoplasm is essential to avoid overtreatment. A wide variety of primary and secondary malignant tumors exist with varying degrees of glandular and clear cell features. Therefore, surgical pathologists must be aware of the full scope of possible lesions to avoid misdiagnosis.

OBJECTIVE.—

To provide a practical framework for approaching the diagnosis of clear cell and glandular lesions of the urinary bladder/urethra and prostate, highlighting the strengths and limitations of various diagnostic features and ancillary tests.

DATA SOURCES.—

A review of the current literature was performed to obtain data regarding up-to-date diagnostic features and ancillary studies.

CONCLUSIONS.—

In summary, distinct morphologic and immunohistochemical features and clinical and radiologic correlation are essential to establish an accurate diagnosis when such cases with glandular and clear features are encountered in the lower urinary tract.

Primary urachal adenocarcinoma: Case report

INTRODUCTION AND IMPORTANCE

Primary urachal adenocarcinoma (PUA) is a rare form of cancer that arises from the urachus, a vestigial remnant of the allantois and cloaca during embryonic development. The exact pathogenesis of PUA is not well understood, but it is believed to arise from glandular epithelium remnants within the urachus. The rarity of this type of cancer makes it difficult to comprehensively study its epidemiology.

CASE PRESENTATION

This case report describes a 47-year-old male patient who presented with intermittent painless hematuria and fatigue for two months. Cystoscopy showed a single growth at the dome of the urinary bladder, and abdominopelvic CT scan with contrast revealed a 3*2 cm enhancing growth at the dome of the bladder suspicious of urachal origin tumor. The patient was diagnosed with urachal adenocarcinoma (PT2) after pathological examination. The patient underwent partial cystectomy and umbilicectomy.

CLINICAL DISCUSSION

Patients with PUA often present with nonspecific symptoms that can delay the diagnosis. The most common symptom is hematuria, which is present in approximately two-thirds of the patients. The diagnosis of PUA is challenging and relies on a combination of clinical presentation, imaging, and histopathological examination.

CONCLUSION

The mainstay of treatment for PUA is surgical resection, which may include partial cystectomy or radical cystectomy with en bloc resection of the urachus and umbilicus. It is esential to report all cases of primary urachal adenocrcinoma.

Rare case of enteric type of urachal adenocarcinoma: A case report

Urachal adenocarcinomas, constituting 10 % of bladder adenocarcinomas, pose a significant challenge with limited literature. A 43-year-old male presented with haematuria and abdominal pain, leading to surgical intervention for a 13 cm pelvic tumor. Histopathology identified an intestinal-type primary urachal adenocarcinoma, staged as IIIA, no recurrence on follow-up. Early detection is crucial for improved outcomes in these rare malignancies. While surgery remains the primary treatment, outcomes vary, emphasizing the need for research on standardized protocols. Enhanced awareness and interdisciplinary collaboration are vital for effective management. Comprehensive guidelines are essential for optimizing patient prognoses in urachal adenocarcinomas.

[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.

Cytoreduction surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) as treatment choice of metastatic Urachal carcinoma

INTRODUCTION

Urachal carcinoma accounts for approximately 0.01 % of all adult malignancies and 1 % of bladder cancers. Its prognosis remains poor, with a 5-year overall survival rate of less than 50 %.

PRESENTATION OF CASE

A 51-years-old black female, affected by peritoneal malignancies from urachal carcinoma, underwent multiple surgical cytoreduction (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) with different chemotherapy regimen, alternating with intravenous chemotherapy. Thirty-two months recurrence-free survival was registered, and overall survival was more than 5 years.

DISCUSSION

Our case suggests the importance of rigorous follow-up with both tumor marker testing (CEA) and imaging studies. Optimal debulking surgery plays a pivotal role in controlling primary and recurrent disease. The use of combined intraperitoneal and intravenous chemotherapy may have contributed to her long-term survival.

CONCLUSION

CRS and HIPEC combined with intravenous chemotherapy may be potential candidates for treating patients with urachal carcinoma with peritoneal metastases. Our patient is a challenging case in daily surgical practice.

Case report: Urachal perivascular epithelioid cell tumor

Background

Urachal tumors are rare in clinical practice, among which urachal adenocarcinoma is the most common. In this study, we report a rare case of urachal perivascular epithelioid cell tumor to improve our understanding of the disease.

