Comparison of oncologic outcomes between sarcomatoid and clear cell renal cell carcinoma

Trends and Outcomes in Sarcomatoid Renal Cell Carcinoma: Analysis of the National Cancer Data Base

Background and objective

Our aim was to determine the clinical characteristics, temporal trends, and survival outcomes for sarcomatoid-dedifferentiated renal cell carcinoma (sRCC), as sRCC has historically had poor prognosis and a contemporary cohort has not been well characterized in a population-based study.

Methods

Data for 302 630 RCC cases from 2010 to 2019 were extracted from the National Cancer Data Base, of which 4.1% (12 329) were sRCC. Trend analyses were conducted using the Cochran-Armitage test. Multivariable analyses were used to assess factors associated with sRCC diagnosis and clinicopathologic characteristics associated with all-cause mortality (ACM). Overall survival (OS) was computed via Kaplan-Meier analysis.

Key findings and limitations

sRCC incidence increased from 3.9% in 2010 to 4.1% in 2019 (p = 0.020). The incidence of stage I sRCC increased from 14.5% in 2010 to 19.2% in 2019 (p < 0.001). sRCC diagnosis was associated with male sex, tumor size, cN1 status, and collecting duct histology. Worse ACM in localized sRCC was associated with age, tumor size, cN1 stage, collecting duct histology, and positive surgical margins; and was inversely associated with partial nephrectomy (hazard ratio [HR] 0.61, 95% confidence interval [CI] 0.49-0.76; p < 0.001). Worse ACM in metastatic sRCC was associated with age, tumor size, cN1, collecting duct histology, positive surgical margins, and no surgery at the primary site (HR 1.66, 95% CI 1.20-2.30; p = 0.006). The 5-yr OS rates for stage I, stage II, stage III, and stage IV sRCC were 74%, 63%, 42%, and 16%, respectively (p < 0.001).

Conclusions and clinical implications

The proportion of sRCC cases overall and of stage I sRCC cases increased from 2010 to 2019, supporting the hypothesis of stage migration and the potential for early sarcomatoid dedifferentiation. Further studies on the causal mechanisms underpinning better survival after partial nephrectomy in localized disease and after cytoreductive surgery in metastatic disease are warranted.

Patient summary

We analyzed trends and outcomes for a type of aggressive kidney cancer (sarcomatoid renal cell carcinoma, sRCC) using records from the National Cancer Data Base. We found that the percentage of sRCC cases among all kidney cancers increased from 2010 to 2019. Factors such as tumor size and patient age were linked to worse survival. Surgery to remove the cancer was linked to better survival.

Sarcomatoid and Rhabdoid Renal Cell Carcinoma: Clinical, Pathologic, and Molecular Genetic Features

Renal cell carcinoma (RCC) with sarcomatoid and rhabdoid morphologies has an aggressive biological behavior and a typically poor prognosis. The current 2022 WHO classification of renal tumors does not include them as distinct histologic entities but rather as transformational changes that may arise in a background of various distinct histologic types of RCC. The sarcomatoid component shows malignant spindle cells that may grow as intersecting fascicles, which is reminiscent of pleomorphic undifferentiated sarcoma. The rhabdoid cells are epithelioid cells with eccentrically located vesicular nuclei with prominent nucleoli and large intracytoplasmic eosinophilic inclusions. Studies have shown that RCCs with sarcomatoid and rhabdoid differentiation have distinctive molecular features. Sarcomatoid RCC harbors shared genomic alterations in carcinomatous and rhabdoid components, but also enrichment of specific genomic alterations in the sarcomatoid element, suggesting molecular pathways for development of sarcomatoid growth from a common clonal ancestor. Rhabdoid differentiation also arises through clonal evolution although less is known of specific genomic alterations in rhabdoid cells. Historically, treatment has lacked efficacy, although recently immunotherapy with PD-1/PD-L1/CTLA-4 inhibitors has produced significant clinical responses. Reporting of sarcomatoid and rhabdoid features in renal cell carcinoma is required by the College of American Pathologists and the International Collaboration on Cancer Reporting. This manuscript reviews the clinical, pathologic, and molecular features of sarcomatoid RCC and rhabdoid RCC with emphasis on the morphologic features of these tumors, significance of diagnostic recognition, the molecular mechanisms of tumorigenesis and differentiation along sarcomatoid and rhabdoid lines, and advances in treatment, particularly immunotherapy.

