Primary Renal Tumors Research Articles

Survival rate comparisons of angioembolization and neoadjuvant targeted therapy on unresectable renal cell carcinoma patients: A systematic review

Objective: Renal cell cancer (RCC) is the most typical form of kidney cancer in adults, which accounts for 80% to 85% of all primary renal neoplasms. RCC develops inside the renal cortex. This study aimed to systematically review the survival rate of patients treated with targeted therapy and/or RC. Surgery is the standard therapy for RCC, even though after surgery, 20%–40% of patients with localized RCC would experience distant metastases. Metastases or large RCC are not amenable to surgery. Unresectable RCC can be treated palliatively with angioembolization or neoadjuvant therapy. This study aims to review the survival rate comparisons of angioembolization and neoadjuvant targeted therapy on unresectable renal cell carcinoma. Methods: A thorough search across databases such as PubMed, Cochrane Library, and ProQuest was conducted for articles published from 2018 to 2023. To uphold research integrity, duplicates, reviews, and incomplete articles were excluded, ensuring only pertinent and original research findings for subsequent analysis. Results: Database search yielded 247 articles, which were systematically eliminated, leaving 6 relevant articles. Analyzed articles showed the overall survival of patients treated with angioembolization and neoadjuvant agents. Conclusion: Unresectable RCC can be treated palliatively with angioembolization. Angioembolization may improve clinical effectiveness and lessen side effects by boosting local concentrations of drugs. Drug-eluting bead transarterial chemoembolization is a novel embolization option that can embolize the arteries that feed the tumor and cutoff the blood supply to the tumor. Sunitinib, the most studied medicinal agent, was found to have higher effectiveness when combined with angioembolization.

TFE3-rearranged nonmelanotic renal PEComa: a case series expanding their phenotypic and fusion landscape.

A subset of exceptionally rare primary renal perivascular epithelioid cell tumours (PEComas) that harbour Xp11.2 translocation have been reported, but no larger series devoted to this topic have been published. We describe the clinicopathological and molecular features of 10 renal PEComas, collected from our routine and consultation files. There were five female and five male patients aged 14-65 (median: 32 years). One patient had a history of childhood neuroblastoma, but no patients were known to have a tuberous sclerosis complex or other hereditary disorder. Complete surgical excision was the treatment for all patients. The available follow-up in five patients indicated a favourable outcome in 4/5 cases. Tumour size ranged from 2.8 to 15.2 cm (median, 5.2 cm). Immunohistochemistry revealed consistently strong TFE3 expression in all tumours, whereas PAX8 and keratin cocktails were uniformly negative. Other positive markers included HMB45 (7/9 tumours), CathepsinK (7/9 tumours), and CD117 (KIT) (3/5 tumours). TFE3 rearrangements were detected in 8/9 tumours (by targeted RNA sequencing in seven and by FISH in one). The identified fusion partners included SFPQ (n = 2) and one tumour each with ASPSCR1, ZC3H4, MED15, RBMX, and PRCC. One tumour that lacked TFE3 rearrangement by next-generation sequencing (NGS) and fluorescence in situ hybridization (FISH) revealed a large intrachromosomal deletion involving PKD1 and TSC2 by DNA-based NGS. This study highlights the morphologic and genetic diversity of TFE3-rearranged primary renal PEComas and underlines the value of surrogate TFE3 immunohistochemistry in identifying them. The lack of PAX8 and keratin expression represents the mainstay for distinguishing these tumours from MiTF-associated renal cell carcinomas. In addition, we report rare (ZC3H4, RBMX) and novel (MED15) TFE3 fusion partners in PEComa.

