Characterizing the outcomes of metastatic papillary renal cell carcinoma

Metastatic papillary renal cell carcinoma with portal vein tumor thrombosis confirmed on blind liver biopsy

Portal vein tumor thrombosis (PVTT) is an uncommon condition in which tumor cells expand into the vessels, causing blood clot formation in the portal vein. PVTT is mainly associated with hepatocellular carcinoma, leading to an unfavorable prognosis; however, it can also develop in patients with other cancer types. Herein, we report a case of metastatic renal cell carcinoma diagnosed by a blind liver biopsy in a patient with dynamic computed tomography-confirmed portal vein thrombosis and cholangiopathy. This case illustrates the importance of systematic surveillance with routine laboratory tests and contrast-enhanced imaging studies on patients with cancer to detect potential liver infiltration of metastatic cancer.

Locoregional Therapies in Immunologically "Cold" Tumors: Opportunities and Clinical Trial Design Considerations

Immunotherapy has revolutionized cancer management, but many tumors, particularly immunologically "cold" tumors, remain resistant to the therapy. The combination of conventional systemic immunotherapies and locoregional interventional radiology approaches is being explored to transform these cold tumors into immunologically active "hot" ones. The present article uses the example of chromophobe renal cell carcinoma (ChRCC), a renal cell carcinoma subtype resistant to current systemic immunotherapies, to address practical and conceptual challenges that have prevented the activation of clinical trials specifically designed for this malignancy to date. The practical framework discussed herein can help overcome logistic and funding limitations and facilitate the development of biology-informed clinical trials tailored to specific rare diseases such as ChRCC.

Bioinformatic analysis highlights SNHG6 as a putative prognostic biomarker for kidney renal papillary cell carcinoma

PURPOSE

Kidney renal papillary cell carcinoma (KIRP) is a highly heterogeneous malignancy and current systemic therapeutic strategies are difficult to achieve a satisfactory outcome for advanced disease. Meanwhile, there is a lack of effective biomarkers to predict the prognosis of KIRP.

METHODS

Using TCGA, GTEx, UALCAN, TIMER, TIMER 2.0 and STRING databases, we analyzed the relationship of SNHG6 with KIRP subtypes, tumor-infiltrating immune cells and potential target mRNAs. Based on TCGA data, ROC curves, Kaplan-Meier survival analysis and COX regression analysis were performed to evaluate the diagnostic and prognostic value of SNHG6 in KIRP. Nomogram was used to predict 3- and 5-year disease-specific survival in KIRP patients. In addition, with the help of Genetic ontology and Gene set enrichment analysis, the biological processes and signalling pathways that SNHG6 may be involved in KIRP were initially explored.

RESULTS

In patients with KIRP, SNHG6 was significantly upregulated and associated with a more aggressive subtype (lymph node involvement, pathological stage IV, CIMP phenotype) and poor prognosis. The ROC curve showed good diagnostic efficacy (AUC value: 0.828) and the C-index of the Nomogram for predicting DSS at 3 and 5 years was 0.920 (0.898-0.941). In the immune microenvironment of KIRP, SNHG6 expression levels were negatively correlated with macrophage abundance and positively correlated with cancer-associated fibroblasts. Furthermore, SNHG6 may promote KIRP progression by regulating the expression of molecules such as AURKB, NDC80, UBE2C, NUF2, PTTG1, CENPH, SPC25, CDCA3, CENPM, BIRC5, TROAP, EZH2. Last, GSEA suggests that SNHG6 may be involved in the regulation of the PPAR signalling pathway and the SLIT/ROBO signalling pathway.

CONCLUSIONS

Our analysis suggests that a high SNHG6 expression status in KIRP is associated with a poorer prognosis for patients, and also elucidates some potential mechanisms contributing to this poorer outcome. This may provide new insights into the treatment and management of KIRP in the foreseeable future.

Divulging a Pleiotropic Role of Succinate Receptor SUCNR1 in Renal Cell Carcinoma Microenvironment

The succinate receptor, SUCNR1, has been attributed to tumor progression, metastasis, and immune response modulation upon its activation via the oncometabolite succinate. Nonetheless, little is known about the prognostic relevance of SUCNR1 and its association with tumor immune infiltrates and microbiota in renal cell carcinoma (RCC). Herein, publicly available platforms including Human Protein Atlas, cBioPortal, TIMER2.0, and TISIDB were utilized to depict a divergent implication of SUCNR1 in the immune microenvironment of clear cell RCC (KIRC) and papillary RCC (KIRP); the two major subtypes of RCC. Our results showed that the SUCNR1 expression level was augmented in RCC compared to other solid cancers, yet with opposite survival rate predictions in RCC subtypes. Consequently, a higher expression level of SUCNR1 was associated with a good disease-specific survival rate (p = 5.797 × 10^-5) in KIRC patients albeit a poor prognostic prediction in KIRP patients (p = 1.9282 × 10^-3). Intriguingly, SUCNR1 was mainly correlated to immunomodulators and diverse immune infiltrates in KIRP. Additionally, the SUCNR1 was mostly associated with a repertoire of microbes including beneficial bacteria that likely influenced a better disease-specific survival rate in KIRC. Our findings illustrate a significant novel subtype-specific role of SUCNR1 in RCC which potentially modulates tumor immune infiltration and microbiome signature, hence altering the prognosis of cancer patients.

Advanced papillary renal cell carcinoma: Epidemiology, genomic drivers, current therapies, and ongoing trials

Papillary renal cell carcinoma (PRCC) is the most common subtype of non-clear cell renal cell carcinoma. PRCC can be subdivided into types 1 and 2 based on histology, each associated with different genetic mutations. The MET gene is commonly altered in type 1 PRCC while multiple alterations are involved in type 2 PRCC. PRCC is an aggressive cancer with a predominance in male and black patients and poor prognosis. Due to its rarity, there was a lack of convincing prospective data to guide treatment; hence, therapies were previously extrapolated from clear cell renal cell carcinoma with mixed results. More recently, some phase 2 trials focused on PRCC have been promising. Tyrosine kinase inhibitor (TKI) monotherapy is considered the standard of care, and combination strategies with TKIs and immune checkpoint inhibitors are emerging. Genetic profiling and large-scale clinical trials are needed to inform targeted treatment of PRCC.