Case presentation

A 26-year-old male patient was hospitalized for lower abdominal pain. The US showed a hypoechoic mass measuring 26mm × 18mm in the superior aspect of the bladder. MRI showed an irregular mass located anterior to the bladder roof, near the midline. The tumor exhibited hypointense on T1WI and heterogeneous hyperintense on T2WI. Additionally, contrast-enhanced T1-weighted imaging revealed obvious ring enhancement of the tumor. The patient underwent surgical resection of the urachal tumor, with subsequent pathological examination revealing a diagnosis of urachal PEComa. Following surgery, the patient underwent regular follow-up assessments, with no evidence of recurrence or metastasis observed after three and a half years.

Conclusions

Urachal PEComa is a rare mesenchymal tumor that presents challenges in diagnosis through imaging and clinical symptoms. Definitive diagnosis relies on pathological and immunohistochemical analysis. Due to the rarity of urachal PEComa, prognosis assessment necessitates long-term follow-up and evaluation of more cases.

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.

A remnant never forgotten: the utility of circulating tumor DNA in treatment guidance of urachal cancer

Urachal cancer is a rare malignancy of the urachus that is treated with surgical resection if localized and systemic chemotherapy for metastatic disease. Circulating tumor DNA (ctDNA) is a single-stranded or double-stranded DNA released by tumor cells into the blood and harbored the mutations of the original tumor, shedding new light on molecular diagnosis and monitoring of cancer. We report a case of resected localized urachal cancer with clear surgical margins and negative lymph node dissection but elevated ctDNA that progressed to metastatic disease. We also highlight the possibility of using ctDNA levels to assist in adjuvant therapy.

The Management of a Case With Mucin-Producing Adenocarcinoma Originating From the Urachus

Urachal cancer is a rare and aggressive type of cancer, frequently characterized by a lack of prominent symptoms. We herein report a case of a 50-year-old female with mucin-producing adenocarcinoma originating from the urachus who underwent partial cystectomy and the patient remains disease-free for 30 months after treatment.

Relapsed urachal carcinoma responding to first-line chemotherapy with capecitabine-oxaliplatin plus bevacizumab

Introduction

Advanced urachal carcinoma has a poor prognosis; however, a standard systemic treatment has not been established. We treated a patient with relapsed urachal carcinoma with capecitabine-oxaliplatin plus bevacizumab, a standard regimen for colon cancer, and obtained favorable responses.

Case presentation

A 47-year-old woman presented with hematuria. Under the diagnosis of non-metastatic urachal carcinoma, an extended partial cystectomy was performed. Histopathological examination revealed adenocarcinoma with negative surgical margins and lymph nodes. Thirty-two months postoperatively, lung metastases and local recurrence were confirmed, along with elevated carcinoembryonic antigen levels, and nine chemotherapy cycles were administered. Subsequently, the recurrent lesion regressed, and tumor marker levels normalized. Fourteen months after treatment discontinuation, the disease remained stable without progression.

Conclusion

This is the first report of advanced urachal carcinoma treated with capecitabine-oxaliplatin plus bevacizumab, demonstrating the potential of this treatment as first-line chemotherapy for this disease.

TNM-Based Head-to-Head Comparison of Urachal Carcinoma and Urothelial Bladder Cancer: Stage-Matched Analysis of a Large Multicenter National Cohort

PURPOSE

Outcome analysis of urachal cancer (UraC) is limited due to the scarcity of cases and different staging methods compared to urothelial bladder cancer (UroBC). We attempted to assess survival outcomes of UraC and compare to UroBC after stage-matched analyses.

MATERIALS AND METHODS

Total 203 UraC patients from a multicenter database and 373 UroBC patients in single institution from 2000 to 2018 were enrolled (median follow-up, 32 months). Sheldon stage conversion to corresponding TNM staging for UraC was conducted for head-to-head comparison to UroBC. Perioperative clinical variables and pathological results were recorded. Stage-matched analyses for survival by stage were conducted.