11 Tumor evolution of brain-specific tropism in metastatic renal cell carcinoma

Abstract Background Brain metastases (BMets) pose a clinical challenge in the management of patients (pts) with metastatic renal cell carcinoma (RCC), leading to significant morbidity and mortality. Herein, we sought to comprehensively characterize the molecular landscape of BMets in RCC. Methods We performed panel-based DNA (DNAseq) and whole transcriptome (RNAseq) sequencing to analyze BMets, matched non-Brain metastases (nBMets), and matched primary renal tumors (PRT) from pts who underwent surgical resection of BMet(s) from RCC at our institution. Results Our cohort consisted of 95 samples from 53 patients (BMets = 54, nBMets = 14, PRT = 27) with clear cell histology in 45 pts (84.9%). DNAseq was available on 85 samples (50 pts). Patient-level mutations revealed recurring mutations in VHL (18 pts, 36%), TP53 (n = 12 pts, 24%), PBRM1 (12 pts, 24%), SETD2 (12 pts, 24%), and BAP1 (4 pts, 8%). Mutations within the MTOR signaling pathway were enriched, with 25 pts (50%) having at least one mutation in PTEN (12 pts, 24%), TSC1 (4 pts, 8%), TSC2 (5 pts, 10%), or MTOR (9 pts, 18%). Copy number analyses revealed frequent deletions in chr14q21 (34 pts, 68%) and chr9p21 (35 pts, 70%) and gains in chr20q13 (n = 31, 62%) and chr7p15 (n = 31, 62%). At the sample-level, PTEN mutations were more common in BMets (11 pts, 22.9%) vs nBMets (0 pts) and PRTs (3 pts, 12%, p = 0.124), as were deletions in chr13q22 (BMets = 13pts [26.5%], nBMet = 1pts [8.3%], PRT = 1 [4%]; p = 0.036) and gains in chr20q13 (BMets = 30pts [61.2%], nBMet = 4pts [33.3%], PRT = 8 [32%]; p = 0.03). Deletions in chr9p21 were enriched in BMets (32, 65.3%) and nBMets (8, 66.7%) relative to PRTs (7, 28%, p = 0.006), whereas other copy number alterations and somatic mutations exhibited similar proportions across specimen sites. Differential expression analysis performed on 86 samples (51 pts) identified 806 differentially expressed genes (DEGs) between BMets and PRT (adjusted [adj.] p < 0.05) and 399 DEGs between BMet and nBMets (adj. p < 0.05). Gene set enrichment analysis of MSigDB Hallmark gene sets revealed upregulation of MTORC1 signaling, glycolysis, and MYC targets in BMets comparted to PRT and nBMETs (adj. p <0.0001). In contrast, immune-related gene sets, such as interferon-alpha, interferon-gamma, and tumor necrosis factor-alpha, were enriched in PRT relative to BMets (adj. p <0.0001), but not nBMETs (adj. p > 0.05). CIBERSORT cellular deconvolution analysis comparing BMets with PRT revealed decreased proportions of M1 macrophages (p = 0.0003) and CD8+ T-cells (p = 0.0106), but an increased proportion of M2 macrophages (p = 0.0009). Conclusions RCC with brain metastases are characterized by distinct copy number alterations, enrichment of MTOR pathway mutations, MTOR pathway hyperactivation, and an immunosuppressive tumor milieu. These findings may hold therapeutic implications of MTOR pathway inhibition and immune modulators in treating RCC BMets.

Clear cell renal cancer metastasis - A case of delayed diagnosis.

Renal cell carcinoma represents about 90% of all primary renal neoplasms. Clear cell renal cell carcinoma is the most common histological type, characterized by an aggressive clinical course due to its tendency to metastasize. Metastases are typically diagnosed on average 5 years after oncological surgery. Compared to metastasis to other organs, pancreatic metastases are rare. We present a case of clear cell renal carcinoma metastasis to the pancreas and liver, diagnosed 23 years after nephrectomy during the investigation of portal hypertension findings. Evaluating the late recurrence of clear cell renal carcinoma is crucial. There are no guidelines regarding the appropriate follow-up period after nephrectomy, and prospective studies may be useful in the future.

Comparison of Primary and Metastatic Fumarate Hydratase-Deficient Renal Cell Carcinomas Documents Morphologic Divergence and Potential Diagnostic Pitfall With Peritoneal Mesothelioma

Fumarate hydratase (FH)-deficient renal cell carcinomas are rare neoplasms characterized by wide morphologic heterogeneity and pathogenetic mutations in the FH gene. They often show aggressive behavior with rapid diffusion to distant organs, so novel therapeutic scenarios have been explored, including EGFR inhibitors and PD-L1 expression for targeted immunotherapy. Herein, we investigated a series of 11 primary FH-deficient renal cell carcinomas and 7 distant metastases to evaluate tumor heterogeneity even in metastatic sites and estimate the specific spread rates to various organs. Furthermore, the tumors were tested for immunohistochemical PD-L1 expression and EGFR mutations. Most metastatic cases involved the abdominal lymph nodes (4/7; 57%), followed by the peritoneum (3/7; 42%), the liver (2/7; 29%), and the lungs (1/7; 14%). Six metastatic localizations were histologically documented, revealing a morphologic heterogeneous architecture often differing from that of the corresponding primary renal tumor. Peritoneal involvement morphologically resembled a benign reactive mesothelial process or primary peritoneal mesothelioma, thus advocating to perform an accurate immunohistochemical panel, including PAX8 and FH, to reach a proper diagnosis. A pure low-grade succinate dehydrogenase–looking primary FH-deficient renal cell carcinoma was also recorded. As for therapy, significant PD-L1 labeling was found in 60% of primary renal tumors, whereas none of them carried pathogenetic EGFR mutations. Our data show that FH-deficient renal cell carcinoma may be morphologically heterogeneous in metastases as well, which involve the lymph nodes, the liver, and the peritoneum more frequently than other renal tumors. Due to the high frequency of this latter (42%), pathologists should always be concerned about ruling out mesothelial-derived mimickers, and the occurrence of rarer, primary, low-grade–looking types. Finally, contrary to EGFR mutations, PD-L1 expression could be a possible predictive biomarker for the therapy of these tumors.

Factors Associated with Outcomes at 1 Year in Paediatric Post-nephrectomy Patients for Nephroblastoma at the University Teaching Hospital and Cancer Diseases Hospital in Lusaka, Zambia.