Renal Cell Carcinoma of Variant Histology: New Biologic Understanding Leads to Therapeutic Advances

Renal cell carcinoma (RCC) is one of the 10 most commonly diagnosed solid tumors. Most RCCs are histologically defined as clear cell, comprising approximately 75% of diagnoses. However, the remaining RCC cases are composed of a heterogeneous combination of diverse histopathologic subtypes, each with unique pathogeneses and clinical features. Although the therapeutic approach to both localized and metastatic RCCs has dramatically changed, first with the advent of antiangiogenic targeted therapies and more recently with the approval of immune checkpoint inhibitor (ICI)-based combinations, these advances have primarily benefited the clear cell RCC patient population. As such, there remains critical gaps in the optimization of treatment regimens for patients with non-clear cell, or variant, RCC histologies. Herein, we detail recent advances in understanding the biology of RCC with variant histology and how such findings have guided novel clinical studies investigating precision oncology approaches for these rare subtypes. Among the most common variant histology RCCs are papillary RCC, comprising approximately 15%-20% of all diagnoses. Although a histopathologically diverse subset of tumors, papillary RCC is canonically associated with amplification of the MET protooncogene; recently completed and ongoing trials have investigated MET-directed therapies for this patient population. Finally, we discuss the unique biology of RCC with sarcomatoid dedifferentiation and the recent clinical findings detailing its paradoxical sensitivity to ICIs.

Renal cell carcinoma and venous tumor thrombus: predicting sarcomatoid dedifferentiation through preoperative IVIM-based MR imaging

PURPOSE

To evaluate the value of preoperative intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) and conventional MRI indicators in identifying sarcomatoid dedifferentiation in renal cell carcinoma (RCC) and tumor thrombus.

METHODS

From September 2016 to April 2023, consecutive patients with RCC and tumor thrombus who received routine MRI examination and IVIM-DWI before radical resection were enrolled prospectively. Kaplan-Meier method with log-rank test was used to calculate and compare the survival probability. The preoperative imaging features were analyzed. Univariate and multivariable logistic regression analyses were employed to identify independent predictors of sarcomatoid dedifferentiation. The predictive ability was evaluated by receiver operating characteristic (ROC) curves.

RESULTS

Twenty-two patients (15.3%) of the 144 patients in the training set (median age, 58.0 years [IQR, 52.0-65.0 years]; 108 men) and 11 patients (22.4%) of the 49 patients in the test set (median age, 58.0 years [IQR, 53.0-63.0 years]; 38 men) had sarcomatoid dedifferentiated tumors. Patients with sarcomatoid-differentiated tumors had poor progress-free survival in the training set and test set (P < 0.001 and P = 0.007). f value (P = 0.011), mN stage (P = 0.007), and necrosis (P = 0.041) were independent predictors for predicting sarcomatoid dedifferentiation in the training set. The model combining conventional MRI features and f value had AUCs of 0.832 (95% CI 0.755-0.909) and 0.825 (95% CI 0.702-0.948) in predicting sarcomatoid dedifferentiation in the training set and test set.

CONCLUSION

It is feasible to preoperatively identify sarcomatoid dedifferentiation based on IVIM-DWI and conventional MR imaging indicators.

Localised non-metastatic sarcomatoid renal cell carcinoma: a 31-year externally verified study

OBJECTIVE

To evaluate post-nephrectomy outcomes and predictors of cancer-specific survival (CSS) between patients with localised sarcomatoid renal cell carcinoma (sRCC) and those with Grade 4 RCC (non-sRCC), as most sRCC research focuses on advanced or metastatic disease with limited studies analysing outcomes of patients with localised non-metastatic sRCC.