Disparities in Cancer Specific and Overall Survival Outcomes in African Americans With Renal Cell Carcinoma: Analysis From the International Marker Consortium for Renal Cancer (INMARC)

OBJECTIVE

To investigate association of African-American race and survival in Renal Cell Carcinoma (RCC).

PATIENTS AND METHODS

We queried the International Marker Consortium for Renal Cancer database for patients who underwent partial or radical (RN) nephrectomy. The cohort was divided into African American (AA) and non-African American (NAA) patients. Primary outcome was all-cause mortality. Secondary outcome was cancer-specific mortality. Multivariable Analysis and Kaplan-Meier Analysis were used to elucidate predictive factors and survival outcomes.

RESULTS

Three thousand eight hundred and ninety-three patients were analyzed (AA, n = 564/NAA, n = 3329). AA had greater Stage I (73.8% vs 63.9%, P <.001) and papillary RCC (29.8% vs 8.5%, P <.001). Multivariable Analysis revealed increasing age (HR = 1.03, P <.001), AA (HR = 1.24, P = .027), higher stage (HR = 1.30-3.19, P <.001), RN (HR = 2.45, P <.001), clear cell (HR = 1.23, P <.001), positive margin (HR = 1.34, P .004), and high-grade (HR = 1.58, P <.001) to be associated with worsened all-cause mortality. Increasing age (HR = 1.02, P <.001), AA (HR = 1.48, P = .025), RN (HR = 2.98, P <.001), high-grade (HR = 3.11, P <.001), and higher stage (HR = 3.03-13.2, P <.001) were predictive for cancer-specific mortality. Kaplan-Meier Analysis revealed worsened 5-year overall survival for AA in stage I (80% vs 88%, P = .001), stage III (26% vs 70%, P = .001), and stage IV (23% vs 44%, P = .009). Five-year cancer-specific survival was worse for AA in stage III (36% vs 81%, P <.001) and stage IV (30% vs 49%, P = .007).

CONCLUSION

Despite presenting with more indolent histology and lower stage, African-Americans were at greater risk for diminished survival, faring worse in overall survival for all stages and cancer-specific survival in for stage III/IV RCC. Further investigation into factors associated with these disparities is warranted.

Treatment and Outcome of Metastatic Renal Cell Carcinoma With Sarcomatoid Differentiation: A Single-Center, Real-World Analysis of Retrospective Data

Background: Sarcomatoid differentiation/histology of renal cell carcinoma (sRCC) in patients with metastatic renal cell carcinoma (mRCC) is still underresearched in current therapy regimes. We aimed to evaluate the impact of sRCC on outcomes in patients with mRCC treated with tyrosine kinase inhibitors (TKIs).

Methods: We collected complete data of 262 consecutive mRCC patients from our institutional database for this retrospective study. All patients were treated with TKIs within a single or multimodal treatment approach. All analyses were adjusted for the presence of sRCC. Descriptive statistics as well as uni- and multivariable outcome metrics, including progression-free (PFS) and overall survival (OS) as endpoints were performed.

Results: Overall, 18 patients had sRCC (6.9%). Patients with sRCC had more often clear-cell histology (p = 0.047), a higher T-stage (p = 0.048), and underwent cytoreductive nephrectomy more frequently (p < 0.001). The most common first-line TKIs were Sunitinib (65.6%), Sorafenib (19.5%), and Pazopanib (10.3%), respectively. At a median follow-up of 32 months, patients with sRCC had significantly reduced PFS (p = 0.02) and OS (p = 0.01) compared to patients without sRCC. In multivariable analyses that adjusted for the effects of standard mRCC predictors, the sarcomatoid feature retained its independent association with inferior PFS (HR: 2.39; p = 0.007) and OS (HR: 2.37; p = 0.001). This association remained statistically significant in subgroup analyses of patients with Sunitinib as first-line therapy (PFS p < 0.001; OS: p < 0.001).

Conclusion: Despite its rare occurrence, our findings confirm sRCC as a powerful predictor for inferior outcomes in mRCC treated with targeted therapies. This suggests a need for more tailored treatment strategies in patients harboring mRCC with sarcomatoid histology to improve oncological outcomes.

Everolimus or sunitinib as first-line treatment of metastatic papillary renal cell carcinoma: A retrospective study of the GETUG group (Groupe d'Etude des Tumeurs Uro-Génitales)

BACKGROUND

Two phase II trials (NCT00688753 and NCT00541008) reported efficacy data of sunitinib and everolimus in first-line treatment of metastatic papillary renal cell carcinoma (mpRCC). Although most patients receive sunitinib or a mammalian target of rapamycin (mTOR) inhibitor in first- and second-line treatment, the optimal strategy remained unknown.

MATERIAL AND METHODS

In 23 centres of the Groupe d'Etude des Tumeurs Urogénitales group, after centralised pathological review, we analysed retrospectively progression-free survival (PFS) of patients with mpRCC treated in first-line treatment (PFS-1) with sunitinib or everolimus (primary end-point), PFS in second-line treatment (PFS-2), overall survival (OS), objective response rate, disease control rate (DCR), overall sequence and prognostic factors for OS (secondary end-points).

