Unclassified renal cell carcinoma: diagnostic difficulties and treatment modalities

Comparative analysis of oncologic outcomes in surgically treated patients with renal cell carcinoma and renal vein thrombosis by pathologic subtypes

This study compares recurrence-free survival (RFS) and overall survival (OS) in patients with non-clear cell (nccRCC) and clear cell renal cell carcinoma (ccRCC) undergoing surgical nephrectomy with thrombectomy (SNTx) for RCC with venous thrombus. Data from patients who underwent SNTx at two tertiary centers (June 1990-December 2022) were retrospectively reviewed. Patients were grouped as ccRCC or nccRCC and stratified by metastasis status at surgery. Primary endpoints were RFS and OS for metastasis-naive RCC and OS for the entire cohort, including both metastasis-naive and metastatic RCC. Kaplan-Meier analysis with log-rank tests and adjusted multivariable Cox proportional hazards models were performed, with TN adjustments for the metastasis-naive group and TNM adjustments for the entire population. Among 604 patients, 504 (83.5%) were ccRCC. In nccRCC, 44 (44.0%) were papillary, 17 (17.0%) were chromophobe, and 39 (39.0%) were rare subtypes, most commonly TFE3 rearranged RCC, followed by the RCC not otherwise specified subtype (according to the 2022 World Health Organization Classification of RCC). Median OS was 85.8 months for ccRCC, 37.7 for papillary, 90.2 for chromophobe, and 16.9 for rare subtypes. Rare RCC histology was significantly associated with worse RFS (HR 1.63, p = 0.038) and OS (HR 1.82, p = 0.039) in metastasis-naive RCC. For the entire cohort including metastatic diseases, rare subtypes had worse OS (HR 2.20, p < 0.001), while other nccRCC subtypes did not differ significantly from ccRCC in OS. In patients with RCC with venous thrombosis, rare nccRCC subtypes exhibited poorer survival outcomes, even after adjustment for TN(M) stage.

Clinical, pathological, and oncological outcomes in unclassified renal cell carcinoma compared to clear cell renal cell carcinoma

Purpose

This study aims to assess the impact of unclassified renal cell carcinoma (uRCC) on clinical, pathological, and oncological outcomes compared with clear cell renal cell carcinoma (ccRCC).

Materials and Methods

We analyzed the data of 48 uRCC and 688 ccRCC cases, collected from a histopathological database at a single center from July 2011 to August 2019. uRCC cases were confirmed according to the 2016 World Health Organization classification. Baseline characteristics, clinical findings, and oncological outcomes were compared between the groups.

Results

Patients with uRCC exhibited the same clinical symptoms as ccRCC patients, a higher prevalence of lymphadenopathy (31.2% vs. 15.8%, P < 0.01), and greater sarcomatoid/rhabdoid differentiation on histology (12.5% vs. 5%, P = 0.03) compared to ccRCC patients. Although there was no difference regarding overall metastasis at initial diagnosis, distant lymphadenopathy (16.7% vs. 7.8%, P = 0.04) and liver metastasis (8.9% vs. 2.8%, P = 0.04) were more common in the uRCC group. The two groups had similar high-grade (HG) frequency on histology (62.5% for uRCC vs. 53.7% for ccRCC, P = 0.23). The estimated recurrence-free survival at 48 months was 94.3% for uRCC, 92.5% for low-grade (LG) ccRCC (P = 0.91), and 66.5% for HG ccRCC (P < 0.01). The estimated overall survival at 48 months was 66.1% for uRCC, 87.4% for LG ccRCC (P = 0.75), and 63.4% for HG ccRCC (P < 0.01).

Conclusion

Our study demonstrates that uRCC has significantly higher rates of lymphadenopathy, sarcomatoid differentiation, and liver metastasis compared to ccRCC. Despite these differences, uRCC presents with similar clinical symptoms and histological grade as ccRCC. Furthermore, uRCC exhibits a recurrence rate comparable to LG ccRCC and an overall survival rate similar to HG ccRCC.

Research progress of the Hippo signaling pathway in renal cell carcinoma

Objective

This review aimed to summarize the role of the Hippo signaling pathway in renal cell carcinoma (RCC), a urologic malignancy with subtle initial symptoms and high mortality rates due to metastatic RCC. The Hippo signaling pathway, which regulates tissue and organ sizes, plays a crucial role in RCC progression and metastasis. Understanding the involvement of the Hippo signaling pathway in RCC provides valuable insights for the development of targeted therapies and improved patient outcomes.