RESULTS

UraC patients were younger (mean age, 54 vs. 67 years; p < 0.001), with 163 patients (80.3%) receiving partial cystectomy and 23 patients (11.3%) radical cystectomy. UraC was more likely to harbor ≥ pT3a tumors (78.8% vs. 41.8%). While 5-year recurrence-free survival, cancer-specific survival (CSS) and overall survival were comparable between two groups (63.4%, 67%, and 62.1% in UraC and 61.5%, 75.9%, and 67.8% in UroBC, respectively), generally favorable prognosis for UraC in lower stages (pT1-2) but unfavorable outcomes in higher stages (pT4) compared to UroBC was observed, although only 5-year CSS in ≥ pT4 showed statistical significance (p=0.028). Body mass index (hazard ratio [HR], 0.929), diabetes mellitus (HR, 1.921), pathologic T category (HR, 3.846), and lymphovascular invasion (HR, 1.993) were predictors of CSS for all patients.

CONCLUSION

Despite differing histology, UraC has comparable prognosis to UroBC with relatively favorable outcome in low stages but worse prognosis in higher stages. The presented system may be useful for future grading and risk stratification of UraC.

Low-Grade Urachal Cystadenoma With Abundant Calcification Removed Using Robot-Assisted Laparoscopy: A Case Report

Neoplasms of the urachus are an extremely rare entity consisting of incompletely obliterated tissue of the urachal canal during embryonic development, which sometimes remains into adulthood in the urinary bladder. The treatment of choice for these entities is surgical excision, which maximizes patient survival should the lesion prove to be malignant. In this case, we describe a 57-year-old female who presented with a one-year history of left lower quadrant pain. The patient underwent robot-assisted surgery to remove the mass, bladder dome, and median longitudinal ligament en bloc without evidence of recurrence to date.

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.

Modern methods in managing urachal adenocarcinoma

Objectives

We sought to evaluate modern diagnostic and treatment options for urachal adenocarcinoma (UAC) and to provide clarity regarding the available options and their outcomes for this poorly understood yet damaging disease.

Material and methods

We conducted a systematic literature search in PubMed and Medline focusing on updated management of UAC.

Results

Surgical intervention continues to be the mainstay of treatment for localized UAC. However, with the increased availability of molecular and genetic profiling, chemotherapy has consistently demonstrated promising response rates and survival outcomes, especially for a disease that commonly presents in a metastatic stage. The role of checkpoint inhibitors remains under investigation. Cross-sectional imaging is vital during postoperative surveillance. However, there may also be a role for the adoption of cystoscopy to detect bladder recurrence.

Conclusions

Although the importance of surgical resection remains unchanged, improved survival outcomes with chemotherapy have been found in small retrospective studies. Randomized trial data are required to further assess the influence of systemic treatment as a primary or adjuvant therapy. Moreover, a stringent follow-up regimen incorporating evaluation for distant and local recurrence of UAC must be evaluated and adopted.

Peritoneal Surface Malignancies Originating From Urachal Carcinoma: Case Reports and Review of the Literature

Urachal carcinoma (UC) is a rare and aggressive tumor arising from the urachal remnants, with the potential for peritoneal dissemination. Patients diagnosed with UC often have a poor prognosis. To date, there is no standardized treatment. Our objective is to present two cases of patients with peritoneal carcinomatosis (PC) secondary to an UC, who were treated with cytoreductive surgery (CRS) and hyperthermic peroperative intraperitoneal chemotherapy (HIPEC). A review of the literature on CRS and HIPEC in UC suggests CRS and HIPEC to be a safe and viable treatment option. Two patients with PC of UC underwent CRS and HIPEC in our institution. All available data were gathered and reported on. A literary search was carried out to find all available cases of patients with PC secondary to UC treated with CRS and HIPEC. Both patients underwent CRS and HIPEC and are currently free of recurrence. Literature research revealed nine other publications adding up to a total of 68 additional cases. CRS and HIPEC can provide satisfactory long-term oncological outcome with acceptable morbidity and mortality rates in patients with PC of urachal origin. It should be considered as a safe and feasible treatment option with curative potential.

Laparoscopic management of symptomatic urachus remnants in adults: A retrospective study

Aim

To report our experience in the laparoscopic management of symptomatic urachal remnants (URs) in adults.

Patients and Methods

A retrospective study included all patients who underwent laparoscopic excision of URs during the period January 2015-January 2020. The following data were retrieved from the files of the patients: demographic data, clinical presentations, intra-operative findings, the procedure performed, operative details, intraoperative or post-operative complications and follow-up period mentioned in the files for those patients.