RESULTS

One hundred thirty-eight patients (119 men and 19 women), median age 62.5 years, with mpRCC type 1 (n = 24) or non-type 1 (n = 114), received first-line sunitinib (n = 107) or everolimus (n = 31). With a median follow-up of 92 months, we found no significant difference between the treatment groups in terms of PFS-1 (5.5 versus 6.2 months) and DCR (69% versus 83%). Ninety-eight patients received a second-line treatment, 69% with mTOR inhibitors after sunitinib and 100% with tyrosine kinase inhibitors after everolimus, with similar DCR (64% versus 58%), median PFS-2 (3.4 versus 4.8 months) and OS (16.0 versus 20.3 months). No factor was prognostic for PFS-1, whereas leukocytosis, anaemia and the time from diagnosis to first systemic therapy < 1 year were prognostic for OS. We found no prognostic difference between both pRCC subtypes. The International Metastatic Renal Cell Database Consortium risk factors were prognostic for OS.

CONCLUSION

Sunitinib and everolimus had similar efficacy in first-line treatment of patients with mpRCC.

The first competing risk survival nomogram in patients with papillary renal cell carcinoma

There is still a lack of competing risk analysis of patients with papillary renal cell carcinoma (pRCC) following surgery. We performed the cumulative incidence function (CIF) to estimate the absolute risks of cancer-specific mortality (CSM) and other-cause mortality (OCM) of pRCC over time, and constructed a nomogram predicting the probability of 2-, 3- and 5-year CSM based on competing risk regression. A total of 5993 pRCC patients who underwent nephrectomy between 2010 and 2016 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. The 2-, 3-, 5-year CSM rates were 3.2%, 4.4% and 6.5%, respectively, and that of OCM were 3.2%, 5.0% and 9.3%, respectively. The estimates of 5-year cumulative mortality were most pronounced among patients aged > 75 years in OCM (17.0%). On multivariable analyses, age, tumor grade, T stage, N stage, and with or without bone, liver and lung metastases were identified as independent predictors of CSM following surgery and were integrated to generate the nomogram. The nomogram achieved a satisfactory discrimination with the AUC_t of 0.730 at 5-year, and the calibration curves presented impressive agreements. Taken together, age-related OCM is a significant portion of all-cause mortality in elderly patients and our nomogram can be used for decision-making and patient counselling.

Checkpoint inhibitors in metastatic papillary renal cell carcinoma

Papillary Renal Cell Carcinoma (pRCC) is the most common non-clear cell RCC (nccRCC) and a distinct entity, although heterogenous, associated with poor outcomes. The treatment landscape of metastatic pRCC (mpRCC) relied so far on targeted therapies, mimicking previous developments in metastatic clear-cell renal cell carcinoma. However, antiangiogenics as well as mTOR inhibitors retain only limited activity in mpRCC. As development of immune checkpoint inhibitors (ICI) is now underway in patients with mpRCC, we aimed at discussing early activity data and potential for future therapeutic strategies in monotherapy or combination. Expression of immune checkpoints such as PD-L1 and infiltrative immune cells in pRCC could provide insights into their potential immunogenicity, although this is currently poorly described. Based on retrospective and prospective data, efficacy of ICI as single agent remains limited. Combinations with tyrosine-kinase inhibitors, notably with anti-MET inhibitors, harbor promising response rates and may enter the standard of care in untreated patients. Collaborative work is needed to refine the molecular and immune landscape of pRCC, and pursue efforts to set up predictive biomarker-driven clinical trials in these rare tumors.

Construction autophagy-related prognostic risk signature combined with clinicopathological validation analysis for survival prediction of kidney renal papillary cell carcinoma patients

BACKGROUND

Little data is available on prognostic biomarkers and effective treatment options for Kidney Renal Papillary Cell Carcinoma (KIRP) patients, to find potential prognostic biomarkers and new targets was an urgent mission for KIRP therapy.

METHODS

The differentially expressed autophagy-related genes (DEARGs) were screened out according to the RNA sequencing data in The Cancer Genome Atlas database, then identified survival-related DEARGs to establish a prognostic model for survival predicting of KIRP patients. Then we verified the robustness and validity of the prognostic risk model through clinicopathological data. At last, we evaluate the prognostic value of genes that formed the prognostic risk model individually.

RESULTS

We analyzed the expression of 232 autophagy-related genes (ARGs) in 289 KIRP and 32 non-tumor tissue cases, and 40 mRNAs were screened out as DEARGs. The functional and pathway enrichment analysis was done and protein-protein interaction network was constructed for all DEARGs. To sift candidate DEARGs associated with KIRP patients' survival and create an autophagy-related risk prognostic model, univariate and multivariate Cox regression analysis were did separately. Eventually 3 desirable independent prognostic DEARGs (P4HB, NRG1, and BIRC5) were picked out and used for construct the autophagy-related risk model. The accuracy of the prognostic risk model for survival prediction was assessed by Kaplan-Meier plotter, receiver-operator characteristic curve, and clinicopathological correlational analyses. The prognostic value of above 3 genes was verified individually by survival analysis and expression analysis on mRNA and protein level.

CONCLUSIONS

The autophagy-related prognostic model is accurate and applicable, it can predict OS independently for KIRP patients. Three independent prognostic DEARGs can benefit for facilitate personalized target treatment too.

Evaluation of Clear Cell, Papillary, and Chromophobe Renal Cell Carcinoma Metastasis Sites and Association With Survival

IMPORTANCE

There exists considerable biological and clinical variability between histologic variants of metastatic renal cell carcinoma (mRCC). Data reporting on patterns of metastasis in histologic variants of mRCC are sparse.

OBJECTIVE

To characterize sites of metastasis and their association with survival across the 3 most common histologic variants of mRCC: clear cell (ccRCC), papillary (pRCC), and chromophobe (chrRCC).

DESIGN, SETTING, AND PARTICIPANTS

In this multicenter, international cohort study, the International mRCC Database Consortium (IMDC) database was used to identify consecutive patients starting systemic therapy for mRCC between 2002 and 2019. Patients with mixed histologic subtype were excluded. Statistical analysis was performed from February to June 2020.