Methods

In this review, we explored the impact of the Hippo signaling pathway on RCC. Through an analysis of existing literature, we examined its role in RCC progression and metastasis. Additionally, we discussed potential therapeutic strategies targeting the Hippo pathway for inhibiting RCC cell growth and invasion. We also highlighted the importance of investigating interactions between the Hippo pathway and other signaling pathways such as Wnt, transforming growth factor-beta, and PI3K/AKT, which may uncover additional therapeutic targets.

Results

The Hippo signaling pathway has shown promise as a target for inhibiting RCC cell growth and invasion. Studies have demonstrated its dysregulation in RCC, with altered expression of key components such as yes-associated protein/transcriptional coactivator with PDZ-binding motif (YAP/TAZ). Targeting the Hippo pathway has been associated with suppressed tumor growth and metastasis in preclinical models of RCC. Furthermore, investigating crosstalk between the Hippo pathway and other signaling pathways has revealed potential synergistic effects that could be exploited for therapeutic interventions.

Conclusion

Understanding the role of the Hippo signaling pathway in RCC is of paramount importance. Elucidating its functions and molecular interactions contributes to RCC diagnosis, treatment, and the discovery of novel mechanisms. This knowledge informs the development of innovative therapeutic strategies and opens new avenues for research in RCC. Further investigations are warranted to fully comprehend the complex interplay between the Hippo pathway and other signaling pathways, ultimately leading to improved outcomes for RCC patients.

Evaluation of the clinical behavior of unclassified renal cell carcinoma and its imaging findings on computed tomography and magnetic resonance imaging based on World Health Organization (WHO) 2022

OBJECTIVES

To ascertain the clinical behaviors of unclassified renal cell carcinoma (RCC) and its characteristic imaging findings on CT and MRI.

METHODS

Subjects in this retrospective study were 10 patients who had received a histological diagnosis of unclassified RCC based on World Health Organization (WHO) 2022 and who had undergone CT and/or MRI prior to surgery. In terms of clinical behaviors, TNM classification, stage, postoperative recurrence, time to recurrence, and postoperative survival were evaluated. In terms of imaging findings, tumor size, growth pattern, CT density, dynamic contrast-enhancement (DCE) pattern, internal appearance, presence of a pseudocapsule, and signal intensity on MRI were evaluated. We compared clinical behaviors and imaging findings, and investigated associations between them.

RESULTS

One patient could not be followed-up due to death from other causes. Postoperative recurrence was observed in 4 patients, all of whom had Stage 3 RCC. In the remaining 5 patients without recurrence, all 5 patients showed Stage 2 or below. On imaging, unclassified RCC tended to be large (58.7 mm) and solid (100%), and heterogeneous interiors (80%), cystic degeneration (80%) and high intensity on diffusion-weighted imaging (DWI) (71.4%) were common. Comparing patients with and without recurrence, the following findings tended to differ between recurrence and recurrence-free groups: tumor size (73.4 ± 33.9 mm vs. 50.2 ± 33.9 mm, P = 0.286), growth pattern (invasive: 100% vs. 0%, expansive: 0% vs. 100%, P = 0.008 each), DCE pattern (progressive enhancement pattern, 66.7% vs. 0%, washout pattern, 0% vs. 66.7%, P = 0.135 each) and presence of a pseudocapsule (25% vs. 80%, P = 0.167).

CONCLUSION

The clinical behavior of unclassified RCC varies widely. Although imaging findings are also variable, findings of large, heterogeneous tumors with cystic degeneration and high intensity on DWI were common. Several imaging findings such as large size, invasive growth, progressive enhancement pattern and no pseudocapsule may enable prediction of prognosis in unclassified RCC.

Ketorolac modulates Rac-1/HIF-1α/DDX3/β-catenin signalling via a tumor suppressor prostate apoptosis response-4 (Par-4) in renal cell carcinoma