Results

The study included 10 patients (four males and six females) with a mean age of 27.8 ± 11.0 years. URs were discovered preoperatively in all patients except one patient who was diagnosed intraoperatively. URs were associated with other pathologies in four patients (40%) that required two simultaneous surgical procedures. Eight patients (80%) presented with simple umbilical discharge and were diagnosed easily by ultrasonography. All patients were managed successfully with laparoscopic excision and umbilical sparing technique. Excision of the dome of the bladder was done on the selective approach to one patient. No patients showed early post-operative complications. Only one patient had stitch sinus 6 months postoperatively due to a concomitant hernia repair rather than due to the excision of the URs.

Conclusions

Laparoscopic excision of symptomatic urachus is a feasible procedure even when the excision of the bladder is required. It could be performed successfully with other pathologies. It is associated with a low incidence of complications. Laparoscopy allows good visualisation and complete excision that leads to almost no recurrence rate.

Urachal carcinoma: The journey so far and the road ahead

Urachal carcinoma, a rare cancer arising from urachus, accounts for about 1% of bladder cancer. The diagnosis at stage I shows about 63% 5-year survival whereas only 8% of the patients at stage IV shows a 5-year survival. Above 90% of urachal carcinomas are adenocarcinomas and most of the urachal carcinoma cases are invasive, showing a high resemblance to adenocarcinoma of various origins, making it hard for a conclusive diagnosis. Even though inconclusive, immunohistochemistry can play a significant role in identifying urachal carcinoma. Most cases show the biomarkers CK20 and CDX2, whereas CK7 and β-catenin are expressed at a lesser frequency. Due to the few cases available, there is a lack of evidence regarding specific markers differentiating urachal carcinoma from colorectal or primary bladder adenocarcinomas. In addition to immunohistochemistry, genomic characterization is emerging to play a role in the classification and treatment of the disease. Urachal carcinoma has been reported to have a molecular level similarity with colorectal malignancies regarding certain gene expressions. The TP53 mutations inactivating the tumor suppressor can probably be explored as a possible target in treating urachal carcinoma. Additionally, certain targets identified in gastric and breast cancer along with anti-HER2 treatment strategies can be explored. Immuno-oncology utilizes immune checkpoint inhibitors for the treatment of MSI-H tumors whereas a combination of tyrosine kinase inhibitors along with immune checkpoint inhibitors are being studied to treat MSI stable tumors. The article is an in-depth overview of urachal carcinoma addressing the current landscape with an emphasis on the future scenario.

[New WHO classification 2022: urinary bladder cancer]

The new World Health Organization (WHO) classification of urogenital tumors is still primarily based on anatomic location, but is also a hierarchical taxonomic classification without separate chapters for tumors of the upper urinary tract and the urethra. It clarifies aspects regarding grading and noninvasive entities. It consolidates the use of the Paris system for urinary cytology as well as various subtypes/special types of neoplasms, and incorporates general concepts of the 5th edition of the WHO blue book. In addition to mesenchymal tumors, well-differentiated neuroendocrine tumors and neuroendocrine carcinomas are addressed in separate chapters. Papillary non-invasive low- and high-grade carcinomas and carcinoma in situ remain, while dysplasia and urothelial proliferation of unknown malignant potential (UPUMP) are no longer treated as separate entities. Former variants of urothelial carcinoma are now called subtypes and aberrant differentiation and special types are more precisely defined.

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.

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.

[A CASE OF PERIVESICAL ABSCESS CAUSED BY MIGRATION OF A FOREIGN BODY FROM THE INTESTINAL TRACT]

A 76-year-old woman was referred to our department because of high fever and bladder irritative symptoms. Computed tomography revealed the presence of a heterogeneous mass with indistinct borders on the left anterior wall of the bladder. The lesion contained a linear hyperdense shadow. We initially suspected malignancy, such as urachal carcinoma or soft-tissue sarcoma. However, upon review of previous computed tomography scans, it was confirmed that the linear hyperdense shadow had migrated from the intestinal tract to the bladder. Considering the possibility of abscess formation caused by a foreign body, we decided to perform a transurethral biopsy. The results of the pathological analysis showed abscess formation. The patient was diagnosed with perivesical abscess caused by accidental ingestion of a fish bone. Following the administration of antibiotics, the lesion markedly shrank. Although it is difficult to distinguish perivesical abscess from malignant disease, invasive treatment can be avoided by appropriate diagnosis based on imaging studies.