EXPOSURES

Data regarding histologic subtype and sites of metastatic involvement at the time of first systemic therapy initiation were collected.

MAIN OUTCOMES AND MEASURES

The primary outcomes were prevalence of metastatic site involvement and overall survival (OS) from time of systemic therapy initiation. Patients with multiple sites of metastatic involvement were included in analyses of all groups to which they had metastases.

RESULTS

A total of 10 105 patients were eligible for analysis. Median (interquartile range) age at diagnosis was 60 (53-67) years, 7310 (72.4%) were men and 8526 (84.5%) underwent nephrectomy. Of these, 9252 (92%) had ccRCC, 667 (7%) had pRCC, and 186 (2%) had chrRCC. The median number of sites of metastasis was 2 (range, 0-7). In ccRCC, the most common sites of metastasis were lung (70%; 6189 of 8804 patients [448 missing]), lymph nodes (45%; 3874 of 8655 patients [597 missing]), bone (32%; 2847 of 8817 patients [435 missing]), liver (18%; 1560 of 8804 [448 missing]), and adrenal gland (10%; 678 of 6673 patients [2579 missing]). Sites of metastasis varied between subtypes. Lung, adrenal, brain, and pancreatic metastases were more frequent in ccRCC, lymph node involvement was more common in pRCC, and liver metastases were more frequent in chrRCC. Median OS for ccRCC varied by site of metastatic involvement, ranging between 16 months (95% CI, 13.7-18.8 months) for the pleura and 50 months (95% CI, 41.1-55.5 months) for the pancreas. Compared with ccRCC, patients with pRCC tended to have lower OS, regardless of metastatic site.

CONCLUSIONS AND RELEVANCE

Sites of metastatic involvement differ according to histologic subtype in mRCC and are associated with OS. These data highlight the clinical and biological variability between histologic subtypes of mRCC. Patterns of metastatic spread may reflect differences in underlying disease biology. Further work to investigate differences in immune, molecular, and genetic profiles between metastatic sites and histologic subtypes is encouraged.

The effect of the papillary renal cell carcinoma subtype on oncological outcomes

The study aimed to compare the clinicopathological features and prognosis between type I and type II papillary renal cell carcinoma (PRCC) and to investigate whether the subtypes of PRCC would affect oncological outcomes. A total of 102 patients with PRCC were recruited, of which 42 were type I PRCC and 60 type II. The clinicopathological features and oncologic outcomes of the patients were evaluated. The type II cases had a higher WHO/ISUP grading (P < 0.001), T (P = 0.003), N (P = 0.010) stage and stage grouping (P = 0.011) than the type I. During a median follow-up period of 61.4 months, 1-year cancer specific survival (CSS) of the type I was 100%, 5-year CSS was 95.2%, the 1-year CSS of the type II was 96.2%, and 5-year CSS was 75.7%. The univariate analysis showed that subtype, symptoms, TNM, stage grouping, WHO/ISUP grading and surgical methods appeared to affect prognosis of the patients with PRCC. However, multivariate analysis revealed that only stage grouping was the independent risk factor. After the stage grouping factor was adjusted for the analysis, there were no statistically significant differences in CSS (P = 0.214) and PFS (P = 0.190) between the localized type I and type II PRCC groups. Compared with type I PRCC, type II had higher pathological T, N stage and WHO/ISUP grading. However, it was the Stage grouping that made a great difference to oncological outcomes, rather than the subtype of PRCC.

Comprehensive subgroup analyses of survival outcomes between clear cell renal cell adenocarcinoma and papillary renal cell adenocarcinoma

To comprehensively compare the survival outcomes of clear cell renal cell carcinoma (ccRCC) and papillary renal cell carcinoma (pRCC), the study cohort included ccRCC and pRCC patients in 2004–2017 from the Surveillance, Epidemiology, and End Results (SEER) database, which comprises 18 registries. Primary outcomes including overall mortality (OM) and cancer‐specific mortality (CSM) were evaluated. Subgroup analyses were conducted for different ages, race, and disease stages. A total of 112,270 cases were eligible for the current analysis, including 92,209 cases of ccRCC and 20,061 cases of pRCC. Univariate analyses suggested that pRCC has a more favorable outcome than ccRCC in terms of CSM (HR: 0.72, 95% CI: 0.68–0.75, p < 0.001) and OM (HR: 0.90, 95% CI: 0.88–0.93, p < 0.001). Multivariate‐adjusted HRs suggested that pRCC has worse survival outcomes than ccRCC (adjusted HR: 1.08 for CSM and 1.05 for OM, both p < 0.05). Subgroup analyses showed that pRCC had a significantly poorer prognosis than ccRCC among patients ≤45 years old (HR_CSM: 1.59, 95% CI: 1.31–1.93, p < 0.001; HR_OM: 1.63, 95% CI: 1.40–1.90, p < 0.001). Among patients with distant metastasis, those with pRCC had a higher risk of CSM and OM than those with ccRCC (HR_CSM: 1.28, 95% CI: 1.19–1.39, p < 0.001; HR_OM: 1.30, 95% CI: 1.21–1.40, p < 0.001). Propensity score analyses for patients ≤45 years old and those with metastasis showed similar results. The lack of information on pRCC subtypes in the SEER database was a limitation. In conclusion, pRCC has poorer survival outcomes than ccRCC among patients younger than 45 years old and patients with distant metastasis.

