Clinical features and treatment of collecting duct carcinoma of the kidney from the korean cancer study group genitourinary and gynecology cancer committee

Cancer subtype identification by multi-omics clustering based on interpretable feature and latent subspace learning

In recent years, multi-omics clustering has become a powerful tool in cancer research, offering a comprehensive perspective on the diverse molecular characteristics inherent to various cancer subtypes. However, most existing multi-omics clustering methods directly integrate heterogeneous features from different omics, which may struggle to deal with the noise or redundancy of multi-omics data and lead to poor clustering results. Therefore, we propose a novel multi-omics clustering method to extract interpretable and discriminative features from various omics before data integration. The clinical information is used to supervise the process of feature extraction based on SHAP (SHapley Additive exPlanation) values. Singular value decomposition (SVD) is then applied to integrate the extracted features of different omics by constructing a latent subspace. Finally, we utilize shared nearest neighbor-based spectral clustering on the latent representation to obtain the clustering result. The proposed method is evaluated on several cancer datasets across three levels of omics, in comparison to several state-of-the-art multi-omics clustering methods. The comparison results demonstrate the superior performance of the proposed method in multi-omics data analysis for cancer subtyping. Additionally, experiments reveal the efficacy of utilizing clinical information based on SHAP values for feature extraction, enhancing the performance of clustering analyses. Moreover, enrichment analysis of the identified gene signatures in different subtypes is also performed to further demonstrate the effectiveness of the proposed method. Availability: The proposed method can be freely accessible at https://github.com/Tianyi-Shi-Tsukuba/Multi-omics-clustering-based-on-SHAP. Data will be made available on request.

A curious case: Concurrent collecting duct renal cell carcinoma and upper tract urothelial carcinoma

A 71-year-old male presented to Urology with three weeks of overt haematuria and increasing lethargy. Contrast-enhanced CT scans revealed an 8 × 6cm partially exophytic lesion in the left kidney's upper pole, extending beyond the capsule and invading the superior cortical vein, accompanied by abnormal retrocrural lymph nodes. Signs of paraneoplastic syndrome prompted a left radical nephrectomy for symptom relief. Histological analysis identified high-grade collecting duct renal carcinoma and invasive urothelial cell carcinoma. Post-surgery, he was referred for oncological treatment but passed away within two months of the initial diagnosis.

Urothelial Carcinoma of the Renal Pelvis with Synchronous Ipsilateral Collecting Duct Carcinoma: Two Case Reports

Synchronous renal malignancies are seldom encountered or diagnosed post-renal resection. A combination of renal cell carcinoma (RCC) and urothelial carcinoma (UC) is most commonly reported. Typically, the RCC subtype is clear-cell RCC; however, a combination of collecting duct carcinoma (CDC) and UC has rarely been reported in the existing literature. Here, we present two cases of synchronous renal malignancy, specifically a combination of CDC and UC, in the ipsilateral kidney.

[Collecting duct carcinoma and renal medullary carcinoma in the age of new therapies]

Collecting duct carcinoma (also known as Bellini tumour) and renal medullary carcinoma are two extremely rare and aggressive renal cancers. They are both less responsive to conventional treatments used in clear cell renal carcinoma. There are very few studies evaluating their optimal management and currently, at the metastatic stage, polychemotherapy based on platinum salts remains the most widely used. The emergence of new treatments such as anti-angiogenic TKIs, immunotherapy or treatments targeting specific genetic abnormalities, opens up a new field of possibilities in the management of these cancers. The evaluation of the response to these treatments is therefore essential. In this article, we will review the status of their management and the various studies that have evaluated recent treatments in these two cancers.

Metastatic Renal Medullary and Collecting Duct Carcinoma in the Era of Antiangiogenic and Immune Checkpoint Inhibitors: A Multicentric Retrospective Study