PATIENTS AND METHODS

A total of 564 patients with localised RCC underwent partial or radical nephrectomy between June 1988 to March 2019 for sRCC (n = 204) or World Health Organization/International Society of Urological Pathology Grade 4 non-sRCC (n = 360). The CSS at every stage between groups was assessed. Phase III ASSURE clinical trial data were used to externally validate the CSS findings. The Mann-Whitney U-test and chi-squared test compared outcomes and the Kaplan-Meier method evaluated CSS, overall survival (OS) and recurrence-free survival. Clinicopathological features associated with RCC death were evaluated using Cox proportional hazards regression.

RESULTS

The median follow-up was 31.5 months. The median OS and CSS between the sRCC and Grade 4 non-sRCC groups was 45 vs 102 months and 49 vs 152 months, respectively (P < 0.001). At every stage, sRCC had worse CSS compared to Grade 4 non-sRCC. Notably, pT1 sRCC had worse CSS than pT3 Grade 4 non-sRCC. Negative predictors of CSS were sarcomatoid features, non-clear cell histology, positive margins, higher stage (pT3/pT4), and use of minimally invasive surgery (MIS). ASSURE external verification showed worse CSS in patients with sRCC (hazard ratio [HR] 1.63, 95% confidence interval [CI] 1.12-2.36; P = 0.01), but not worse outcomes in MIS surgery (HR 1.39, 95% CI 0.75-2.56; P = 0.30).

CONCLUSIONS

Localised sRCC had worse CSS compared to Grade 4 non-sRCC at every stage. Negative survival predictors included positive margins, higher pathological stage, use of MIS, and non-clear cell histology. sRCC is an aggressive variant even at low stages requiring vigilant surveillance and possible inclusion in adjuvant therapy trials.

Sarcomatoid renal cell carcinoma: MRI features and their association with survival

OBJECTIVE

To evaluate MRI features of sarcomatoid renal cell carcinoma (RCC) and their association with survival.

METHODS

This retrospective single-center study included 59 patients with sarcomatoid RCC who underwent MRI before nephrectomy during July 2003-December 2019. Three radiologists reviewed MRI findings of tumor size, non-enhancing areas, lymphadenopathy, and volume (and percentage) of T2 low signal intensity areas (T2LIA). Clinicopathological factors of age, gender, ethnicity, baseline metastatic status, pathological details (subtype and extent of sarcomatoid differentiation), treatment type, and follow-up were extracted. Survival was estimated using Kaplan-Meier method and Cox proportional-hazards regression model was used to identify factors associated with survival.

RESULTS

Forty-one males and eighteen females (median age 62 years; interquartile range 51-68) were included. T2LIAs were present in 43 (72.9%) patients. At univariate analysis, clinicopathological factors associated with shorter survival were: greater tumor size (> 10 cm; HR [hazard ratio] = 2.44, 95% CI 1.15-5.21; p = 0.02), metastatic lymph nodes (present; HR = 2.10, 95% CI 1.01-4.37; p = 0.04), extent of sarcomatoid differentiation (non-focal; HR = 3.30, 95% CI 1.55-7.01; p < 0.01), subtypes other than clear cell, papillary, or chromophobe (HR = 3.25, 95% CI 1.28-8.20; p = 0.01), and metastasis at baseline (HR = 5.04, 95% CI 2.40-10.59; p < 0.01). MRI features associated with shorter survival were: lymphadenopathy (HR = 2.24, 95% CI 1.16-4.71; p = 0.01) and volume of T2LIA (> 3.2 mL, HR = 4.22, 95% CI 1.92-9.29); p < 0.01). At multivariate analysis, metastatic disease (HR = 6.89, 95% CI 2.79-16.97; p < 0.01), other subtypes (HR = 9.50, 95% CI 2.81-32.13; p < 0.01), and greater volume of T2LIA (HR = 2.51, 95% CI 1.04-6.05; p = 0.04) remained independently associated with worse survival.

CONCLUSION

T2LIAs were present in approximately two thirds of sarcomatoid RCCs. Volume of T2LIA along with clinicopathological factors were associated with survival.

