Clear Cell Adenocarcinoma of Urethra: Clinical and Pathologic Implications and Characterization of Molecular Aberrations

Two rare cases of primary clear cell adenocarcinoma of the urethra: clinical experience, case report and literature review

Background

Primary clear cell adenocarcinoma of the urethra (CCAU) is a kind of extremely rare genitourinary cancer. Despite the similarity in the clinical manifestations of these reported cases, diagnosis and determination of standard therapy remain challenging due to the rarity of findings and similarity with other urethral tumors.

Case presentation

Herein, we reported two cases of CCAU with the same chief complaint of hematuria: a 71-year-old female and a 66-year-old male. The male patient reported concomitant symptoms of frequent and painful urination. CT scans show abnormal enhancements. After a cystoscopy examination, both patients are diagnosed with malignant urethral tumors. Surgical resections and additional pathological examinations support the diagnosis of CCAU (palliative resection for case 1 and transurethral resection for case 2). Case 1 undergone progression 6 months after initial treatment with transurethral resection and chemotherapy with a 15-month overall survival. In contrast, the prognosis of case 2 remained uneventful 10 months after surgery without recurrence. After presenting our cases, we launched a literature review that included 23 articles and 33 cases of CCAU to summarize the characteristics of the disease.

Conclusion

Primary clear cell adenocarcinoma of the urethra is a rare malignant urethral tumor with controversial histological origins. Primary symptoms include hematuria and changes in voiding habits. Middle-aged and elderly females are more susceptible to primary clear-cell adenocarcinoma of the urethra. Unfortunately, it is difficult to differentiate primary clear-cell adenocarcinoma of the urethra from other urethral tumors due to similar clinical features. However, imaging tools such as CT, MRI, and cystoscopy are adjunctive in confirming diagnoses. Even though surgical resection is the primary treatment to relieve clinical symptoms, prevent recurrence, and confirm diagnosis, no standard surgical protocol is available. The therapeutic effect of postoperative adjuvant therapies remains unclear. Future investigations on CCAU are necessary to advance clinical knowledge and to provide treatment guidance.

Urethral clear cell adenocarcinoma in an adult female: A rare case report

Clear cell adenocarcinoma of the urethra is an extremely rare malignancy with a poor outcome, mainly affecting females in old age. We present the case of a 42-year-old female patient who presented with progressively worsening lower urinary tract symptoms, leading to a cystoscopy-guided core needle biopsy diagnosis of clear cell adenocarcinoma of the urethra. We will mainly discuss the cross-sectional imaging and pathological aspects of the case.

The L-type calcium channel CaV1.3: A potential target for cancer therapy

Cancer remains a prominent cause to life expectancy, and targeted cancer therapy stands as a pivotal approach in contemporary therapy. Calcium (Ca2+) signalling plays a multifaceted role in cancer progression, such as proliferation, invasion and distant metastasis. Otherwise, it also exerts an important influence on the efficacy of clinical treatment, including cancer therapy resistance. In this review we discuss the role of the L-type calcium channel CaV1.3 (calcium voltage-gated channel subunit alpha1 D) in different types of cancers, highlighting its potential as a therapeutic target for certain cancer types. The development of selective blockers of the CaV1.3 channel has been of great interest and is expected to be a new option for the treatment of cancers such as prostate cancer and endometrial cancer. We present the pharmacological properties of CaV1.3 and the current status of selective blocker development, and analyse the challenges and possible directions for breakthroughs in the development of tailored medicines.

Association between CACNA1D polymorphisms and hypospadias in a southern Chinese population

BACKGROUND

Hypospadias is a congenital genitourinary malformation, with the etiology remaining complex and poorly understood. Despite several genes have been identified to be associated with the risk of hypospadias, current understanding of the susceptibility loci for hypospadias yet remained largely improved. The CACNA1D gene encodes calcium voltage-gated channel subunit alpha 1d and may be involved in androgen signaling. However, the genetic susceptibility of CACNA1D associated with hypospadias has yet been addressed.

OBJECTIVE

To evaluate the association between CACNA1D polymorphisms and the susceptibility to hypospadias.

METHODS

In this study, we accessed the association between two potential regulatory SNPs (rs3774491 and rs898415) within CACNA1D and hypospadias in a cohort of southern Chinese population which comprised of 740 cases and 948 healthy individuals. Both SNP and haplotypic associations were evaluated. Bioinformatic analysis of the regulatory abilities of the CACNA1D SNPs were carried out by utilizing public ChIP-seq and DNase-seq data. The expression of Cacna1d in mouse external genitalia and testis was evaluated by qPCR.

RESULTS

We found that the allele C in rs3774491 and allele G in rs898415 were significantly associated with an increased risk of hypospadias, especially for proximal hypospadias. Further model-based genotypic analyses showed that these association were prominent in additive model and recessive models. Bioinformatic analyses indicated that both SNPs were colocalized with DNase and multiple histone marker across multiple tissues, suggesting the regulatory potentials for these variants. Cacna1d is detectable in both testis and external genitalia of mouse, but the expression level was more prominent in testis than that in external genitalia, suggesting tissue-specific differences in its expression.

CONCLUSION

Our findings provide evidence for CACNA1D as a novel predisposing gene for hypospadias, shedding new light on the genetic basis of malformation of urinary tract. Further investigations are warranted to elucidate the functional implication of CACNA1D underlying the development of hypospadias.

LEVEL OF EVIDENCE

N/A.