Collecting duct carcinoma (CDC) and renal medullary carcinoma (RMC) are two rare subtypes of kidney cancer with a poor prognosis in the metastatic setting. Beyond first-line treatment, there are no standard-of-care therapies. This retrospective study assessed the efficacy of treatments after first-line chemotherapy in 57 patients with metastatic (m) CDC (n = 35) or RMC (n = 22) treated between 2010 and 2019 at 11 French centers. The median age was 53 years; overall, 60% (n = 34) of patients were metastatic at diagnosis. After a median follow-up of 13 months, the median overall survival was 12 (95% CI, 11−16) months. All patients received first-line platinum chemotherapy ± bevacizumab, with a median time to progression of 7.27 (95% CI, 7−100 months and an objective response rate (ORR) of 39% (95% CI, 26−52%). Patients received a median of two (1−5) treatment lines. Subsequent treatments included tyrosine kinase inhibitors (n = 12), chemotherapy (n = 34), and checkpoint inhibitors (n = 20), with ORR ranging 10−15% and disease control rates ranging 24−50%. The duration of response for all treatments was ~2 months. Notably, nine patients with CDC were still alive > two years after metastatic diagnosis. Beyond first-line therapy, treatments showed very low antitumor activity in mCDC/RMC. A better understanding of the biology of those rare tumors is urgently needed in order to identify potential targets.

Uncommon malignant renal tumors and atypical presentation of common ones: a guide for radiologists

OBJECTIVE

While the typical imaging features of the more common RCC subtypes have previously been described, they can at times have unusual, but distinguishing features. Rarer renal tumors span a broad range of imaging features, but they may also have characteristic presentations. We review the key imaging features of atypical presentations of malignant renal tumors and uncommon malignant renal tumors.

CONCLUSION

Renal tumors have many different presentation patterns, but knowledge of the distinguishing MR and CT features can help identify both atypical presentation of common malignancies and uncommon renal tumors.

Aggressive co-existence: Collecting duct and clear cell carcinoma in the same kidney

As in every organ, synchronous multiple cancers are rarely encountered in kidneys. In the literature, mostly co-existence of renal cell carcinoma and transitional cell carcinoma was reported. In the literature, the co-existence of collecting duct carcinoma and clear cell carcinoma was described only for a few cases with different patterns. With these two cases, we aimed to present a very rare entity with synchronous existence of clear cell renal cell carcinoma and collecting duct carcinoma in the same kidneys.

Collecting duct carcinoma of the kidney is associated with CDKN2A deletion and SLC family gene up-regulation

The genetic landscape and molecular features of collecting duct carcinoma (CDC) of the kidney remain largely unknown. Herein, we performed whole exome sequencing (WES) and transcriptome sequencing (RNASeq) on 7 CDC samples (CDC1 −7). Among the 7 samples, 4 samples with matched non-tumor tissue were used for copy number analysis by SNP array data. No recurrent somatic SNVs were observed except for MLL, which was found to be mutated (p.V297I and p.F407C) in 2 samples. We identified somatic SNVs in 14 other cancer census genes including: ATM, CREBBP, PRDM1, CBFB, FBXW7, IKZF1, KDR, KRAS, NACA, NF2, NUP98, SS18, TP53, and ZNF521. SNP array data identified a CDKN2A homozygous deletion in 3 samples and SNV analysis showed a non-sense mutation of the CDKN2A gene with unknown somatic status. To estimate the recurrent rate of CDKN2A abnormalities, we performed FISH screening of additional samples and confirmed the frequent loss (62.5%) of CDKN2A expression. Since cisplatin based therapy is the common treatment option for CDC, we investigated the expression of solute carrier (SLC) family transporters and found 45% alteration. In addition, SLC7A11 (cystine transporter, xCT), a cisplatin resistance associated gene, was found to be overexpressed in 4 out of 5 (80%) cases of CDC tumors tested, as compared to matched non-tumor tissue. In summary, our study provides a comprehensive genomic analysis of CDC and identifies potential pathways suitable for targeted therapies.

Non-Clear Cell Renal Cell Carcinoma: Current Management and Best Practice

The treatment of metastatic renal cell carcinoma (mRCC) has evolved markedly over the past several decades; first with the introduction of targeted therapies and more recently with data supporting checkpoint inhibition. However, the vast majority of studies to date have explored the benefit of agents specifically in the context of clear cell disease. For the estimated 15-20% of patients with non-clear cell histology, there is little consensus around best practice. Herein, we discuss emerging datasets providing biologic characterization of non-clear cell RCC and identify trials that exploit this biology.

