Mutational Profile Using Next-Generation Sequencing May Aid in the Diagnosis and Treatment of Urachal Adenocarcinoma

Urachal adenocarcinoma in an adolescent girl: A case report

INTRODUCTION

The urachus is a fetal canal that connects the allantois to the bladder and typically obliterates by the 6th month of gestation. Failure of the urachus to obliterate can result in urachal anomalies, which, in rare cases, may undergo malignant transformation.

CASE PRESENTATION

We present a case of a 13-year-old female who experienced hematuria, dysuria, and abdominal pain persisting for over 4 months. A CT scan revealed a mass extending from the bladder wall, involving an adjacent bowel loop, and associated with intra-abdominal lymphadenopathy. Debulking surgery was performed, and a histopathological examination confirmed the diagnosis of urachal adenocarcinoma.

DISCUSSION

Urachal anomalies are exceedingly rare, with malignancies arising from urachal remnants being even more uncommon. Most patients are diagnosed at advanced stages due to the late onset of symptoms, resulting in a five-year survival rate of approximately 50 %.

CONCLUSION

Urachal adenocarcinoma can occur in children, potentially due to early oncogenesis of urachal cells. It should be considered a significant differential diagnosis in children presenting with recurrent lower abdominal pain and a urachal remnant to facilitate early detection and timely management.

Treatment approaches for urachal cancer: Use of immunotherapy and targeted therapies

Urachal cancer is a rare genitourinary malignancy that arises from the embryologic remnant of the urachus. The malignancy is considered to be aggressive, with no clear consensus on appropriate management for advanced disease. Although traditionally considered to be related to bladder cancer given its embryologic origin, several next generation sequencing studies have revealed the genomic profile of this genitourinary malignancy most closely resembles colorectal cancer. Moreover, these studies have identified potentially actionable mutations including EGFR, KRAS and MET. In addition, recent data suggests that immunotherapy may benefit some patients with advanced urachal cancer. Nonetheless, continued research is warranted to better understand how to treat this rare genitourinary cancer.

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.

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.

Successful treatment of locally advanced urachal adenocarcinoma with peri-operative gemcitabine - cisplatin combination therapy: a case report and perspective on targeted therapies

Urachal adenocarcinoma is a rare cancer and is treated based on the experience from case series and expert opinion as no randomized studies have been performed. This report adds to the current literature the experience of a patient with locally advanced urachal adenocarcinoma who was treated with combination of neoadjuvant gemcitabine/ cisplatin chemotherapy, surgery and adjuvant chemotherapy and has obtained a long recurrence free survival currently for more than 5 years. Although 5-FU-based chemotherapy is favored by many experts in the treatment of metastatic urachal adenocarcinoma, gemcitabine-based regimens have produced partial responses in metastatic disease and have been used in peri-operative treatment with a manageable adverse effect profile. A brief discussion of molecular lesions in urachal carcinomas and of the emerging role of targeted therapies is included in the current report.