Clear cell and non-clear cell renal cell carcinoma in young adults: clinicopathological features, survival outcomes and prognostic factors.

OBJECTIVES: Renal cell carcinoma (RCC) is infrequent among young adults. Few studies reported the outcome of RCC in young adults by pathological subtypes. The purpose of this study was to explore the clinicopathological features, survival outcomes and prognostic factors of young adult patients with clear cell (CCRCC) and non-clear cell renal cell carcinoma (NCCRCC). METHODS: This study included young adult patients aged 18-40 years who were diagnosed as renal cell carcinoma (RCC) between 2012 and 2022 at Peking University Third Hospital. All patients underwent either partial nephrectomy or radical nephrectomy, and some received adjuvant therapy. A comparative analysis was performed to investigate the differences in clinicopathological characteristics between the cohort of CCRCC and NCCRCC. Kaplan-Meier survival analysis was utilized to plot survival curves for young adults with RCC. The univariate and multifactorial prognostic analyses were conducted using the log-rank test and COX proportional hazards model. RESULTS: A total of 300 RCC patients aged 18-40 years were performed, of which 201 were diagnosed with CCRCC (67%) and 99 were diagnosed with NCCRCC(33%). The NCCRCC included 29 cases (9.7%) of chromophobe RCC, 28 cases (9.3%) of MiT family translocation RCC, 22 cases (7.3%) of papillary RCC, 11 cases (3.7%) of low malignant potential multifocal cystic RCC, and 6 cases of unclassified RCC (2.0%), 2 cases of mucinous tubule and spindle cell carcinoma (0.7%), and 1 case of FH-deficient RCC (0.3%).The mean age was 33.4 ± 6.1 years old. The overall and progression free 5-year survival rate was 99.1 and 95.3%, respectively. The NCCRCC cohort demonstrated a statistically significant decrease in progression-free survival (PFS) rate when compared to the CCRCC cohort (p < 0.001). There was no statistically significant difference observed in overall survival (OS) (p = 0.069). Pathological stage was a significant independent predictor for OS (p = 0.045). Pathological stage and nuclear grade were both independent predictors for PFS (p = 0.020; p = 0.005). CONCLUSIONS: The clinical and pathological features of young adults diagnosed with CCRCC exhibit notable distinctions from those of NCCRCC patients. The survival outcome was significantly influenced by the pathological stage, while both the nuclear grade and pathological stage had a significant impact on tumor progression. This study offered significant contributions to the understanding of the clinicopathological characteristics and prognostic determinants of renal cell carcinoma (RCC) in young adults.

Targeted therapies and the treatment of non-clear cell renal cell carcinoma.

BACKGROUND: Targeted therapies have shown profound effects on the outcome of patients with advanced renal cell carcinoma (RCC). However, the optimal treatment for RCC of non-clear cell histology (nccRCC)-typically excluded from trials of targeted agents-remains uncertain. MATERIALS AND METHODS: By carrying out extensive searches of PubMed and ASCO databases, we identified and summarised research into the biological characteristics, clinical behaviour and treatment of different histological subtypes of nccRCC, focusing on targeted therapy. RESULTS: The available data suggest that treatments currently approved for RCC are active in ncc subtypes, although the overall clinical benefit may be less than for clear cell RCC. Temsirolimus has proven benefit over interferon-alfa (IFN-α) in patients with nccRCC, based on phase III data, while everolimus, sunitinib and sorafenib have all demonstrated some degree of activity in nccRCC in expanded-access trials. No clear picture has emerged of whether individual histological subtypes are particularly responsive to any individual treatment. CONCLUSIONS: Further molecular studies into the pathogenesis of RCC histological subtypes will help direct the development of novel, appropriate targeted agents. Clinical trials specifically designed to evaluate the role of targeted agents in nccRCC are ongoing, and data from trials with sunitinib and everolimus will be reported soon.

Advanced Non-Clear Cell Renal Cell Carcinoma Treatments and Survival: A Real-World Single-Centre Experience.