The Natural History of Renal-Cell Carcinoma with Sarcomatoid Differentiation, a Stage-by-Stage Analysis

BACKGROUND

Sarcomatoid differentiation in patients diagnosed with renal cell carcinoma (sRCC) imply aggressive behavior and often metastatic disease at the time of diagnosis. We aim to examine the overall survival (OS) in patients with sRCC using the National Cancer Database (NCDB).

MATERIALS AND METHODS

We identified patients diagnosed with sRCC between 2010-2015. We employed Kaplan-Meier curves and multivariable Cox proportional hazards regression models to examine the impact of several potential risk factors on OS in patients diagnosed with sRCC.

RESULTS

In total, 8582 patients with renal cancer were found to have sarcomatoid differentiation, with 4105 patients (47.8%) being diagnosed with AJCC stage IV disease. The median OS was 17.2 months (IQR 5.4, 68.7 months). Compared to patients who did not undergo surgery, OS was significantly longer in patients undergoing partial or total nephrectomy across all stages. This result remained consistent on multivariable Cox proportional hazards regression adjusting for patient and tumor characteristics (Surgery: Hazard ratio 0.54, 95%Confidence interval 0.43 - 0.68, P < .001).

CONCLUSION

In our cohort sRCC was found to have an unfavorable median OS, which was mainly caused by the high number of cases diagnosed with late-stage disease. Additionally, surgery was associated with favorable OS across all stages. This study supports the notion that surgical therapy, even in the setting of cytoreductive surgery, provides a survival benefit in patients with sRCC.

The significance of sarcomatoid and rhabdoid dedifferentiation in renal cell carcinoma

Dedifferentiation in renal cell carcinoma (RCC), either sarcomatoid or rhabdoid, is an infrequent event that may occur heterogeneously in the setting of any RCC histology and is associated with poor outcomes. Sarcomatoid dedifferentiation is associated with inferior survival with angiogenesis targeted therapy and infrequent responses to cytotoxic chemotherapy. However, immune checkpoint therapy has significantly improved outcomes for patients with sarcomatoid dedifferentiation. Biologically, sarcomatoid dedifferentiation has increased programmed death-ligand 1 (PD-L1) expression and an inflamed tumor microenvironment, in addition to other distinct molecular alterations. Less is known about rhabdoid dedifferentiation from either a clinical, biological, or therapeutic perspective. In this focused review, we will discuss the prognostic implications, outcomes with systemic therapy, and underlying biology in RCC with either sarcomatoid or rhabdoid dedifferentiation present.

Influence of Deep Invasive Tumor Thrombus on the Surgical Complexity and Prognosis of Patients With Non-Metastatic Renal Cell Carcinoma Combined With Venous Tumor Thrombus

BACKGROUND

To evaluate the impact of deep invasive tumor thrombus (DITT) on the surgical complexity and prognosis of patients with renal cell carcinoma with venous tumor thrombus.

METHODS

We retrospectively reviewed clinical data of 138 patients with non-metastatic renal cell carcinoma combined with venous tumor thrombus, who underwent surgical treatment in Peking University Third Hospital from January 2015 to June 2020. Patients were divided into the DITT group (84 patients) and non-invasive tumor thrombus (NITT) group (54 patients). Chi-square, t-test and Mann-Whitney U test were used for categorical and continuous variables, respectively. Kaplan-Meier plots were performed to evaluate the influence of DITT. Univariable and multivariable Cox regressions were conducted to determine independent prognostic factors and then assembled to make a nomogram to predict the survival. The performance of the nomogram was evaluated by Harrell's consistency index (C-index) and calibration plot.