Prognostic and Predictive Factors in Metastatic Renal Cell Carcinoma: Current Perspective and a Look Into the Future

Metastatic renal cell carcinoma (mRCC) comprises a highly heterogeneous group of diseases with varied clinical outcomes. As a result, models to estimate prognosis were developed in an attempt to aid patient counseling, treatment selection, and clinical trial design. Contemporary prognostic models have been mostly generated based on clinical factors because of their ease of use. Recent advances in molecular techniques have allowed unprecedented molecular profiling of RCC and the discovery of genomic and proteotranscriptomic factors that may contribute to disease trajectory. With the advent of multiple systemic therapies in mRCC in recent years, predictive biomarkers have become increasingly relevant in treatment selection. In this review, we discuss the existing staging systems and prognostic models in mRCC. We also highlight various promising molecular biomarkers according to the subtypes of RCC and explore their integration into the traditional prognostic models. In addition, we discuss emerging predictive biomarkers in the era of immuno-oncology. Lastly, we explore future directions with a focus on liquid biopsies and composite biomarkers.

Treatment patterns, outcomes and clinical characteristics in advanced renal cell carcinoma: a real-world US study

Aim: Assessing treatment patterns, outcomes and clinical characteristics in advanced renal cell carcinoma clinical practice. Materials & methods: A US cross-sectional physician survey conducted February-September 2019. Results: Surveyed physicians reported first-line treatment of 445 patients involving tyrosine kinase inhibitor monotherapy (51.0%), immuno-oncology (IO/IO combination) therapy (25.8%) or other regimens (23.1%). A total of 60.9% had physician-assessed IMDC risk. Of these 61.9, 50.9 and 27.6% of patients with favorable, intermediate and poor risk, respectively, received tyrosine kinase inhibitor monotherapy. A total of 16.7, 26.9 and 34.5% of patients with favorable, intermediate or poor risk received IO/IO combination therapy. Complete/partial responses (∼35% patients) remained comparable across first-line treatments. Conclusion: Guideline-recommended therapies are not widely prescribed. Many patients experienced poor clinical outcomes highlighting a need for more effective treatments.

Genetic Alterations in Renal Cancers: Identification of The Mechanisms Underlying Cancer Initiation and Progression and of Therapeutic Targets

Renal cell cancer (RCC) involves three most recurrent sporadic types: clear-cell RCC (70-75%, CCRCC), papillary RCCC (10-15%, PRCC), and chromophobe RCC (5%, CHRCC). Hereditary cases account for about 5% of all cases of RCC and are caused by germline pathogenic variants. Herein, we review how a better understanding of the molecular biology of RCCs has driven the inception of new diagnostic and therapeutic approaches. Genomic research has identified relevant genetic alterations associated with each RCC subtype. Molecular studies have clearly shown that CCRCC is universally initiated by Von Hippel Lindau (VHL) gene dysregulation, followed by different types of additional genetic events involving epigenetic regulatory genes, dictating disease progression, aggressiveness, and differential response to treatments. The understanding of the molecular mechanisms that underlie the development and progression of RCC has considerably expanded treatment options; genomic data might guide treatment options by enabling patients to be matched with therapeutics that specifically target the genetic alterations present in their tumors. These new targeted treatments have led to a moderate improvement of the survival of metastatic RCC patients. Ongoing studies based on the combination of immunotherapeutic agents (immune check inhibitors) with VEGF inhibitors are expected to further improve the survival of these patients.

Polycystin-1 induces activation of the PI3K/AKT/mTOR pathway and promotes angiogenesis in renal cell carcinoma

In the present study we investigated the expression and the functional role of mechanosensitive polycystins in renal cell carcinoma (RCC). In 115 RCC patients we evaluated the protein expression of polycystin-1 (PC1), polycystin-2 (PC2), VEGF and protein components of the PI3K/Akt/mTOR pathway, which have been implicated both in RCC and polycystic kidney disease. PC1 and PC2 demonstrated reduced expression throughout the RCC tissue compared to the adjacent normal tissue. PC1 and PC2 revealed high expression when they were associated with higher grade and decreased 5-year survival respectively. PC1 and PC2 were positively correlated with p110γ subunit of PI3K and high PC1 expressing cells tended to display activation/phosphorylation of Akt. There was also a positive association between PC1 and VEGF expression, whereas PC1 augmented the tumor's microvascular network in stage IV carcinomas. In human RCC cells, functional inhibition of PC1 resulted in upregulation of the PI3K/Akt/mTOR pathway, enhanced cell proliferation and led to inhibition of cell migration. Conclusively, aberrant PC1 regulation is associated with increased angiogenesis and features of advanced disease in RCC tissues.

Bone metastasis is associated with poor prognosis in metastatic papillary renal cell carcinoma patients treated with first agent angiogenesis inhibitors

OBJECTIVE

Papillary renal cell carcinoma (papRCC) is a rare (10%-15%) subtype of renal cancer. Few prognostic biomarkers have been described in metastatic papRCC (m-papRCC) patients treated with vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKIs). We aimed to study the prognostic impact of bone metastases (BM) on response rate, progression-free and overall survival (PFS and OS) in patients with m-papRCC treated with first agent VEGFR-TKIs.

PATIENTS AND METHODS

A multicentric, retrospective analysis of patient records was conducted. BM were detected by computed tomography and/or bone scintigraphy. The International Metastatic RCC Database Consortium (IMDC) score was calculated at start of first agent VEGFR-TKI treatment.

RESULTS

Forty-nine patients were included. Best objective response was partial response in 20%, stable disease in 60% and early progressive disease in 20% of patients. Median PFS (mPFS) was 6.0 months and median OS (mOS) 14.0 months after start of first agent VEGFR-TKI. The IMDC score correlated with mOS: 77.5 months in good, 17.0 months in intermediate and 8.0 months in poor risk patients (P = 0.002). Patients with BM had a poorer outcome compared to patients without BM: mPFS was 4.0 vs. 7.0 months (P = 0.006) and mOS 7.5 vs. 19.0 months (P = 0.002). On bivariate analysis, the presence of BM was independently associated with PFS (P = 0.02) and OS (P = 0.049), independent of the IMDC risk groups.