Unique Transcriptomic Profile of Collecting Duct Carcinomas Relative to Upper Tract Urothelial Carcinomas and other Kidney Carcinomas

Collecting duct carcinoma (CDC) is a kidney cancer subtype that is thought to arise from principal cells in distal parts of the collecting ducts. Some studies suggested an overlap of CDC with upper tract urothelial carcinoma (UTUC), making the pathological diagnosis challenging. Herein, we performed for the first time transcriptome sequencing of CDC and compared them to UTUC and renal cell carcinoma subtypes. We discovered that CDC displays a unique transcriptomic signature among kidney cancer subtypes, with a putative cell of origin in the distal convoluted tubules. Hierarchical unsupervised clustering reveals that the CDC signature is closer to that of other RCC subtypes than to UTUC, which is similar to that of bladder carcinoma. CDC is characterized by a metabolic shift, with impairment of oxidoreductase activity, pyruvate metabolism and the tricarboxlyic acid cycle, as well as an immunogenic response consistent with increased tumor infiltrating lymphocytes, particularly within metastatic cases. In addition, pathways differentially altered between CDC and UTUC point to a basal-like phenotype of CDC in contrast to the luminal-like signature of UTUC. We conclude that CDC harbors a pathognomonic transcriptomic signature characterized by immunogenic and a metabolic aberrations, indicating that targeting these processes might provide therapeutic options for patients.

Clinical and computed tomography imaging features of renal medullary carcinoma: A report of six cases

Patients with renal medullary carcinoma (RMC) have a poor prognosis, usually due to late diagnosis. Computed tomography (CT) analysis may aid the differentiation between RMC and other types of renal cell carcinoma, in order to establish an accurate early diagnosis. There is a limited number of reports in the literature focusing on clinical and multi-slice CT (MSCT) imaging findings of RMC. Consequently, the present study aimed to characterize the clinical and MSCT imaging features of RMC. For this purpose, the MSCT imaging findings of 6 patients with RMC were retrospectively studied. The patients were subjected to MSCT in order to investigate the characteristics of the tumors, including location, size, density, calcification, cystic or solid appearance, capsule sign, enhancement pattern and presence of retroperitoneal lymph node metastasis. The tumors in the current study presented a mean diameter of 7.48±3.25 cm, and were observed to be solitary and heterogeneous with necrotic components. The majority of the tumors did not contain calcifications (5/6); displayed an ill-defined margin (4/6); were centered in the medulla; extended into the renal pelvis or peripelvic tissues (6/6); and did not exhibit a fibrous capsule. Localized caliectasis was observed in 3 of the 6 cases. The attenuation of the solid region of the RMC on unenhanced CT was equal to that of the renal cortex or medulla (42.3±2.7 vs. 40.7±3.6 and 41.2±3.9 Hounsfield units, respectively; P>0.05) while, on enhanced CT, the enhancement of the tumor was lower than that of the normal renal cortex and medulla during all phases (cortical phase, 52.6±4.8 vs. l99.5±9.7 and 72.7±6.4; medullary phase, 58.6±5.7 vs. 184.6±10.8 and 93.5±7.8; delayed phase, 56.8±6.1 vs. 175.7±8.5 and 96.5±7.9, respectively; P<0.05). In conclusion, RMC tends to be an infiltrative, ill-defined heterogeneous mass with intratumoral necrosis, which arises from the renal medulla, and displays lower enhancement than the renal cortex and medulla during all phases on enhanced CT. Despite its rarity in adults, RMC should be included in a differential diagnosis when CT imaging reveals these features.

Collecting Duct Renal Cell Carcinoma Found to Involve the Collecting System During Partial Nephrectomy: A Case Report

Collecting duct carcinoma (CDC) is a rare and aggressive form of renal cell carcinoma (RCC) arising from the principal cells of the collecting duct. One third of cases present with metastatic disease, but many present in a manner similar to conventional RCC or urothelial carcinoma (UC). We discuss a case of CDC which presented as a small mass at the cortico-medullary junction, and was discovered at robotic partial nephrectomy (RPN) to be grossly involving the collecting system. A 62-year-old man presented with a small renal mass suspicious for RCC, which was found on computed tomography (CT) after an episode of gross hematuria. After thorough workup, RPN was attempted; however, intraoperatively the mass was found to be involving the collecting system. Radical nephroureterectomy was performed, and the pathology report revealed CDC. CDC is a rare and aggressive form of RCC. While many cases are metastatic at diagnosis, most patients present with the incidental finding of a small renal mass. There are no reports of a CDC involving the collecting system at RPN after negative ureteroscopy preoperatively. The adjuvant therapeutic options for CDC are limited, and long term survival is poor.