RESULTS

Deep invasive tumor thrombus significantly increased the difficulty of surgery for patients with renal cell carcinoma with venous tumor thrombus, which is mainly reflected in longer operation time (p < 0.001), more surgical bleeding (p  < 0.001), a higher proportion of perioperative blood transfusion (p  = 0.006), a higher proportion of open surgery (p = 0.001), a longer postoperative hospital stay (p = 0.003), and a higher proportion of postoperative complications (p = 0.001). DITT (hazard ratio [HR] = 2.781, p = 0.040) was one of the independent risk factors for worse prognosis. Multivariate analysis showed that sarcoma-like differentiation (p = 0.040), tumor thrombus invasion (p = 0.040), low hemoglobin (p = 0.003), and pathological type (p < 0.001) were independent prognostic factors. The nomogram, combining all these predictors, showed powerful prognostic ability with a C-index of 78.8% (CI: 71.2%-86.4%). The predicted risk closely matches the observed recurrence probability.

CONCLUSION

Deep invasive tumor thrombus significantly increased the difficulty of surgeries for patients of renal cell carcinoma with venous tumor thrombus, and may lead to poor prognosis.

Prognostic Factors for Localized Clear Cell Renal Cell Carcinoma and Their Application in Adjuvant Therapy

Simple Summary

Approximately one fifth of patients with newly diagnosed renal cell carcinoma (RCC) present with metastatic disease and over one third of the remaining patients with localized RCC will eventually have metastases spread to distant sites after complete resection of the primary tumor in the kidney. Usually, disease recurrence is observed within the first five years of follow-up, but late recurrences after five years are seen in up to 10% of patients. Despite novel biomarkers, simple histopathological factors, such as tumor size, tumor grade, and tumor extension into the blood vessels or beyond the kidney, are still valid features in predicting the risk of disease recurrence after surgery. The optimal set of prognostic factors remains unclear. The results from ongoing placebo-controlled adjuvant therapy trials may elucidate prognostic features that help to define high-risk patients for disease recurrence.

Abstract

Approximately 20% of patients with renal cell carcinoma (RCC) present with primarily metastatic disease and over 30% of patients with localized RCC will develop distant metastases later, after complete resection of the primary tumor. Accurate postoperative prognostic models are essential for designing personalized surveillance programs, as well as for designing adjuvant therapy and trials. Several clinical and histopathological prognostic factors have been identified and adopted into prognostic algorithms to assess the individual risk for disease recurrence after radical or partial nephrectomy. However, the prediction accuracy of current prognostic models has been studied in retrospective patient cohorts and the optimal set of prognostic features remains unclear. In addition to traditional histopathological prognostic factors, novel biomarkers, such as gene expression profiles and circulating tumor DNA, are extensively studied to supplement existing prognostic algorithms to improve their prediction accuracy. Here, we aim to give an overview of existing prognostic features and prediction models for localized postoperative clear cell RCC and discuss their role in the adjuvant therapy trials. The results of ongoing placebo-controlled adjuvant therapy trials may elucidate prognostic factors and biomarkers that help to define patients at high risk for disease recurrence.

Sarcomatoid Renal Cell Carcinoma: The Present and Future of Treatment Paradigms

Sarcomatoid renal cell carcinoma (sRCC) is an aggressive form of kidney cancer that is associated with poor prognosis. It can arise from any histologic type of renal cell carcinoma. The majority of cases will present with advanced or metastatic disease requiring systemic therapy. Nephrectomy is the treatment of choice in locally resectable disease. The therapeutic options for sRCC have evolved in the past decade. Cytotoxic chemotherapy and monotherapy with targeted therapy (VEGF and mTOR) have historically shown poor response rates and survival in the treatment of metastatic sRCC. The use of checkpoint inhibitors and their combination with targeted therapy against VEGF has changed the landscape and outcomes for renal cell carcinoma. Given the rarity of sRCC most of the data on treatment is from small cohorts or extrapolation from larger clinical trials. The benefit from the combination of checkpoint inhibitors and targeted therapy to VEGF has shown promise in the sRCC population in post hoc analysis of large clinical trials. Future research focusing on further characterizing the unique biologic and clinical features of sRCC is critical in advancing the knowledge and developing effective therapy to improve clinical outcomes and survival.