CONCLUSION

In m-papRCC patients treated with first agent VEGFR-TKIs, the presence of BM is an unfavorable prognostic factor, associated with shorter PFS and OS.

Comparison of survival outcomes in patients with metastatic papillary vs. clear-cell renal cell carcinoma: a propensity-score analysis

BACKGROUND

To compare survival outcomes of metastatic patients harbouring either papillary (pRCC) or clear-cell (ccRCC) renal cell carcinoma in overall population and according to treatment modality.

METHODS

Within the Surveillance, Epidemiology and End Results database (2006-2015), we identified 6800 patients (585 papillary and 6215 clear-cell) with metastatic RCC. Propensity-score (PS) matching, Kaplan-Meier plots and multivariable Cox-regression models (CRMs) were used.

RESULTS

Overall, 585 (8.6%) patients harboured pRCC. Rates of nodal metastases were higher in patients with pRCC (49.7 vs. 23.3%; p < 0.001). Median overall survival (OS) was 13 vs. 18 months for pRCC vs. ccRCC patients. After multivariable adjustments, no difference in OS was recorded. Furthermore, after propensity-score matching, virtually the same results were recorded. Median OS of pRCC vs. ccRCC was 8 vs. 4 months for no treatment (NT), 11 vs. 12 months for targeted therapy alone (TT), 17 vs. 35 months for cytoreductive nephrectomy alone (CN) and 18 vs. 25 months for combination of CN with TT.

CONCLUSIONS

Metastatic pRCC patients exhibit poor survival, regardless of treatment received. Moreover, pRCC patients are more likely to present nodal metastases, compared to ccRCC patients, as demonstrated by twofold higher rates of lymph node invasion at diagnosis. These observations indicate that papillary variant represents more prognostically unfavorable tumor histology, in the context of metastatic RCC.

Synchronous Versus Metachronous Metastatic Disease: Impact of Time to Metastasis on Patient Outcome-Results from the International Metastatic Renal Cell Carcinoma Database Consortium

BACKGROUND

Patients with metastatic renal cell carcinoma (mRCC) may present with primary metastases (synchronous disease) or develop metastases during follow-up (metachronous disease). The impact of time to metastasis on patient outcome is poorly characterised.

OBJECTIVE

To characterise overall survival (OS) and time to treatment failure (TTF) based on time to metastasis in mRCC patients treated with targeted therapy (tyrosine kinase inhibitors [TKIs]).

DESIGN, SETTING, AND PARTICIPANTS

We used the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) to compare synchronous (metastases within ≤3 mo of initial diagnosis of cancer) versus metachronous disease (evaluated by >3-12 mo, >1-2 yr, >2-7 yr, and >7 yr intervals).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

OS and TFF were assessed using Kaplan-Meier curves. Cox multivariable regressions analyses (MVAs) were adjusted for baseline factors.

RESULTS AND LIMITATIONS

Of 7386 patients with mRCC treated with first-line TKIs, 3906 (53%) and 3480 (47%) had synchronous and metachronous metastasis, respectively. More patients with synchronous versus metachronous disease had higher T stage (T1-2: 19% vs 34%), N1 disease (21% vs 6%), presence of sarcomatoid differentiation (15.8% vs 7.9%), Karnofsky performance status <80 (25.9% vs 15.1%), anaemia (62.5% vs 42.3%), elevated neutrophils (18.9% vs 10.9%), elevated platelets (21.6% vs 11.4%), bone metastases (40.4% vs 29.8%), and IMDC poor risk (40.6% vs 11.3%). Synchronous versus metachronous disease by intervals >3-12 mo, >1-2 yr, >2-7 yr, and >7 yr correlated with poor TTF (5.6 mo vs 7.3, 8.0, 10.8, and 13.3 mo, p <  0.0001) and poor OS (median 16.7 mo vs 23.8, 30.2, 34.8, and 41.7 mo, p <  0.0001). In MVAs, the adjusted hazard ratios (95% confidence intervals) were 1.00 (reference), 0.98 (0.90-1.06), 0.81 (0.73-0.91), 0.74 (0.68-0.81), and 0.60 (0.54-0.67), respectively, for OS (p <  0.0001), and 1.00 (reference), 0.99 (0.92-1.06), 0.98 (0.90-1.07), 0.83 (0.77-0.89), and 0.66 (0.60-0.72), respectively, for TTF (p <  0.0001). Data were collected retrospectively.

CONCLUSIONS

Timing of metastases after initial RCC diagnosis may impact the outcomes from targeted therapy in mRCC.

PATIENT SUMMARY

We looked at the impact of the timing of metastatic outbreak on survival outcomes in kidney cancer patients treated with targeted therapy. We found that the longer time to metastatic development was associated with improved outcome.

A Review of Papillary Renal Cell Carcinoma and MET Inhibitors

 Papillary renal cell carcinoma (PRCC) is a subtype of renal cell carcinoma (RCC) accounting for approximately 15-20% of cases and further divided into Type 1 and Type 2. Type 1 PRCC tends to have more alterations in the MET tyrosine kinase receptor than Type 2 PRCC. Treatment for RCC patients is based on studies with minimal participation from patients with PRCC; consequently, conventional therapies tend to be less effective for RCC patients with a subtype other than ccRCC (non-ccRCC). Since MET is a known alteration in PRCC, it is potential target for directed therapy. There have been many attempts to develop MET inhibitors for use in solid tumors including PRCC. The following review will discuss the current research regarding MET-targeted therapy, MET inhibitors in clinical trials, and future directions for MET inhibitors in PRCC.