BACKGROUND: Non-clear cell renal cell carcinoma (nccRCC) is a heterogeneous group of cancer. Treatment recommendations are extrapolated from ccRCC and lack solid evidence. Here, we review advanced nccRCC patients treated at our institute. PATIENTS AND METHODS: We collected retrospective data on all advanced nccRCC pts treated at the Istituto Oncologico Veneto from January 2008. We compared overall response rate (ORR), progression free survival (PFS) and overall survival (OS) according to histological subtypes and type of systemic treatments. Kaplan-Meier method, log-rank test and Cox regression were used to estimate and compare PFS and OS. RESULTS: Of 1370 RCC patients, 289 had a diagnosis of nccRCC and 121 were eligible for the analysis. Fifty-three pts showed papillary histology (pRCC), 15 chromophobe; 37 unclassified RCC (NOS-RCC), 16 other histologies. Pts with chromophobe and other hystologies showed poorer survival rates compared to pRCC and NOS-RCC (mOS 10.7 vs. 20.7 vs. 30.7, p = 0.34). Pts treated with combination regimens achieved a better OS (30.7 vs. 13.7, p = 0.10), PFS (12.7 vs. 6.4, p = 0.10) and ORR (42.4% vs. 13.9%, p = 0.002) than those treated with monotherapy. IMDC and Meet-URO score retained their prognostic value. CONCLUSION: Our retrospective real-life cohort of advanced nccRCC patients shows that immunotherapy-based combinations could improve ORR, PFS and OS compared to TKI monotherapy. Prospective trials for nccRCC patients utilizing novel therapies are ongoing and their results eagerly awaited.

Surgical and oncological management of renal medullary carcinoma in a young patient: a case report.

Renal medullary carcinoma (RMC) is a rare form of renal cell carcinoma that has a poor prognosis. It is known to be associated with sickle cell trait or disease, although the exact underlying mechanisms are still unclear. The diagnosis is made through immunochemical staining for SMARCB1 (INI1). In this report, we present a case of a 31-year-old male patient with sickle cell trait who was diagnosed with stage III right RMC. Despite the poor prognosis, the patient survived for a remarkable duration of 37 months. Radiological assessment and follow-up were primarily performed using 18F-FDG PET/MRI. The patient underwent upfront cisplatin-based cytotoxic chemotherapy before surgical removal of the right kidney and retroperitoneal lymph node dissection. Identical adjuvant chemotherapy was administered post-surgery. Disease relapses were detected in the retroperitoneal lymph nodes; these were managed with chemotherapy and surgical rechallenges. We also discuss the oncological and surgical management of RMC, which currently relies on perioperative cytotoxic chemotherapy strategies, as there are no known alternative therapies that have been shown to be superior to date.

Real World Data of Diagnosis, Survival, and Treatment Outcomes in Patients With Metastatic Non Clear Cell Renal Cell Carcinoma.

INTRODUCTION: Metastatic non clear cell renal cell carcinoma (nccRCC) is an heterogenous group, usually excluded from phase 3 trials. We report real life data of prognosis and systemic management of those patients. METHODS: We retrospectively included 102 metastatic nccRCC patients (unspecified papillary, n = 10; type 1 and 2 papillary n = 10 and n = 32; translocation RCC, n = 9; chromophobe, n = 14; collecting duct, n = 14) treated between 2006 and 2020. Objective response rate (ORR), progression-free survival (PFS) and overall survival (OS) were evaluated. RESULTS: Among patients who underwent pathological review, 40.8% presented a complete histological discordance. First line treatments were mainly tyrosine kinase inhibitor (60.8%), combination including immunotherapy (7.8%) or combination of chemotherapy (13.7%). Median ORR ranged from 0% in unspecified papillary RCC to 42.9% in type 1 papillary RCC. Median PFS ranged from 2.9 months in collecting duct carcinoma to 10.9 months in type 1 papillary RCC. Median OS ranged from 6.8 months in collecting duct carcinoma to 29.1 months in MiT family translocation RCC. Thirty (29.4%) patients were included in a treatment trial during their treatment course. CONCLUSION: Metastatic nccRCC patients have variable prognosis due to heterogeneity of histological subtypes. Their diagnosis and access to therapeutic innovation remain suboptimal. Dedicated prospective trials are needed.

Outcomes of patients with advanced non-clear cell renal cell carcinoma treated with first-line immune checkpoint inhibitor therapy.