Sarcomatoid renal cell carcinoma: biology, natural history and management

Sarcomatoid dedifferentiation is an uncommon feature that can occur in most histological subtypes of renal cell carcinomas (RCCs) and carries a decidedly poor prognosis. Historically, conventional treatments for sarcomatoid RCCs (sRCCs) have shown little efficacy, and median survival is commonly 6–13 months. Despite being first described in 1968, the mechanisms driving sarcomatoid dedifferentiation remain poorly understood, and information and treatment options available to physicians and patients are limited. When diagnosed at an early stage, surgical intervention remains the treatment of choice. However, preoperative identification through routine imaging or biopsy is unreliable and most patients present with advanced disease and systemic symptoms. For these patients, the role of cytoreductive nephrectomy is disputed. The expansion of immunotherapies approved for RCCs has generated a search for biomarkers that might be indicative of treatment response in sRCCs, although a proven effective systemic agent remains elusive. PDL1 expression is increased in sarcomatoid dedifferentiated renal tumours, which suggests that patients with sRCCs could benefit from PD1 and/or PDL1 immune checkpoint blockade therapy. Treatment outcomes for sarcomatoid tumours have remained relatively consistent compared with other RCCs, but further investigation of the tumour–immune cell microenvironment might yield insights into further therapeutic possibilities.

In this Review, Blum et al. summarize the current knowledge on sarcomatoid renal cell carcinoma, a diagnosis characterized by the presence of sarcomatoid dedifferentiation and a poor prognosis. They discuss the origin, presentation, molecular biology and treatment of this disease.

Sarcomatoid dedifferentiation is not considered to be a unique histological subtype of renal cell carcinomas (RCCs); rather, it can be present within any subtype of RCCs.

Sarcomatoid dedifferentiation appears in ~4% of all RCCs, but is present in ~20% of all metastatic RCCs. According to WHO guidelines, any RCC with sarcomatoid dedifferentiation is a WHO–International Society of Urological Pathology grade 4 lesion.

Sarcomatoid dedifferentiation is often heterogeneously present within RCCs, making routine imaging and biopsy unreliable for preoperative detection. Surgical resection for localized disease is the standard of care, with subsequent close monitoring of patients following surgery.

In patients with metastatic disease, conventional therapies such as surgery and systemic agents have been ineffective and overall 5-year survival remains at 23.5–33%.

Previous genomic analyses have failed to identify definitive mutational drivers of disease. However, sarcomatoid RCCs (sRCCs) have been shown to have higher PD1 and PDL1 expression than other subtypes of RCCs. Newer combinations of immune checkpoint inhibitor immunotherapies could yield improved responses and outcomes.

Studies investigating sRCCs are limited by patient numbers owing to the low incidence of sRCCs and their advanced stage at presentation. Multi-institutional efforts to establish a consensus on treatment recommendations based on highly powered data are essential.

Impact of sarcomatoid differentiation and rhabdoid differentiation on prognosis for renal cell carcinoma with vena caval tumour thrombus treated surgically

Background

Sarcomatoid differentiation in renal cell carcinoma (RCC) with vena caval tumour thrombus has been shown to be associated with aggressive behaviours and poor prognosis; however, evidence of the impact of rhabdoid differentiation on prognosis is lacking. This study evaluated the impact of sarcomatoid differentiation and rhabdoid differentiation on oncological outcomes for RCC with vena caval tumour thrombus treated surgically.

Methods

We retrospectively analysed patients treated surgically for RCC with vena caval tumour thrombus at our institute from Jan 2015 to Nov 2018. Prognostic variables were evaluated for associations with progression-free survival (PFS) and cancer-specific survival (CSS) by Kaplan–Meier survival analysis and log-rank test. Univariate and multivariate analyses were performed to determine independent prognostic variables.