Nephroblastoma is the most common primary malignant renal tumour of childhood. The survival rates in high-income countries are approximately 90%. However, low-income countries have low survival rates of 20%-50%. This study assessed factors associated with treatment outcomes of children post-nephrectomy for nephroblastoma at the University Teaching Hospital and Cancer Diseases Hospital in Lusaka, Zambia. A retrospective observational cohort study was conducted, where all children diagnosed with unilateral Wilms tumour below the age of 16 years who had nephrectomy from July 2016 to June 2019 were enrolled. Sociodemographic, clinical characteristics and treatment outcomes were noted. All data were coded and stored in a tabular format using Microsoft Excel. Statistical software STATA version 13 was used for analysis. Thirty patients were enrolled. The male-to-female ratio was 1:1. The 1-year event-free survival was 46.7%. Treatment abandonment accounted for 36.6% of the participants. 16.7% of the patients had disease progression. No patient had a relapse or died during the 1-year follow-up period. 66.7% had advanced disease stages III and IV. Advancement in age (above 4.3 years), living in a rural environment more than 100 km away from Lusaka and advanced disease stage were all associated with a poor outcome. Factors associated with a poor outcome in this study were advanced age and late presentation.

Thrombectomy under deep hypothermic circulatory arrest (DHCA) for renal cell carcinoma with atrio-caval thrombus

Renal cell carcinoma accounts for 85–90 % of all primary renal neoplasms and has the propensity to expand and directly invade contiguous structures such as the inferior vena cava predisposing to thrombus formation in approximately 10 % of cases. Overall, 70 % of patients survive for 5 years. While several classifications have been published to characterize the level of thrombus involvement and subsequently define the appropriate surgical treatment, the prognosis of such remains to be ascertained. Furthermore, controversies exist as to the most appropriate surgical approach particularly for atrial thrombus (Level IV). Although traditionally such thrombus level is addressed using cardiopulmonary bypass with or without deep hypothermic arrest, there have been recent reports of a less invasive maneuver using a transdiaphragmatic approach, essentially milking the thrombus down, avoiding sternotomy. We present our initial case of a 59-year-old male having a right renal mass with extensive thrombus from the inferior vena cava up to the right atrium managed with radical nephrectomy and thrombectomy under cardiopulmonary bypass with deep hypothermic circulatory arrest. Patient remains tumor-free after 1 year of follow-up.

Remineralization of lytic spinal metastases after radiation therapy – A retrospective cohort study comparing conventional external beam radiation therapy with stereotactic ablative body radiation

IntroductionOsteolytic spinal metastases (SM) have a higher risk of fracture. In this study we aim to confirm the remineralization of lytic SM after radiation therapy. Secondary the influence of SBRT compared to cEBRT and tumor type will be analyzed. MethodsA retrospective cohort study was performed. Results87 patients, 100 SM were included. 29 received SBRT, 71 cEBRT. Most common primary tumors were breast (35 %), lung (26 %) and renal (11 %). Both cEBRT and SBRT resulted in a significant increase of bone mineral density (BMD) (83.76 HU ± 5.72 → 241.41 HU ± 22.58 (p < 0.001) and 82.45 ± 9.13 → 179.38 ± 47.83p = 0.026). There was a significant increase in absolute difference of BMD between the SM and reference vertebrae (p < 0.001). There was no significant difference between SBRT and cEBRT. There was no increase of BMD in renal lytic SM after radiation therapy (pre-treatment: 85.96 HU ± 19.07; 3 m 92.00 HU ± 21.86 (p = 0.882); 6 m 92.06 HU ± 23.94 (p = 0.902); 9 m 70.44 HU ± 7.45 (p = 0.213); 12 m 98.08 HU ± 11.24 (p = 0.740)). In all other primary tumors, a significant increase of BMD after radiation therapy was demonstrated (p < 0,05). ConclusionWe conclude that the BMD of lytic SM increases significantly after radiation therapy. Lytic SM of primary renal tumors are the exception; there is no significant remineralization of renal lytic SM after radiation therapy. There is no benefit of SBRT over cEBRT in this remineralization. These findings should be taken into account when deciding on surgery in the potentially unstable group defined by the spinal instability neoplastic score.

Tumor evolution of brain-specific tropism in metastatic renal cell carcinoma.