BACKGROUND: Immune checkpoint inhibitors (ICI) have demonstrated impressive activity in metastatic clear-cell renal cell carcinoma (ccRCC) and have become standard treatment options for patients with advanced disease. Data supporting the effectiveness of ICI-based therapy in advanced non-clear cell RCC (nccRCC) is more limited. METHODS: We performed a retrospective analysis using the International Metastatic RCC Database Consortium (IMDC) to evaluate the outcomes of patients with advanced nccRCC. Patients were classified into three groups based on first-line therapy: ICI-based therapy (monotherapy or combination), vascular endothelial growth factor (VEGF) inhibitor monotherapy, or mammalian target of rapamycin (mTOR) inhibitor monotherapy. The primary outcome was overall survival (OS). Secondary outcomes were time to treatment failure (TTF) and objective response rate (ORR). We used the Kaplan-Meier method to compare OS and TTF between treatment groups and Cox proportional hazards models to adjust for prognostic covariates. RESULTS: We identified a total of 1145 patients with metastatic nccRCC. The most common subtype was papillary RCC (54.9%). For first-line therapy, 74.3% received VEGF monotherapy, 15% received mTOR monotherapy, and 10.7% received ICI-based therapy. Median OS in the ICI group was 28.6 months, versus 16.4 months in the VEGF group and 12.2 months in the mTOR group. Median TTF in the ICI group was 6.9 months, versus 5.0 months in the VEGF group and 3.9 months in the mTOR group. ORR was 27.2% in the ICI group, 14.5% in the VEGF group, and 9% in the mTOR group. After adjusting for the IMDC risk group, histological subtype, and age, the hazard ratio for OS was 0.57 (95% CI 0.42-0.78, p < 0.0001) for ICI versus VEGF and 0.50 (95% CI 0.36-0.71, p < 0.0001) for ICI versus mTOR. CONCLUSIONS: In advanced nccRCC, first-line ICI-based treatment appears to be associated with improved OS compared to VEGF and mTOR targeted therapy. These results should be confirmed in prospective randomised trials.

Characteristics and Treatment Challenges of Non-Clear Cell Renal Cell Carcinoma.

Non-clear cell renal cell carcinomas (RCC) comprise several rare and poorly described diseases, often characterized by bad prognosis and with no standard treatments available. The gap in their clinical management is linked to the poor molecular characterization in handling the treatment of non clear-cell RCC with untailored therapies. Due to their rarity, non-clear RCC are in fact under-represented in prospective randomized trials. Thus, treatment choices are based on extrapolating results from clear cell RCC trials, retrospective data, or case reports. Over the last two decades, various options have been considered as the mainstay for the treatment of metastatic RCC (mRCC), including angiogenesis inhibitors, vascular endothelial growth factor receptor inhibitors, other tyrosine kinase inhibitors (TKIs), as well as MET inhibitors and mammalian targeting of rapamycin (mTOR) inhibitors. More recently, the therapeutic armamentarium has been enriched with immunotherapy, alone or in combination with targeted agents that have been shown to significantly improve outcomes of mRCC patients, if compared to TKI single-agent. It has been widely proven that non-clear cell RCC is a morphologically and clinically distinct entity from its clear cell counterpart but more knowledge about its biology is certainly needed. Histology-specific collaborative trials are in fact now emerging to investigate different treatments for non-clear cell RCC. This review summarizes pathogenetic mechanisms of non-clear cell RCC, the evolution of treatment paradigms over the last few decades, with a focus on immunotherapy-based trials, and future potential treatment options.

Response to systemic therapy in fumarate hydratase-deficient renal cell carcinoma.

PURPOSE: Fumarate hydratase-deficient (FHdef) renal cell carcinoma (RCC) is a rare entity associated with the hereditary leiomyomatosis and RCC syndrome with no standard therapy approved. The aim of this retrospective study was to evaluate the efficacy of different systemic treatments in this population. METHODS: We performed a multicentre retrospective analysis of Fhdef RCC patients to determine the response to systemic treatments. The endpoints were objective response rate (ORR), time-to-treatment failure (TTF), and overall survival (OS). The two latter were estimated using the Kaplan-Meier method. RESULTS: Twenty-four Fhdef RCC patients were identified, and 21 under systemic therapy were included in the analysis: ten received cabozantinib, 14 received sunitinib, nine received "other antiangiogenics" (sorafenib, pazopanib, and axitinib), three received erlotinib-bevacizumab (E-B), three received mTOR inhibitors, and 11 received immune checkpoint blockers (ICBs). ORR for treatments were 50% for cabozantinib, 43% for sunitinib, 63% for "other antiangiogenics," and 30% for E-B, whereas ORR was 0% for mTOR inhibitors and 18% for ICBs. The median TTF (mTTF) was significantly higher with antiangiogenics (11.6 months) than with mTOR inhibitors (4.4 months) or ICBs (2.7 months). In the first-line setting, antiangiogenics presented a higher ORR compared with nivolumab-ipilimumab (64% versus 25%) and a significantly superior mTTF (11.0 months vs 2.5 months; p = 0.0027). The median OS from the start of the first systemic treatment was 44.0 months (95% confidence interval: 13.0-95.0). CONCLUSIONS: We report the first European retrospective study of Fhdef RCC patients treated with systemic therapy with a remarkably long median OS of 44.0 months. Our results suggest that antiangiogenics may be superior to ICB/mTOR inhibitors in this population.