An Unusual Case of Urachal Cyst Misdiagnosed as a Paraovarian Cyst: Ultrasound Assessment and Differential Diagnosis

The urachus is an embryologic remnant of the cloaca that usually degenerates after birth, resulting from the obliteration of the allantois, whose role is to connect the bladder to the umbilicus. Incomplete removal of the lumen may give rise to different malformations of the median umbilical ligament after birth. Although in the pediatric population urachus are common, most cases are asymptomatic and may go unrecognized until adulthood and give rise to cysts, rarely reported in the literature. Thus, in this manuscript we present the circumstances of a 43-year-old Romanian woman showing hypogastric pain of moderate intensity for three weeks, radiation in the left lower limb, menstrual cycle abnormalities, and dysmenorrhea. Based on the initial examinations, a paraovarian cyst measuring 80 mm was noted. Through the subsequent magnetic resonance imaging (MRI) conducted, a hypoechoic mass was detected, and the patient underwent a tumorectomy and partial cystectomy. A 9.7/7.5-cm tumor was excised, and the anatomopathological result was urachal mucinous cystadenoma. It came to our attention that relatively scarce data were found in the literature, with only seven studies with the diagnosis of the urachal cyst.

Non-urothelial and urothelial variants of bladder cancer

Non-urothelial bladder cancers make up a rare minority of all genitourinary (GU) tract histologic cancers since urothelial cancer (UC) makes up the most common histologic subtype. Bladder cancer variant histology (BCVH) or urothelial variants also occur rarely though distinction is important given aggressive presentation and natural history. While methods for diagnosis and treatment of typical urothelial cancers (UC) are well-established, there are no clear guidelines with regard to the diagnosis of non-urothelial bladder cancers, which often results in misdiagnosis and treatment delay. This review will focus on the clinicopathologic characteristics of the most common non-urothelial bladder cancers, to be distinguished from bladder cancer variant histology containing a UC component. The role of genomics in non-urothelial bladder cancers is evolving and the use of biomarkers to guide the diagnosis and treatment of these tumors remains a key area of unmet need. Treatment of these cancers will be discussed in a companion review.

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.

Incidental findings on prostate MRI: a close look at the field of view in this anatomical region

Magnetic resonance imaging (MRI) has been widely used as an advanced imaging modality to detect prostate cancer and indicate suspicious areas to guide biopsy procedures. The increasing number of prostate examinations with MRI has provided an opportunity to detect incidental lesions, and some might be very significant to elucidate patient symptoms or occult neoplastic process in the early stages. These incidental lesions might be located in the prostate gland, adjacent tissues, or organs around the prostate gland or out of the genitourinary system. The field of view of prostate MRI includes not only the prostate gland but also other critical pelvic organs in this specific anatomical region. Some of these incidental lesions might cause the same symptoms as prostate cancer and might explain the symptoms of the patient, and some might indicate early cancer stages located outside the prostate. Reporting these lesions might be life-saving by initiating early disease treatment. Awareness of the predicted locations of congenital anomalies would also be beneficial for the radiologists to mention these incidental findings.

Primary urachal signet ring cell carcinoma: A case report

Urachal signet ring cell carcinoma is a kind of rare but aggressive tumor, and a few cases have been reported previously. A 49-year-old male patient with primary complaints of increased frequency of urination, urodynia, and hematuria was diagnosed to have primary urachal signet ring cell carcinoma by our department. Multiple metastases were found in the sigmoid colon, terminal ileum, mesentery, and peritoneum during the operation, and palliative surgery involving partial cystectomy with en bloc resection of the urachus was then performed. A chemotherapy regimen of fluorouracil combined with cisplatin was made for this case. In addition, this patient also received anlotinib for targeted therapy. So far, this patient has done well on regular follow-up for 6 months and is in stable condition. We reported this additional urachal signet ring cell carcinoma case and conducted a literature review to strengthen our cognition of this disease.

Urachal carcinoma: A novel staging system utilizing the National Cancer Database

BACKGROUND

Urachal carcinoma (UrC) is a rare, aggressive cancer with a poor prognosis that is frequently diagnosed in advanced stages. Due to its rarity, the current staging systems, namely Sheldon, Mayo, and Ontario were established based on relatively small patient cohorts, necessitating further validation. We used a large patient population from the National Cancer Database to model a novel staging system based on the Tumor (T), Node(N), and Metastasis (M) (TNM) staging system and compared it to established staging systems.