4530 Background: Brain metastases (BMets) pose a clinical challenge in the management of patients (pts) with metastatic renal cell carcinoma (RCC), leading to significant morbidity and mortality. Herein, we sought to comprehensively characterize the molecular landscape of BMets in RCC. Methods: We performed panel-based DNA (DNAseq) and whole transcriptome (RNAseq) sequencing to analyze BMets, matched non-Brain metastases (nBMets), and matched primary renal tumors (PRT) from pts who underwent surgical resection of BMet(s) from RCC at our institution. Results: Our cohort consisted of 95 samples from 53 patients (BMets = 54, nBMets = 14, PRT = 27) with clear cell histology in 45 pts (84.9%). DNAseq was available 85 samples (50 pts). Patient-level mutations revealed recurring mutations in VHL(18 pts, 36%), TP53 (n = 12 pts, 24%), PBRM1(12 pts, 24%), SETD2(12 pts, 24%), and BAP1(4 pts, 8%). Mutations within the MTOR signaling pathway were enriched, with 25 pts (50%) having at least one mutation in PTEN (12 pts, 24%), TSC1 (4 pts, 8%), TSC2 (5 pts, 10%), or MTOR (9 pts, 18%). Copy number analyses revealed frequent deletions in chr14q21 (34 pts, 68%) and chr9p21 (35 pts, 70%) and gains in chr20q13 (n = 31, 62%) and chr7p15 (n = 31, 62%). At the sample-level, PTEN mutations were more common in BMets (11 pts, 22.9%) vs nBMets (0 pts) and PRTs (3 pts, 12%, p = 0.124), as were deletions in chr13q22 (BMets = 13pts [26.5%], nBMet = 1pts [8.3%], PRT = 1 [4%]; p = 0.036) and gains in chr20q13 (BMets = 30pts [61.2%], nBMet = 4pts [33.3%], PRT = 8 [32%]; p = 0.03). Deletions in chr9p21 were enriched in BMets (32, 65.3%) and nBMets (8, 66.7%) relative to PRTs (7, 28%, p = 0.006), whereas other copy number alterations and somatic mutations exhibited similar proportions across specimen sites. Differential expression analysis performed on 86 samples (51 pts) identified 806 differentially expressed genes (DEGs) between BMets and PRT (adjusted [adj.] p &lt; 0.05) and 399 DEGs between BMet and nBMets (adj. p &lt; 0.05). Gene set enrichment analysis of MSigDB Hallmark gene sets revealed upregulation of MTORC1 signaling, glycolysis, and MYC targets in BMets comparted to PRT and nBMETs (adj. p &lt;0.0001). In contrast, immune-related gene sets, such as interferon-alpha, interferon-gamma, and tumor necrosis factor-alpha, were enriched in PRT relative BMets (adj. p &lt;0.0001), but not nBMETs (adj. p &gt; 0.05). CIBERSORT cellular deconvolution analysis comparing BMets with PRT revealed decreased proportions of M1 macrophages (p = 0.0003) and CD8+ T-cells (p = 0.0106), but an increase proportion of M2 macrophages (p = 0.0009). Conclusions: RCC with brain metastases are characterized by distinct copy number alterations, enrichment of MTOR pathway mutations, MTOR pathway hyperactivation, and an immunosuppressive tumor milieu. These findings may hold therapeutic implications of MTOR pathway inhibition and immune modulators in treating RCC BMets.

Molecular analysis of primary and metastatic sites in patients with renal cell carcinoma.

BACKGROUNDMetastases are the hallmark of lethal cancer, though underlying mechanisms that drive metastatic spread to specific organs remain poorly understood. Renal cell carcinoma (RCC) is known to have distinct sites of metastases, with lung, bone, liver, and lymph nodes being more common than brain, gastrointestinal tract, and endocrine glands. Previous studies have shown varying clinical behavior and prognosis associated with the site of metastatic spread; however, little is known about the molecular underpinnings that contribute to the differential outcomes observed by the site of metastasis.METHODSWe analyzed primary renal tumors and tumors derived from metastatic sites to comprehensively characterize genomic and transcriptomic features of tumor cells as well as to evaluate the tumor microenvironment at both sites.RESULTSWe included a total of 657 tumor samples (340 from the primary site [kidney] and 317 from various sites of metastasis). We show distinct genomic alterations, transcriptomic signatures, and immune and stromal tumor microenvironments across metastatic sites in a large cohort of patients with RCC.CONCLUSIONWe demonstrate significant heterogeneity among primary tumors and metastatic sites and elucidate the complex interplay between tumor cells and the extrinsic tumor microenvironment that is vital for developing effective anticancer therapies.

Detection of two synchronous histologically different renal cell carcinoma subtypes in the same kidney:a case report and review of the literature.

Renal cell carcinoma (RCC) is the dominant primary renal malignant neoplasm, encompassing a significant portion of renal tumors. The presence of synchronous yet histologically distinct ipsilateral RCCs, however, is an exceptionally uncommon phenomenon that is rather under-described in the literature regarding etiology, diagnosis, management, and later outcomes during follow-up. We aim to present the 9th case of a combination chromophobe RCC (ChRCC) and clear cell RCC (ccRCC) in literature, according to our knowledge, for a 69-year-old North African, Caucasian female patient who, after complaining of loin pain and hematuria, was found to have two right renal masses with preoperative computed tomography (CT) and underwent right radical nephrectomy. Pathological examination later revealed the two renal masses to be of different histologic subtypes. The coexistence of dissimilar RCC subtypes can contribute to diverse prognostic implications. Further research should focus on enhancing the complex, yet highly crucial, preoperative detection and pathological examination to differentiate multiple renal lesions. Planning optimal operative techniques (radical or partial nephrectomy), selecting suitable adjuvant regimens, and reporting long-term follow-up outcomes of patients in whom synchronous yet different RCC subtypes were detected are of utmost importance.