Predictors of Progression-Free Survival and Overall Survival in Metastatic Non-Clear Cell Renal Cell Carcinoma: A Single-Center Experience.

BACKGROUND: Due to the infrequency of non-clear cell renal cell carcinoma (RCC), there is currently a paucity of high-quality literature to help guide the effective treatment of these tumors. Recently, biomarkers such as platelet to lymphocyte ratio (PLR), lymphocyte to monocyte ratio (LMR), systemic immune inflammation (SII) index and C-reactive protein to albumin ratio (CAR) have been demonstrated to be closely related to poor prognosis of patients with RCC. The objective of this study was to evaluate these biomarkers for determining the progression-free survival (PFS) and overall survival (OS) in patients with metastatic non-clear cell cancer. METHODS: We retrospectively reviewed 31 cases diagnosed with metastatic non-clear cell RCC from January 2012 to December 2017. We assessed the prognostic value (OS and PFS) of pretreatment PLR, LMR, SII index and CAR based on multivariate analysis and Kaplan-Meier survival curve. RESULTS: Median time of OS and PFS were 15.5 months (95% confidence interval (CI): 13.7 - 15.2) and 10.9 months (95% CI: 8.9 - 12.8), respectively. The median PFS (0.001) and OS (P = 0.01) was shorter in patients with PLR > 171, LMR < 2.61. Moreover, median PFS but not OS was significantly lower in SII index > 883 (P = 0.064) and CAR > 0.11 (P = 0.229). Scan to surgery time (3.91 weeks, P = 0.001) was also significantly related to progression. CONCLUSIONS: Elevated pretreatment inflammatory biomarkers such as PLR, LMR, SII index and CAR are significant determinants of shorter PFS and OS (PLR and LMR only) in patients with metastatic non-clear cell RCC treated with cytoreductive nephrectomy.

Investigational MET inhibitors to treat Renal cell carcinoma.

Introduction: Renal cell carcinoma (RCC) consists of distinct clinical and biologic entities, with an urgent need for novel therapies targeting histology-specific molecular drivers of cancer growth. The MET pathway is now being targeted by multiple novel agents in clinical development. This review highlights the upcoming role of MET inhibition in the treatment of RCC. Areas covered: The HGF-MET axis is now recognized as playing a vital role in the growth of papillary histology and in driving VEGF inhibitor resistance. The heterogeneity of MET alterations influences sensitivity to MET inhibition and we need predictive biomarkers for improving patient selection. In this review, we highlight the role of the MET pathway in both clear cell and non-clear cell RCC and  provide a comprehensive review of preclinical and early clinical data on multiple drugs targeting the MET pathway. Expert opinion: MET alterations can act as primary or secondary drivers of tumor growth in RCC and represents a viable therapeutic target. Combination strategies of VEGF and MET inhibitors could lead to sustained and deep responses even in non-MET driven RCC by inhibiting pathways of VEGF resistance. Addition of checkpoint inhibitors to MET inhibition has also demonstrated promising signs of early efficacy.

Metastatic chromophobe renal cell carcinoma treated with targeted therapies: A Renal Cross Channel Group study.

BACKGROUND: Treatment of non-clear cell renal cell carcinoma (RCC) remains controversial despite several recent prospective studies of targeted therapies (TT). Often Vascular Endothelial growth Factor (VEGF) and Mammalian Target of Rapamycin (mTOR) inhibitors are used, extrapolating the data from use of these agents in clear cell RCC. METHODS: We performed a retrospective data analysis within the Renal Cross Channel Group to determine metastatic chromophobe RCC (mChRCC) outcomes in the TT era. The end-points were overall response, overall survival (OS) and time to treatment failure (TTF). The two latter were estimated using the Kaplan-Meier method. RESULTS: 91 mChRCC patients from 26 centres were included. Median follow-up from the date of first metastasis was 6.1 years (range: 0-13.9). Median OS was 37.9 months (95% confidence interval [CI]: 21.4-46.8) from the diagnosis of metastatic disease. Among the 61 patients who received TT, 50 (82%) were treated with anti-angiogenic (AA) and 11 with mTOR inhibitors. Median TTF and OS in patients receiving a first line of AA was 8.7 months (95% CI: 5.2-10.9) and 22.9 months (95% CI: 17.8-49.2) versus 1.9 months (95% CI: 1.0-6.0) and 3.2 months (95% CI: 2.3-not evaluable) with mTOR inhibitors, respectively. A stratified log-rank test was used to compare AA and mTOR inhibitors TT, while controlling the effect of the International Metastatic RCC Database Consortium risk group and no significant difference between AA and mTOR inhibitors was observed for TTF (p = 0.26) or for OS (p = 0.55). CONCLUSION: We report the largest retrospective cohort of patients with mChRCC treated with TT and no significant difference between AA and mTOR inhibitors was observed for TTF and OS.