Renal cell carcinoma (RCC) is the most difficult-to-treat form of kidney cancer with a median 5-year survival of 10% under metastatic setting. In RCC, although cytoreductive nephrectomy is common, approximately 20-30% of patients will develop recurrent cancer after surgery, which highlights the need for an effective therapy. Rho-GTPases viz, Rac-1 and Cdc42 are the central regulators of cancer cell migration and invasion and thus metastasis in multiple cancer types. Hence, we elucidated the role of Ketorolac, a modulator Rho-GTPases against RCC through potentiation of tumor suppressor Par-4. The effect of Ketorolac alone and in combination on proliferation, apoptosis, cell-cycle progression, migration, tumor inhibition and their related markers were studied. Moreover, Ketorolac's impact on metastasis by influencing Rac-1/HIF-1α/DDX3/β-catenin signalling was studied with respect to its ability to modulate the expression of tumor suppressor Par-4, and this mechanism was confirmed by siRNA knockdown studies. Ketorolac induced cytotoxicity in a panel of renal cells including patient derived tumor cells with IC₅₀ 2.8 to 9.02 mM and 0.28 to 3.8 mM in monolayer and anchorage independent clonogenic assays respectively. Ketorolac caused significant down regulation of proliferation (Ki-67, Cyclin D1, pRB and DDX3), migration/invasion (Rac-1, Cdc42, and Tiam1), and angiogenesis (HIF-1α and VEGF) markers as studied by gene and protein expression. Moreover, it caused a significant upregulation of tumor suppressor Par-4 known to be downregulated in RCC. This mechanism was further confirmed by using siRNA knockdown studies where we could demonstrate a negative relation between the expression of Par-4 and Rac-1/Cdc42. Importantly, Ketorolac alone and in combination with Sunitinib showed tumor growth inhibition (TGI) of 73% and 86% respectively in xenograft model. This anti-tumor activity was further corroborated by down regulation of Rac-1/Cdc42/HIF-1α/DDX3/β-catenin signalling. This is the first report which implicates the role of Ketorolac against RCC by acting as a small molecule secretagogue causing upregulation of Par-4 in autocrine and paracrine manner. Consequently, these findings suggest that Par-4 can serve as a valuable therapeutic target and a prognostic marker for the treatment of RCC.

The role of immunotherapy in non-clear cell renal cell carcinoma

The category of non-clear cell renal cell carcinoma (nccRCC) includes several clinically, histologically, and molecularly diverse entities. Traditionally, they comprise type 1 and type 2 papillary, chromophobe, unclassified, and other histologies (medullary, collecting duct carcinoma, and translocation-associated). Molecular knowledge has allowed the identification of some other specific subtypes, such as fumarate hydratase-deficient renal cell carcinoma (RCC) or succinate dehydrogenase-associated RCC. In addition, it has recognized some alterations with a possible predictive role, e.g., MET proto-oncogene receptor tyrosine kinase (MET) alterations in papillary tumors. Standard therapies for the management of advanced clear cell RCC (ccRCC), i.e., vascular endothelial growth factor receptor (VEGFR) pathway inhibitors and mammalian target of rapamycin inhibitors, have shown poorer results in nccRCC patients. Therefore, there is a need to improve the efficacy of the treatment for advanced nccRCC. Immunotherapy, especially immune checkpoint inhibitors (ICIs) targeting programmed death 1/programmed death ligand 1 and cytotoxic T-lymphocyte associated protein 4 (CTLA-4), has demonstrated a significant survival benefit in several malignant neoplasias, including ccRCC, with a proportion of patients achieving long survival. The combinations of ICI or ICI + VEGFR tyrosine kinase inhibitors (TKIs) are the standard of care in advanced ccRCC. Unfortunately, major pivotal trials did not include specific nccRCC populations. In recent years, several studies have retrospectively or prospectively evaluated ICIs alone or in combination with another ICI or with TKIs in nccRCC patients. In this article, we review data from available trials in order to elucidate clinical and molecular profiles that could benefit from immunotherapy approaches.

Etiologies, Gross Appearance, Histopathological Patterns, Prognosis, and Best Treatments for Subtypes of Renal Carcinoma: An Educational Review

Of all primary renal neoplasms, 80-85% are renal cell carcinomas (RCCs), which develop in the renal cortex. There are more than 10 histological and molecular subtypes of the disease, the most frequent of which is clear cell RCC, which also causes most cancer-related deaths. Other renal neoplasms, including urothelial carcinoma, Wilms' tumor, and renal sarcoma, each affect a particular age group and have specific gross and histological features. Due to the genetic susceptibility of each of these malignancies, early mutation discovery is necessary for the early detection of a tumor. Furthermore, it is crucial to avoid environmental factors leading to each type. This study provides relatively detailed and essential information regarding each subtype of renal carcinoma.