Abstract 7523: An integrated analysis of radiologic and pathological responses in patients with metastatic renal cell carcinoma who presented with primary renal tumor in situ and received first-line nivolumab plus ipilimumab followed by cytoreductive nephrectomy

Abstract Background: The decision to perform cytoreductive nephrectomy (CN) and timing of CN in patients (pts) with metastatic renal cell carcinoma (mRCC) and primary who respond to immune checkpoint therapy (ICT) is a matter of debate. In CheckMate-214, nivolumab plus ipilimumab (N+I) yielded a 35% objective response rate in the primary; however, there is a paucity of pathological data from nephrectomy specimens (Nx) after treatment with N+I. We sought to investigate the radiologic and pathological responses and correlate the findings with outcomes in pts receiving 1L N+I followed by CN. Methods: We reviewed the medical records and Nx of pts with mRCC who received N+I followed by CN at our institution (2016-2021). H&amp;E slides were reviewed to determine the % of residual viable malignant cells. Pathological response was defined as tumor viability ≤20%, and pathological complete response (pCR) defined as absence of residual cancer. Radiologic response was defined as ≥30% reduction in primary size. Progression-free survival (PFS) and overall survival (OS) were determined from date of CN. Results: 22 pts (median age 59) are included: 18 (81.8%) males, 19 (86%) Caucasian, 20 (91%) had clear-cell histology, 20 (91%) had ECOG Performance Status 0-1, 10 (45%) had intermediate-risk disease and 12 (55%) had poor-risk disease by IMDC. Median ICT duration before CN was 6.5 months (mo) (range, 2-19 mo). 17 (77%) completed 4 cycles of N+I, and 16 (73%) received N maintenance before CN. 5 pts (23%) had grade 3/4 immune-related adverse effects; 1 pt did not complete 4 cycles of N+I due to hepatitis. There were no therapy-related deaths. 12 pts (54.5%) had progressive disease (PD); 3 pts (14%) died of RCC. Median PFS was 22 mo, median OS not reached (NR). Pts with pathological response had greater radiologic reduction in primary size compared to pts without pathological response (median reduction 38% vs. 15% p-value 0.01), smaller final primary pathological size (median 5.7 cm vs. 10.65 cm p-value 0.002), and lower pathological yT stage (pT0: 1, pT1: 6, pT2: 2 pT3: 3, pT4: 0 vs. pT0: 0, pT1: 1, pT2: 0, pT3: 8, pT4: 1 p-value 0.045); ICT duration was similar between groups (median 5.5 mo vs. 7 mo p-value 0.733). 6 pts achieved low viability within 5 mo of ICT. In 9 pts with optimal radiopathological response [viability ≤20% and ≥30% primary size reduction], PFS was longer compared to PFS in pts with suboptimal radiopathological response: median PFS NR vs. 17 months (HR 0.23, 95% CI 0.076 - 0.741; p-value 0.041). In 13 pts with suboptimal response, 10 (77%) had PD, the most common sites of PD were lymph nodes [6 pts (60%)] and brain [3 pts (30%)]. Conclusions: In this small cohort, N+I yielded a low pCR in Nx of pts with mRCC. Radiologic response but not ICT duration was associated with low tumor viability. Citation Format: Leticia Campos Clemente, Omar Alhalabi, Matthew T. Campbell, Guillermo Corredor Alonso, Kieko Hara, Pavlos Msaouel, Andrew C. Johns, Chad Tang, Jose A. Karam, Priya Rao, Nizar M. Tannir. An integrated analysis of radiologic and pathological responses in patients with metastatic renal cell carcinoma who presented with primary renal tumor in situ and received first-line nivolumab plus ipilimumab followed by cytoreductive nephrectomy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7523.

Abstract 4555: c-Met/AXL crosstalk in mediating therapeutic resistance in renal cell carcinoma