The VENUSS prognostic model to predict disease recurrence following surgery for non-metastatic papillary renal cell carcinoma: development and evaluation using the ASSURE prospective clinical trial cohort

BACKGROUND

The current World Health Organization classification recognises 12 major subtypes of renal cell carcinoma (RCC). Although these subtypes differ on molecular and clinical levels, they are generally managed as the same disease, simply because they occur in the same organ. Specifically, there is a paucity of tools to risk-stratify patients with papillary RCC (PRCC). The purpose of this study was to develop and evaluate a tool to risk-stratify patients with clinically non-metastatic PRCC following curative surgery.

METHODS

We studied clinicopathological variables and outcomes of 556 patients, who underwent full resection of sporadic, unilateral, non-metastatic (T1-4, N0-1, M0) PRCC at five institutions. Based on multivariable Fine-Gray competing risks regression models, we developed a prognostic scoring system to predict disease recurrence. This was further evaluated in the 150 PRCC patients recruited to the ASSURE trial. We compared the discrimination, calibration and decision-curve clinical net benefit against the Tumour, Node, Metastasis (TNM) stage group, University of California Integrated Staging System (UISS) and the 2018 Leibovich prognostic groups.

RESULTS

We developed the VENUSS score from significant variables on multivariable analysis, which were the presence of VEnous tumour thrombus, NUclear grade, Size, T and N Stage. We created three risk groups based on the VENUSS score, with a 5-year cumulative incidence of recurrence equalling 2.9% in low-risk, 15.4% in intermediate-risk and 54.5% in high-risk patients. 91.7% of low-risk patients had oligometastatic recurrent disease, compared to 16.7% of intermediate-risk and 40.0% of high-risk patients. Discrimination, calibration and clinical net benefit from VENUSS appeared to be superior to UISS, TNM and Leibovich prognostic groups.

CONCLUSIONS

We developed and tested a prognostic model for patients with clinically non-metastatic PRCC, which is based on routine pathological variables. This model may be superior to standard models and could be used for tailoring postoperative surveillance and defining inclusion for prospective adjuvant clinical trials.

Prognostic factors for the survival of patients with papillary renal cell carcinoma after surgical management

PURPOSE

To examine the possible prognostic factors in patients with type 1 and type 2 papillary renal cell carcinoma (pRCC) after surgical management and to identify the independent predictive factors of the prognosis.

METHODS

From 2010 to 2017, 1405 patients underwent surgery for renal cell carcinoma, of whom 114 had type 1 or type 2 pRCC and follow-up data were available for 88 patients. Clinicopathological and prognostic parameters were compared between type 1 and type 2 pRCC. Possible prognostic factors were retrospectively analyzed by univariate and multivariate analyses with Cox regression.

RESULTS

The study included 63 males and 25 females with a mean age of 54.27 ± 12.91. 53 patients were diagnosed by regular physical examination and others presented with hematuria or lumbago. 53 (60.2%) underwent radical nephrectomy and 35 (39.8%) underwent nephron sparing surgery. After a mean follow-up of 46.08 ± 22.65 months, 16 patients died of pRCC metastasis and the 5-year disease-specific survival was 79.3%. The comparison of the 39 (44.3%) type 1 and 49 (55.7%) type 2 pRCCs revealed that type 2 pRCC had significantly higher grade and worse prognosis. Univariate analysis showed that symptomatic diagnosis, type, grade, and tumor stage were prognostic factors. Multivariate analysis identified that type and tumor stage were independent factors of the prognosis.

CONCLUSIONS

Pathological type and tumor stage could serve as independent factors for the prognosis of patients with pRCC.

A comparison of the prognosis of papillary and clear cell renal cell carcinoma: Evidence from a meta-analysis

OBJECTIVE

To compare the prognosis of papillary and clear cell renal cell carcinoma (RCC) in order to determine the optimal follow-up and therapy for patients with RCC.

METHODS

A systematic search of Web of Science, EMBASE, Cochrane Library, and PubMed databases was conducted for articles published through July 30, 2018, reporting on a comparison of the prognosis of papillary RCC and clear cell RCC using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.

RESULTS

Of 1896 studies, 11 were considered for the evidence synthesis. A total of 35,832 patients were included. Of these patients, 6907 patients were diagnosed with papillary renal cell carcinoma, and 28,925 patients were diagnosed with clear cell renal cell carcinoma. The prognosis of papillary RCC was better than that of clear cell RCC (hazard ratio (HR) = 0.50; 95% confidence interval (CI) 0.45 to 0.56; P < .001; I = 91.9%). A subgroup analysis indicated that papillary RCC was associated with better outcomes (HR = 0.76, 95% CI 0.50-1.16), and a trend toward a higher risk of mortality was observed in patients with metastatic RCC presenting with papillary histology, but the difference was not statistically significant (HR = 1.12, 95% CI 0.71-1.76, P = .085). Pooled data suggested a lack of a significant difference between papillary RCC (p-RCC) type 1 and clear cell RCC (cc-RCC) (HR = 0.30, 95% CI 0.12-0.73, P = .085). The pooled HR for the prognosis of p-RCC type 2 compared to cc-RCC was 1.69 (95% CI 0.93-3.08; P = .032).

CONCLUSION

Papillary RCC is associated with better outcomes than clear cell RCC in patients without metastases, but not in patients with metastases. Optimal follow-up or therapy for patients with RCC should be assigned according to the tumor stage and subtype.

Cytoreductive Nephrectomy in Metastatic Papillary Renal Cell Carcinoma: Results from the International Metastatic Renal Cell Carcinoma Database Consortium

BACKGROUND

There is evidence that cytoreductive nephrectomy (CN) may be beneficial in metastatic renal cell carcinoma (mRCC). This has been studied predominantly in clear-cell RCC, with more limited data on the role of CN in patients with papillary histology.

OBJECTIVE

To determine the benefit of CN in synchronous metastatic papillary RCC.

DESIGN, SETTING, AND PARTICIPANTS

Using the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) database, a retrospective analysis was performed for patients with papillary mRCC treated with or without CN.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Median overall survival (OS) and progression-free survival (PFS) were determined for both patient groups. Cox regression analysis was performed to control for imbalances in individual IMDC risk factors.