METHODS

We identified patients diagnosed with UrC between the years of 2004-2016. To determine median overall survival (OS), a Kaplan-Meier (KM) curve was generated using the Sheldon, Mayo, Ontario, and TNM staging system. A cox proportional-hazards regression model was developed to highlight predictors of overall survival.

RESULTS

A total of 626 patients were included in the analysis. The OS for the entire cohort was 58.2 months (50.1-67.8) with survival rates at 12, 24, and 60 months of 83%, 70%, and 49%, respectively (p < 0.0001). As compared to the Sheldon, Mayo, and Ontario staging system, our TNM staging system had a more balanced sample and survival distribution per stage and no overlap among stages on KM survival curves. The Mayo, Ontario, and TNM staging systems were more accurate in terms of stage-survival correlation than the Sheldon staging system (p < 0.05 for all stages).

CONCLUSIONS

The proposed novel TNM staging system for UrC has a more balanced sample distribution and a more accurate stage-survival correlation than the traditional Mayo, Sheldon, and Ontario staging systems. It is clinically applicable and enables better risk stratification, prognosis, and therapeutic decision-making.

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.

Distinct Gene Mutations Are Associated With Clinicopathologic Features in Urachal Carcinoma

OBJECTIVES

To investigate the gene mutational profile of urachal carcinoma in correlation with its clinicopathologic features.

METHODS

We analyzed genetic mutations in 30 cases of urachal carcinoma by next-generation sequencing (NGS) test. Histologic slides and clinical data were reviewed.

RESULTS

The patients included 21 men and 9 women, with a mean age of 53 years (range, 24-75 years). The urachal carcinomas included mucinous (11), enteric (10), signet ring cell (8), and high-grade neuroendocrine (1) subtypes. Targeted NGS analysis demonstrated genetic mutations in all the urachal tumors (mean, 2; range, 1-4). TP53 was the most mutated gene (25), followed by KRAS (9) and GNAS (8) genes. TP53 mutations were more common in the signet ring cell subtype (7/8), and GNAS mutations were present only in the mucinous (5/11) and signet ring cell subtypes (3/8) but not in the enteric subtype (0/10). KRAS mutations were significantly associated with cancer stage IV (P = .02) and younger patient age (P = .046). Furthermore, the presence of KRAS mutations in urachal carcinoma portended a poorer overall survival (P = .006).

CONCLUSIONS

Urachal carcinoma demonstrates frequent gene mutations that are associated with distinct clinicopathologic features. Gene mutation may underlie the development and progression of this aggressive disease.

Atypical Presentation of a Urachal Carcinoma as an Enterocutaneous Fistula

Urachal carcinoma is a rare and aggressive tumor, involving the urachus and the bladder. Symptoms of urachal carcinoma usually appear at later stages of the disease; therefore, these tumors are diagnosed in advanced stages, providing limited options for curative treatment. We report the clinical case of a 60-year-old man with a urachal carcinoma which presented as a mass of the abdominal wall invading the transverse colon, creating an enterocutaneous fistula. The patient underwent an en-bloc resection of the mass, segmentary resection of the transverse colon, and partial cystectomy.

A Rare Case of Urachal Cyst in a Patient With Uterine Fibroids

A 41-year-old woman presented to the emergency department with pain in her abdomen during menstruation. On examination, we detected a cystic lump in the midline, just below the umbilicus. Ultrasonography of the whole abdomen was suggestive of uterine fibroids with a probable mesenteric cyst. Computed tomography of the abdomen confirmed an otherwise asymptomatic, silent, urachal cyst connected to the umbilicus and urinary bladder by obliterated bands. The cyst was explored and removed surgically under combined spinal-epidural anesthesia, following a single-staged approach. A total abdominal hysterectomy with bilateral salpingo-oophorectomy was subsequently performed. Urachal cysts are rare congenital anomalies. Any unexpected finding on clinical examination should alert clinicians for further evaluation and treatment.

A rare case of urachal carcinoma with multiple lung metastasis that required differentiation from primary lung carcinoma

Urachal carcinoma is a rare malignancy of all bladder carcinomas. Metastatic lung tumours showing multiple nodules are rare without a local recurrence. We describe a case of multiple metastatic lung cancer from urachal carcinoma that required differentiation from primary lung cancer.