Abstract Receptor Tyrosine Kinase (RTK), c-Met, is overexpressed in renal cancer and correlates with a decreased survival rate. Upon binding with its specific ligand, Hepatocyte Growth Factor (HGF), c-Met activates pro-tumorigenic signaling. c-Met/RTK inhibitors are used for the treatment of advanced renal cell carcinoma (RCC). However, acquired therapeutic resistance is a major clinical problem and the underlying mechanisms are largely unknown. Hence, novel therapeutic targets are needed to overcome the clinical hurdles; and the RTK, AXL, can be a potential target. AXL is overexpressed and a poor prognostic marker in RCC. AXL overexpression drives wide-ranging processes, including epithelial-to-mesenchymal transition (EMT), tumor angiogenesis, and resistance to chemotherapeutics. Cabozantinib (XL184/Cabo), is approved for advanced-stage RCC and can inhibit c-Met and VEGFR2 activation (including AXL and a few other RTKs); however, it is not a specific/potent inhibitor of AXL. Hence, inhibiting c-Met alone may not be sufficient when AXL remains active. Therefore, the pro-tumorigenic role of AXL and its cross-talk with c-Met in renal cancer need to be thoroughly investigated. We compared the expression of c-Met and AXL in TCGA and found significantly high expression of both c-Met and AXL in primary renal tumor tissues compared to normal tissues. Our data showed that AXL forms a complex with c-Met and may have a significant cross-talk which can be involved in therapeutic resistance. We have also found that prolonged treatment of c-Met inhibitor Cabo, (including Crizotinib and PF-4217903) induced c-Met and AXL overexpression in RCC cells. Interestingly, c-Met inhibitor(s)-induced overexpressed c-Met can also be increasingly phosphorylated (at low concentrations) in the presence of HGF, which may cause enhanced downstream tumor-promoting signaling. To understand the role of AXL in tumor-promoting pathways and therapeutic resistance, we have generated CRISPR/Cas9-mediated AXL knock-out cells (AXL-KO) and found that silencing AXL can prevent c-Met-inhibitor(s)-mediated c-Met overexpression. Furthermore, to identify the effect of AXL-KO on pro-tumorigenic signaling, transcriptional profiles of control clones and AXL-KO cells were compared. The gene set enrichment analysis (GSEA) showed that genes involved in ‘EMT’, ‘Hypoxia’, and ‘K-Ras’ signaling pathways were significantly downregulated. We have also utilized an AXL-specific small molecule inhibitor, TP-0903, in combination with Cabo and validated our data. We have also generated a Cabo-resistant cell line (Caki-1) and found high expression of c-Met and AXL in these cells. Furthermore, either silencing of AXL (using siRNA) or inhibiting AXL (using TP0903) induced significant apoptosis in these Cabo-resistant cells. Together, our data suggest that inhibition of AXL along with c-Met can be beneficial in preventing acquired therapeutic resistance in RCC. Citation Format: Akash Sabarwal, Laxminarayan Rawat, Johannes Wedel, Murugabaskar Balan, Gwo-Shu Mary Lee, Toni K. Choueiri, Soumitro Pal. c-Met/AXL crosstalk in mediating therapeutic resistance in renal cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4555.

Intra-Abdominal Epithelioid Neoplasm With EWSR1::CREB Fusions Involving the Kidney: A Clinicopathologic and Molecular Characterization With an Emphasis on Differential Diagnosis

Soft tissue neoplasms, harboring fusions between EWSR1 and FUS with genes encoding CREB transcription factors family (ATF1, CREB1, and CREM), are an emerging heterogeneous group of mesenchymal tumors that differ significantly in morphology, immunophenotypes, and behavior. Recently, EWSR1/FUS::CREB fusions have been recognized to define a group of aggressive neoplasms of epithelioid morphology with multiple growth patterns and a striking predilection for mesothelial-lined cavities. These neoplasms presenting as a primary neoplasm of intra-abdominal visceral organs are rare, which could elicit a wide range of differential diagnoses because of their diverse morphologies and immunohistochemical profiles. We report 3 cases of intra-abdominal epithelioid neoplasms with EWSR1::CREB fusions involving the kidney. This study included 2 female patients and 1 male patient, with age at presentation ranging from 17 to 61 years (mean: 32 years). All the patients underwent radical nephrectomy without adjunctive therapies. Grossly, the tumors were large, and all were solitary masses with sizes ranging from 5.6 to 30.0 cm (mean: 14.5 cm). Histologically, the neoplasms showed infiltrating and indistinct borders and were composed predominantly of monomorphic round-to-epithelioid cells with variable amounts of pale-to-clear cytoplasm, arranged in cords, nests, and sheets and embedded in a sclerotic hyalinized stroma with variable lymphoid cuffing either intermixed or at the periphery. Notably, a hemangiopericytomatous growth pattern was commonly seen. Nuclear atypia was mild, and mitotic activity was scarce. Immunohistochemically, all 3 cases were at least focally positive for epithelial membrane antigen and keratin AE1/AE3, with 2 tumors showing focal MUC4 expression and 1 case displaying diffuse CD34 and focal CAIX positivity. Targeted RNA sequencing identified EWSR1::CREM fusion in 2 cases and EWSR1::ATF1 fusion in 1 case. Subsequent fluorescence in situ hybridization analysis confirmed the RNA sequencing results. On follow-up, 1 patient developed multiple spinal bone metastases 5 months after the surgery while the other 2 patients were free of disease 9 and 120 months after diagnosis, respectively. Our findings demonstrate that intra-abdominal epithelioid neoplasms with EWSR1::CREB fusions may rarely occur primarily in the kidney and should be included in the differential diagnosis of primary renal epithelioid mesenchymal neoplasms.

A phase II study of neoadjuvant tislelizumab and axitinib in patients with locally advanced non-metastatic clear cell renal cell carcinoma (accRCC).