RESULTS AND LIMITATIONS

In total, 647 patients with papillary mRCC were identified, of whom 353 had synchronous metastatic disease. Of these, 109 patients were treated with CN and 244 were not. The median follow-up was 57.1mo (95% confidence interval [CI] 32.9-77.8) and the OS from the start of first-line targeted therapy for the entire cohort was 13.2mo (95% CI 12.0-16.1). Median OS for patients with CN was 16.3mo, compared to 8.6mo (p<0.0001) in the no-CN group. When adjusted for individual IMDC risk factors, the hazard ratio (HR) of death for CN was 0.62 (95% CI 0.45-0.85; p=0.0031). Limitations include the retrospective nature of the analysis.

CONCLUSIONS

The use of CN in patients with mRCC and papillary histology appears to be associated with better survival compared to no CN after adjustment for risk criteria. Selection of appropriate candidates for CN is crucial. A clinical trial in this rare population may not be possible.

PATIENT SUMMARY

In a population of patients with advanced papillary kidney cancer, we found that surgical removal of the primary kidney tumor was associated with better overall survival.

Metastatic papillary renal cell carcinoma in the era of targeted therapy - a retrospective study from three European academic centres

BACKGROUND

Metastatic papillary renal cell carcinoma (mPRCC) is understudied. The disease is often aggressive and specific treatment options are lacking.

PATIENTS AND METHODS

mPRCC patients (n = 86) referred to three academic centres in Sweden and Germany in the years 2005-2015 were retrospectively identified from medical records. Statistical analyses included Kaplan-Meier curves and calculation of Cox proportional hazards, generating hazard ratios with 95% confidence intervals. The aim of the study was to evaluate overall survival (OS) of mPRCC patients treated outside of clinical trials in the era of targeted agents (TA) and to identify clinically useful prognostic factors.

RESULTS

Median OS of all mPRCC patients was 11.2 months. TA were used in 77% of the patients and associated with younger age and better Eastern Cooperative Oncology Group performance status (PS). Brain metastases were common (28%). Patients with synchronous or metachronous metastases had similar OS. Variables independently associated with risk of death included age ≥60 years, worse PS and ≥3 metastatic sites. The MSKCC criteria did not provide additional prognostic information. A subgroup analysis of TA-treated patients revealed an association of lymph node metastasis with risk of death in addition to the other prognostic factors.

CONCLUSION

OS in mPRCC remained short in the era of targeted agents. Age, PS, and number of metastatic sites provided independent prognostic information.

Successful treatment with sorafenib for sunitinib-refractory metastatic papillary renal cell carcinoma: Potential impact of Raf overexpression on predicting the efficacy of sorafenib

Introduction

The prognosis of type 2 papillary renal cell carcinoma is often poor. We herein report a case of papillary renal cell carcinoma with liver metastasis that was successfully treated with sorafenib as a second‐line therapy.

Case presentation

An 82‐year‐old man who had undergone radical nephrectomy 5 years previously experienced biopsy‐proven liver metastasis. He received sunitinib as a first‐line treatment; the dose was initially 12.5 mg/day and was escalated to 25 mg/day, but it was discontinued due to several adverse events. We then switched to sorafenib as a second‐line treatment, which resulted in a partial response (51% reduction in tumor size); the patient showed no recurrence 5 months after the initiation of sorafenib treatment. An immunohistochemical analysis revealed the overexpression of Raf in both the primary and metastatic tumors.

Conclusion

As sorafenib blocks Raf signaling, the expression of Raf may serve as a useful predictor of the efficacy of sorafenib.

Prognostication in Kidney Cancer: Recent Advances and Future Directions

The most common type of cancer originating in the kidney is renal cell carcinoma (RCC). In both localized and advanced RCC, a number of clinical, pathologic, and molecular factors have been identified as having prognostic significance. In localized disease, risk stratification has traditionally involved the anatomic extent of disease, and several integrated scoring systems have been developed to help predict outcomes after definitive local therapy. In metastatic RCC, integrated prognostic models have also been established. These are used to stratify patients in contemporary clinical trials and to guide risk-directed treatment selection in clinical practice. Although many prognostic factors are common to both localized and advanced disease, there are some important distinctions. In both of these types of disease, the prognostic role of specific molecular and genomic alterations is an area of active investigation. In this review, we highlight the current staging systems and prognostic factors in localized and metastatic RCC. We also explore future directions in this area, including the expanding role of molecular biomarkers and their integration into the traditional prognostic models.

Characterizing the outcomes of metastatic papillary renal cell carcinoma

Outcomes of metastatic papillary renal cell carcinoma (pRCC) patients are poorly characterized in the era of targeted therapy. A total of 5474 patients with metastatic renal cell carcinoma (mRCC) in the International mRCC Database Consortium (IMDC) were retrospectively analyzed. Outcomes were compared between clear cell (ccRCC; n = 5008) and papillary patients (n = 466), and recorded type I and type II papillary patients (n = 30 and n = 165, respectively). Overall survival (OS), progression-free survival (PFS), and overall response rate (ORR) favored ccRCC over pRCC. OS was 8 months longer in ccRCC patients and the hazard ratio of death was 0.71 for ccRCC patients. No differences in PFS or ORR were detected between type I and II PRCC in this limited dataset. The median OS for type I pRCC was 20.0 months while the median OS for type II was 12.6 months (P = 0.096). The IMDC prognostic model was able to stratify pRCC patients into favorable risk (OS = 34.1 months), intermediate risk (OS = 17.0 months), and poor-risk groups (OS = 6.0 months). pRCC patient outcomes were inferior to ccRCC, even after controlling for IMDC prognostic factors. The IMDC prognostic model was able to effectively stratify pRCC patients.