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.

Small Bowel Obstruction Due to Metastatic Urachal Adenocarcinoma: A Rare Presentation

Urachal adenocarcinoma is a rare but highly malignant epithelial cancer that accounts for <1% of all bladder malignancies and commonly presents with hematuria. We report a case of metastatic urachal adenocarcinoma presenting as bowel obstruction. A 54-year-old male patient with a history of alcohol abuse presented to the emergency with acute-onset, diffuse, cramping abdominal pain, worst in the epigastrium and lasting one day. Abdominal examination revealed moderate guarding and generalized tenderness with hypoactive bowel sounds. Imaging confirmed an evolving small bowel obstruction and a urachal remnant with a superimposed mass lesion. The patient underwent an exploratory laparotomy and a high-grade small bowel obstruction due to the mass was identified. An intraoperative frozen section identified adenocarcinoma. A biopsy of the urachal mass confirmed urachal adenocarcinoma. The final diagnosis was moderately differentiated urachal adenocarcinoma. The tumor was deemed unresectable due to the involvement of multiple loops of the small bowel and the mesentery of the small and large bowels. Systemic chemotherapy with 5-fluorouracil (5-FU), leucovorin, and oxaliplatin (modified FOLFOX-6) was initiated. Our patient did not report any prior urinary symptoms or recurrent abdominal pain, which are the common symptoms that urachal adenocarcinoma presents with. Bowel obstruction is a rare presentation of urachal adenocarcinoma since the spread of the disease to the viscera occurs much later in the course. This case report highlights a rare presentation of an even rarer malignancy.

Umbilical sparing robotic partial cystectomy for localized urachal adenocarcinoma: A case report

Urachal adenocarcinoma, the third most common histopathological type of non-urothelial bladder cancer, is often aggressive, presenting in advanced stages. Increased understanding of the embryologic origin of the tumor with concurrent advances in surgical technique have allowed partial cystectomy to become the gold standard of surgical treatment. However, the benefit of en bloc umbilectomy remains questionable. Here we present the diagnosis and management of 67- year old patient diagnosed with mucinous cystadenocarcinoma of the urachus treated with umbilical-sparing robotic partial cystectomy. We also provide a review of the existing literature on this rare tumor and its management.

Two Patients with Urachal Cancer with Multifocal Adenocarcinoma Recurrences in the Urothelium of the Prostatic and Penile Urethra

We report two cases with recurrences of urachal adenocarcinoma (UrAC) in the urethra. Both patients had mucinous UrAC without metastasis, for which they were treated with en-bloc partial cystectomy and umbilectomy. The first patient developed recurrence of UrAC in the distal urethra after 1 yr. Distal urethrectomy revealed multiple additional recurrences in the penile and prostatic urethra. The patient underwent radical cystoprostatectomy with en-bloc urethrectomy. At 5 mo after surgery, liver metastases were found. A search in our institutional database revealed a second patient who developed a solitary recurrence of UrAC in the prostatic urethra 8 yr after partial cystectomy. Radical cystoprostatectomy was performed. The patient subsequently experienced recurring UrAC in the urethra, which were treated with multiple surgeries and radiation. Unfortunately, local tumor control could not be achieved and the patient developed distant metastases 7 yr after cystoprostatectomy. Our two cases and four comparable cases reported in the literature indicate that urothelial spread of UrAC is rare but possible. It remains to be determined if UrAC spreads along the urothelium similar to urothelial cancer or if these multifocal urethral recurrences were the first sign of local metastasis.

Treatment Outcome of Different Chemotherapy in Patients With Relapsed or Metastatic Malignant Urachal Tumor

Background

Malignant urachal tumor is a rare subtype of genitourinary cancer. Our aim was to explore the optimal chemotherapy regimens for relapsed or metastatic urachal carcinoma.

Materials and Methods

We retrospectively enrolled 24 adult patients with relapsed or metastatic urachal carcinoma from January 2014 to September 2020 at Sun Yat-sen University Cancer Center. We summarized the chemotherapy regimens and classified them as fluorouracil based, platinum based, and paclitaxel based. Nine patients received XELOX (capecitabine and oxaliplatin) regimens, seven patients received TX (paclitaxel and capecitabine) regimens, and eight of them received chemotherapy including GP (gemcitabine and cisplatin), TP (paclitaxel and cisplatin), TN (paclitaxel and nedaplatin), and tislelizumab.