420 Background: PD-1/PD-L1 combined with vascular endothelial growth factor (VEGF) inhibitors improves survival in patients with advanced renal cell carcinoma (RCC), but the role of perioperative application in patients with localized RCC has not been established. In this phase II trial, we investigate the safety and role of tislelizumab and axitinib in downsizing tumors in patients with non-metastatic clear cell RCC prior to surgical resection. Methods: In this investigator-initiated study, 20 patients with high-risk non-metastatic ccRCC (clinical stage T2a-4 and/or N1, M0 lesions) were enrolled to receive 12 weeks of neoadjuvant ticelizumab and axitinib prior to nephrectomy. The primary endpoint was the objective response rate (complete and partial response) after neoadjuvant treatment according to RECIST v1.1. Secondary endpoints were disease-free survival (DFS), overall survival (OS), surgical outcome and safety. Results: By September 2023,13 eligible pts were enrolled. 11 pts have completed neoadjuvant therapy, with a median age of 60 (range 45-73) years, among whom 9 pts underwent surgery as planned without any delay. One patient progressed during treatment and received further systemic therapy. In 9 pts evaluable for efficacy, the investigator-assessed confirmed ORR was 55.5%. The median reduction of primary renal tumor size was 26.2% (range 12.5-45%). Pathologic results showed that one patient (11.1%) achieved a complete response (CR) by RECIST 1.1 and four patients achieved a partial response (PR). One patient who was considered unresectable became resectable at the end of treatment. Two patients were converted from radical to partial nephrectomy. The most common neoadjuvant therapy-related AEs were hematologic toxicity, hypothyroidism, nausea, vomiting, decreased appetite, fatigue, diarrhea, and elevated ALT/AST. There were no Gr4/Gr5 TRAEs. No direct intraoperative complications and no drug-related surgical complications postoperatively. Conclusions: As a neoadjuvant therapy for accRCC, the combination of tislelizumab and axitinib has clinical efficacy and a manageable safety profile. Clinical trial information: NCT05172440 .

Metastatic Renal Cell Carcinoma in a Patient With Autosomal Dominant Polycystic Kidney Disease.

Autosomal dominant polycystic kidney disease (ADPKD) manifests as multiple cysts in the kidneys and liver but can also present with musculoskeletal and cardiovascular abnormalities. ADPKD patients are at increased risk for renal cell carcinoma development. We show the FDG PET/CT findings in a patient with renal cell carcinoma secondary to ADPKD and complicated by worsening pulmonary metastasis. The primary renal tumor shows intense FDG uptake despite no suspicious features with contrast CT.

Clinicopathological Features of Primary Renal Mesenchymal Neoplasms in Adults: A Cross-sectional Study

Introduction: Renal mesenchymal tumours are a subset of primary renal tumours arising from the mesenchymal tissue in the kidney. They are a heterogeneous group of mostly benign tumours that exhibit varied behaviours and molecular characteristics. Aim: To analyse the wide spectrum of histological subtypes, their unique clinical presentation, and pathological features of primary renal mesenchymal neoplasms. Materials and Methods: This was a retrospective crosssectional observational clinicopathological study conducted in Department of General Pathology, Christian Medical College, tertiary care hospital, Vellore, Tamil Nadu, India, looking at data of adult Primary Renal Mesenchymal Tumours (PRMT) for a 15- year period between January 2006 and March 2021. Clinical details such as age, presenting symptoms, and tumour size were obtained from the hospital information system. Histopathology and immunohistochemical slides were reviewed for all the cases. Additional Immunohistochemistry (IHC) and molecular studies were performed for the undifferentiated sarcomas. The tumours were categorised into three groups as recommended by the World Health Organisation (WHO) 2020 classification of soft-tissue tumours based on biological behaviour: benign, intermediate, and malignant. Continuous variables are expressed as mean and Standard Deviation (SD). Comparison of categorical variables between groups was performed using the Chi-squared test. Continuous variables between groups were compared using the Student’s t-test for significance. A p-value of less than 0.05 was considered statistically significant. Results: Of the 2164 nephrectomies performed for neoplastic conditions, 97 (4.5%) were diagnosed as renal mesenchymal tumours. There were 59 (60.8%) benign, 10 (10.3%) with intermediate biologic behaviour and 28 (28.9%) malignant tumours. The mean ages at presentation were 40.5 years for benign, 43.4 years for intermediate, and 41 years for malignant tumours, respectively. Haematuria was seen in 11 of 38 (29%) intermediate grade and malignant tumours and in only 6 of 59 (10%) benign tumours, a difference that was statistically significant (p-value=0.017). Malignant tumours 24 of 28 (86%) were more likely to be larger (&gt;7 cm) when compared to benign tumours 28 of 59 (47%) at the time of presentation (p-value=0.027). Classical angiomyolipomas constituted 53/59 (90%) of the benign tumours. Of the 10 intermediate grade tumours, epithelioid angiomyolipomas and solitary fibrous tumours were the most common, accounting for 50% and 30% of the intermediate group, respectively. Undifferentiated small round cell sarcoma was the most common malignant neoplasm, making up 12/28 (43%) of the malignant tumours. Conclusion: The present study found that renal mesenchymal tumours constitute a small but unique group of renal tumours. They are predominantly benign, but up to a quarter are malignant. Malignant tumours tend to be larger and more often present with haematuria. The present study highlights the importance of IHC in the diagnosis of intermediate and malignant mesenchymal tumours and the requirement of exhaustive molecular studies individually tailored to the immuno-profile of malignant tumours.