Contemporary Drug Therapy for Renal Cell Carcinoma- Evidence Accumulation and Histological Implications in Treatment Strategy

Renal cell carcinoma (RCC) is a heterogeneous disease comprising a variety of histological subtypes. Approximately 70-80% of RCC cases are clear cell carcinoma (ccRCC), while the remaining subtypes constitute non-clear cell carcinoma (nccRCC). The medical treatment of RCC has greatly changed in recent years through advances in molecularly targeted therapies and immunotherapies. Most of the novel systemic therapies currently available have been approved based on ccRCC clinical trial data. nccRCC can be subdivided into more than 40 histological subtypes that have distinct clinical, histomorphological, immunohistochemical, and molecular features. These entities are listed as emerging in the 2022 World Health Organization classification. The diagnosis of nccRCC and treatments based on cancer histology and biology remain challenging due to the disease's rarity. We reviewed clinical trials focused on recent discoveries regarding clinicopathological features.

The Morphological Spectrum of Papillary Renal Cell Carcinoma and Prevalence of Provisional/Emerging Renal Tumor Entities with Papillary Growth

Renal cell carcinoma (RCC) represents a heterogeneous disease, encompassing an increasing number of tumor subtypes. Post-2016, the World Health Organization (WHO) classification recognized that the spectrum of papillary renal cell carcinoma is evolving and has long surpassed the dichotomic simplistic "type 1 versus type 2" classification. The differential diagnosis of pRCC includes several new provisional/emerging entities with papillary growth. Type 2 tumors have been cleared out of several confounding entities, now regarded as independent tumors with specific clinical and molecular backgrounds. In this work we describe the prevalence and characteristics of emerging papillary tumor entities in two renal tumor cohorts (one consisting of consecutive papillary tumors from a single institute, the other consisting of consultation cases from several centers). After a review of 154 consecutive pRCC cases, 58% remained type 1 pRCC, and 34% type 2 pRCC. Papillary renal neoplasm with reversed polarity (1.3%), biphasic hyalinizing psammomatous RCC (1.3%), and biphasic squamoid/alveolar RCC (4.5%) were rare. Among 281 consultation cases, 121 (43%) tumors had a dominant papillary growth (most frequently MiT family translocation RCCs, mucinous tubular and spindle cell carcinoma and clear cell papillary RCC). Our data confirm that the spectrum of RCCs with papillary growth represents a major diagnostical challenge, frequently requiring a second expert opinion. Papillary renal neoplasm with reversed polarity, biphasic hyalinizing psammomatous RCC, and biphasic squamoid/alveolar RCC are rarely sent out for a second opinion, but correct classification and knowledge of these variants will improve our understanding of the clinical behavior of renal tumors with papillary growth.

Diagnostic value and clinical significance of ultrasound combined with CT in cystic renal cell carcinoma

This study investigated the value and clinical significance of ultrasound combined with CT in the diagnosis of cystic renal cell carcinoma. A total of 85 patients with cystic renal cell carcinoma, who were admitted to the Oncology Department of Yantai Yuhuangding Hospital Affiliated to Qingdao University from December 2015 to April 2017, were selected as the study group, and 70 patients with benign renal cyst, who were examined in Yantai Yuhuangding Hospital Affiliated to Qingdao University, were selected as the benign group. The patients in the two groups were examined by ultrasound and CT. The diagnostic value of ultrasound, CT, and ultrasound combined with CT in cystic renal cell carcinoma was analyzed. The sensitivity of ultrasound combined with CT was significantly higher than that of CT and ultrasound (P<0.05). The specificity and diagnostic coincidence rate of ultrasound combined with CT were significantly higher than those of CT (P<0.05). For unicapsular kidney cancer, there was no significant difference among ultrasound, CT and ultrasound combined with CT in the diagnosis of septum and wall nodule (P>0.05). For polycystic kidney cancer, there was no significant difference among ultrasound, CT and ultrasound combined with CT in the diagnosis of the presence or absence of septum (P>0.05). Ultrasound was significantly better than CT in cyst wall confounding (P<0.05). Ultrasound combined with CT was significantly better than ultrasound in calcification and blood supply of tumors (P<0.05). In conclusion, the accuracy of ultrasound combined with CT is higher than that of ultrasound or that of CT in the diagnosis of cystic renal cell carcinoma, which can be beneficial in accurately carrying out clinical diagnosis, reduce the incidence of missed diagnosis and misdiagnosis caused by a single diagnosis and treatment. Ultrasound combined with CT is good for clinical screening and can guide clinical symptomatic treatment, which is worthy of generalizing in clinic.