Results

The disease control rate was 75%. Among all patients, one patient treated with XELOX achieved partial remission (PR), while 17 patients showed stable disease. The median progression-free survival (PFS) and overall survival (OS) in all treated patients was 7.43 and 29.7 months, respectively. The patients receiving first-line platinum-based chemotherapy presented better PFS than those without platinum (median PFS 8.23 vs. 3.80 months, p = 0.032), but not significant for OS between two groups. There is no significant difference in PFS and OS for fluorouracil-based and paclitaxel-based groups as first-line regimen. Next-generation gene sequencing revealed TP53 mutation and low tumor mutational burden in five out of seven cases.

Conclusion

The platinum-based chemotherapy regimen is effective for relapsed or metastatic urachal carcinoma.

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.

Clinical and Radiological Features of Urachal Carcinoma and Infection

PURPOSE

To explore the clinical and radiological differences between urachal carcinoma and urachal infection.

METHODS

Clinical and imaging information for 13 cases of urachal carcinoma and 14 cases of urachal infection confirmed by pathology were retrospectively analyzed. The size, location, shape, margin, lesion composition, calcification, T1 and T2 signal intensity, peripheral lymph nodes, degree of enhancement, adjacent bladder wall, and apparent diffusion coefficient (ADC) value were examined in both groups, and distinguish features were determined. The student t-test or Mann-Whitney U test was used for quantitative data, and Fisher's exact test was used for qualitative data. Kappa coefficient consistency test was used to evaluate the interobserver agreement.

RESULTS

Sex, hematuria, abdominal pain, calcification, and thickening of adjacent bladder wall can distinguish between urachal carcinoma and urachal infection (p < 0.05). There were no statistical differences in age (p = 0.076), size (p = 0.797), location (p = 0.440), shape (p = 0.449), margin (p = 0.449), lesion composition (p = 0.459), T1 signal intensity (p = 0.196), T2 signal intensity (p = 0.555), peripheral lymph nodes (p = 0.236), degree of enhancements (p = 0.184) and ADC value (p = 0.780) between two groups.

CONCLUSION

The following clinical and imaging features help distinguish urachal carcinoma from urachal infection: sex, hematuria, abdominal pain, calcification, and thickening of the adjacent bladder wall.

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.

Clinical, Pathological, and Prognostic Analysis of Urachal Carcinoma

OBJECTIVE

The aim of this study was to improve understanding the clinical, pathologic, and prognostic features of urachal carcinoma (UrC), a retrospectively descriptive study was done in 2 clinical centers.

METHODS

After excluding the 2 missed patients, the clinical and pathological data of 59 patients with UrC, who were diagnosed or treated at 2 clinical centers between 1986 and 2019, was retrospectively analyzed. SPSS 22.0 (IBM) and GraphPad Prism 8.0.1 were used for statistics and data visualization. Survival data were analyzed by the Kaplan-Meier method and Log-rank tests. Cox proportional hazards regression were performed for find risk factors on predicting the prognosis.

RESULTS

Of all 59 patients, 47 were male and 12 were female. The median age at diagnosis was 51.6 years (range: 22-84 years). Gross hematuria was the most common symptom (79.66%). The majority of urachal neoplasms were adenocarcinomas (94.92%). Forty-two patients (72.41%) underwent extended partial cystectomy with en bloc resection of the entire urachus. The mean follow-up was 52 months (3-277 months). Median overall survival was 52.8 months (4-93 months). The 3-year cancer-specific survival (CSS) rate and 5-year CSS rate were 69.1% and 61.2%. There was no significant difference among localized T stage, tumor histologic grade and surgical procedures in determining prognosis by survival analyze. While patients with high-risk TNM stage (local abdominal metastasis, lymph node metastasis, or distant metastasis) (p = 0.003) and positive surgical margin (p < 0.001) had significantly worse prognosis.

CONCLUSIONS

The results indicate that high-risk TNM stage and positive surgical margin are risk predictors of prognosis. Localized T stage, histologic grade, and surgical procedure cause no significant effect on patient prognosis. The extended partial cystectomy is the recommended surgical approach for patients with UrC. Active multimodal treatments may improve the survival of patients with recurrent and metastatic disease.