Ekstrarenalni Vilmsov tumor koji je imponovao kao funikulocela

Introduction/Objective: Extrarenal Wilms' tumor (ERWT) comprises 0.5% to 1% of all nephroblastoma cases. The most common locations of ERWT are the retroperitoneum, inguinal, lumbosacral and pelvic region, female genital organs, mediastinum and chest wall, spermatic cord and paratesticular region. ERWT most likely originates from the ectopic nephrogenic rest that undergoes a malignant transformation. The exclusion of primary renal tumor is necessary to establish the diagnosis of ERWT. Patient Review: A 15-month-old male was operated on because of a left-sided inguinal mass that clinically resembled a funicular hydrocele. The surgical exploration of the inguinal canal revealed a solid tumor located in the area of the external inguinal ring, measuring around 2cm in diameter, with no ingvinal hernia present. Complete surgical resection of the mass was performed. The histological structure of the tumor corresponded to non-anaplastic nephroblastoma (Wilms tumor), mixed type. After abdominal CT scan primary renal tumor was excluded and the diagnosis of ERWT was made. Because of microscopic tumor rests on the resection margin, the patient was treated according to the high-risk SIOP Wilms tumor protocol. The patient made a full recovery. During the 10-year follow-up, the boy has remained disease-free. Conclusion: ERWT is mostly diagnosed after the surgical removal of the specimen. The clinical resemblance of the ERWT located in the inguinal region to common benign inguinal conditions in children may lead to the omission of detailed preoperative work-up. Most children with ERWT in the inguinal region have an excellent prognosis, although most of them require adjuvant chemotherapy and/or radiotherapy after surgery.

A Retrospective Cross-sectional Analysis of Renal Complications in Association with Cancer: Insights from 120 Autopsies

Introduction: Kidney diseases frequently complicate cancer and its treatment, contributing to both morbidity and mortality. Malignancies can give rise to various kidney issues, such as glomerulonephritis and Chronic Kidney Disease (CKD). This association operates bidirectionally, with patients experiencing the development of renal diseases due to cancer, and CKD predisposing to cancer. Furthermore, nephrotoxicity induced by chemotherapy can result in Acute Tubular Injury (ATI) and necrosis, imposing limitations on its application. Aim: To evaluate the spectrum of renal pathology in autopsies of malignancies. Materials and Methods: This was a retrospective crosssectional study of complete autopsies of all cases of malignancies performed in the Department of Pathology, Seth GS Medical College and KEM Hospital, Mumbai, Maharashtra, India. The study was carried out over a 5-year period from January 2015 to December 2019. Analysis of cases with respect to demographics, type of primary malignancy, gross and microscopic features, and the final cause of death was conducted. These findings were meticulously tabulated, with frequencies and percentages calculated for each category. Results: A total of 4392 autopsies were conducted throughout the study period, with 120 of them revealing the presence of malignancies. A total of 38 (31.6%) malignancies were diagnosed for the first time at autopsy. The commonest renal findings on gross were scars (superficial and deep) seen in 40 (33.33%), followed by cortical cysts in 25 (20.83%), granular contracted kidney in 15 (12.50%), mass lesions in 7 (5.83%), abscesses in 7 (5.83%), and swollen, oedematous kidneys in 6 (5%) autopsies. The most frequent renal pathology on microscopy were infective lesions seen in 43 (35.83%), Acute Tubular Necrosis (ATN) in 32 (26.66%), ATI in 30 (25%), followed by malignancies- primary and secondary in 11 (9.16%), tubular casts in 6 (5%), etc. Rare findings included membranous glomerulonephritis and Tumour Lysis Syndrome (TLS) (Acute urate nephropathy) in 1 (0.83%) each. The TLS case had classic histomorphological features of TLS, apart from laboratory parameters. Extensive deposits of uric acid crystals were seen obstructing the tubules as well as some of the glomeruli on microscopy. Conclusion: In one-third of the cases, the malignancy was exclusively discovered during the autopsy. The study revealed a diverse array of lesions, encompassing pyelonephritis, ATN, primary and metastatic renal tumours, cast nephropathy, membranous glomerulonephritis, and TLS. One-fifth of the cases had end-stage renal disease (advanced renal disease). A significant number of the cases exhibited tumour masses within the kidneys. One-fifth of the cases had renal pathology contributing to the final cause of death, further highlighting the association between malignancies and renal pathology

Pathogenesis, diagnosis and treatment of primary renal well-differentiated neuroendocrine tumors: a review of the literature.

Neuroendocrine tumors (NETs) are a rare type of neoplasm that originate from neuroendocrine cells and peptide neurons. Primary renal well-differentiated NETs are extremely rare, and only a few cases have been reported worldwide. In this study, we present a new case of primary renal well-differentiated NET at our institution, followed by a literature review. A systematic search was conducted using various search terms to identify relevant literature on primary renal well-differentiated NETs from 2021 to present. The study analyzed the clinical features, age, gender, tumor size, location, gross pathology, light microscopy, and immunohistochemical results of 32 cases of primary renal well-differentiated NETs. The findings suggest that these tumors are rare and have nonspecific clinical and imaging features. The diagnosis heavily relies on immunohistochemical analysis. Primary renal well-differentiated NETs are associated with low malignant potential and a favorable prognosis. Surgical resection is the preferred treatment, and long-term follow-up is necessary to monitor the patient's condition.