Addressing the best treatment for non-clear cell renal cell carcinoma: A meta-analysis of randomised clinical trials comparing VEGFR-TKis versus mTORi-targeted therapies.

AIM: Non-clear cell renal cell carcinoma (nccRCC) tumours include a heterogeneous group of malignancies that profoundly differ in terms of morphology, genetic profile, clinical behaviour and prognosis. The optimal treatment algorithm for nccRCC is still unknown and derived mainly from evidence available for ccRCC, being therefore represented by targeted agents against vascular endothelial growth factor and mammalian target of rapamycin (mTOR) pathways. We aimed to compare the efficacy of vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKis) and mTOR inhibitors (mTORi) for the treatment of nccRCC patients. METHODS: Searching the MEDLINE/PubMed, Cochrane Library and American Society of Clinical Oncology Meeting abstracts prospective studies were identified. Data extraction was conduced according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The measured outcomes were progression-free survival (PFS), overall survival (OS) and the overall response rate (ORR). RESULTS: Four randomised controlled trials were selected for final analysis, with a total of 332 patients evaluable for PFS. Treatment with TKi significantly reduced the risk of progression compared with mTORi (hazard ratio [HR] = 0.71; 95% confidence interval [CI] 0.60-0.84; p < 0.0001). This difference remained significant when sunitinib was compared with everolimus in first-line setting (HR = 0.67; 95% CI, 0.56-0.80; p < 0.00001). In the 332 patients evaluable for OS, no significant difference was found between TKi and mTORi (HR = 0.86; 95% CI, 0.67-1.12; p = 0.27). In the 176 evaluable patients, TKis therapy did not improve the ORR when compared with mTORi (relative risk [RR] = 2.21; 95% CI, 0.87-5.60; p = 0.09), even if treatment with sunitinib doubled the probability of achieving a tumour response. CONCLUSIONS: Treatment with TKis significantly improves PFS, but not OS, when compared with mTORi. Moreover, sunitinib as first-line therapy reduces the risk of progression compared with everolimus; therefore, supporting the standard treatment paradigm broadly used for ccRCC patients. The relatively modest efficacy of available targeted therapies reinforces the need of future histology based, molecular driven therapeutic paradigm.

Open-label phase 2 trial of first-line everolimus monotherapy in patients with papillary metastatic renal cell carcinoma: RAPTOR final analysis.

BACKGROUND: Papillary histology accounts for 10-15% of renal cell carcinoma (RCC), and treatment options for patients with this subtype are limited. The RAPTOR (RAD001 in Advanced Papillary Tumor Program in Europe; ClinicalTrials.gov, NCT00688753) study evaluated first-line everolimus in patients with papillary metastatic RCC (mRCC). METHODS: This phase 2 trial enrolled previously untreated patients with type 1 or type 2 papillary mRCC. Papillary histology was confirmed by central review and was performed for every patient. Patients received oral everolimus 10 mg once daily until disease progression or unacceptable toxicity. The primary end-point was progression-free survival (PFS) rate at 6 months among the first 44 patients of the per protocol (PP) population. Secondary end-points included PFS, tumour response, overall survival (OS), and safety. FINDINGS: Analysis sets included safety (N = 92; 100%), intent-to-treat (ITT) (n = 88), and PP populations (n = 46). In the safety population, most patients were men (78%) and the mean age was 60 years (range 23-84). Papillary histology was confirmed in 78% of patients (type 1, 32%; type 2, 64%; missing information, 4%). PFS rate at 6 months was 34% (80% confidence interval [CI] 25-45). In the ITT population, median PFS was 4.1 months (95% CI 3.6-5.5), 65% of patients achieved stable disease, and median OS was 21.4 months (95% CI 15.4-28.4). Among patients with type 1 or type 2 histology, median PFS was 7.9 months (95% CI 2.1-11.0) and 5.1 months (95% CI 3.3-5.5), respectively, and median OS was 28.0 months (95% CI 7.6-not estimable) and 24.2 months (95% CI 15.8-32.8), respectively. Common grade >2 adverse events were asthenia (13%), anaemia (7%), and fatigue (5%). INTERPRETATION: Results of this large prospective study in papillary mRCC demonstrated that everolimus provides some clinical benefit to this patient population and highlight the need for central pathological review of this rare tumour.