Results

We identified 125 patients with RCC and vena caval tumour thrombus, including 17 (13.6%) with sarcomatoid differentiation alone, 8 (6.4%) with rhabdoid differentiation alone and 3 (2.4%) with both sarcomatoid and rhabdoid differentiation. Compared to pure RCC, patients with sarcomatoid differentiation but not rhabdoid differentiation have worse PFS (p = 0.018 and p = 0.095, respectively). The univariate and multivariate analyses both showed sarcomatoid differentiation as a significant predictor of PFS. Compared to pure RCC, patients with sarcomatoid differentiation (p = 0.002) and rhabdoid differentiation (p = 0.001) both had significantly worse CSS. The univariate analysis showed sarcomatoid differentiation, rhabdoid differentiation, metastasis and blood transfusion as significant predictors of CSS (All, p < 0.05). In the multivariate analysis, sarcomatoid differentiation (HR 3.90, p = 0.008), rhabdoid differentiation (HR 3.01, p = 0.042), metastasis (HR 3.87, p = 0.004) and blood transfusion (HR 1.34, p = 0.041) all remained independent predictors of CSS.

Conclusions

Sarcomatoid differentiation and rhabdoid differentiation are both independent predictors of poor prognosis in RCC with vena caval tumour thrombus treated surgically.

Histologic Subtype, Tumor Grade, Tumor Size, and Race Can Accurately Predict the Probability of Synchronous Metastases in T2 Renal Cell Carcinoma

BACKGROUND

We investigated the association between synchronous metastases (SMs), histologic subtype (HS), tumor size (TS), and tumor grade (TG) in surgically treated stage T2 renal cell carcinoma (RCC).

MATERIALS AND METHODS

Within the Surveillance, Epidemiology, and End Results database (2005-2015), 8344 patients with T2 RCC who had undergone radical nephrectomy were identified. The SM rates were tabulated according to the HS, TG, and TS and tested in multivariable logistic regression models.

RESULTS

According to the HS, the average SM rates were 0%, 1.4%, 4.6%, 6.4%, 12.7%, 20.0%, and 32.7% for multilocular cystic, chromophobe, papillary, TG 1-2 clear cell, TG 3-4 clear cell, collecting duct, and sarcomatoid dedifferentiation RCC, respectively. In multivariable logistic regression models predicting for SMs, HS represented the strongest predictor, followed by TG, TS, and race. When combined, HS, TG, TS, and race predicted for SMs with 70.2% accuracy compared with 62.5% with HS, 60.2% with TG, 57.8% with TS, and 53.0% with race alone. Lung only was the most common metastatic site (43.6%), followed by bone only (27.6%), liver only (4.4%), and brain only (4.4%). Of all the patients with SMs, 78.9% had a single metastatic site.

CONCLUSIONS

The SM rates showed very wide variation according to the HS, TG, and TS. When HS was combined with TG, TS, and race, SMs could be accurately predicted in individual patients better than with TS alone. Thus, renal mass biopsy-derived HS and TG could improve the prediction of SMs compared with using TS alone.

Risk factors associated with suicide among kidney cancer patients: A Surveillance, Epidemiology, and End Results analysis

Background

The suicide risk was higher in kidney cancer patients than in the general population. The purpose of this study was to characterize the suicide rates among kidney cancer patients and to identify the potential risk factors associated with suicide from the Surveillance, Epidemiology, and End Results (SEER) database.

Methods

Kidney cancer patients were identified from the SEER database during 1973‐2015. Suicide rates and standardized mortality ratios (SMRs) of this population were calculated, and the US general population during 1981‐2015 was chosen as a reference. Univariable and multivariable Cox regression were performed to find out potential risk factors of suicide.

Results

There were 207 suicides identified among 171 819 individuals with kidney cancer observed for 948 272 person‐years. The suicide rate was 21.83 per 100 000 person‐years, and SMR was 1.83 (95% CI: 1.59‐2.10). On Cox regression, diagnosis in early years (1973‐1982 vs 2003‐2015, HR: 2.03, 95% CI: 1.01‐4.11, P = 0.048; 1983‐1992 vs 2003‐2015, HR: 1.99, 95% CI: 1.18‐3.35, P = 0.010), male sex (vs female sex, HR: 4.43, 95% CI: 2.95‐6.65, P < 0.001), unmarried status (vs married status, HR: 2.54, 95% CI: 1.91‐3.38, P < 0.001), non‐black race (white race vs black race, HR: 4.47, 95% CI: 2.09‐9.58, P < 0.001; other races vs black race, HR: 3.01, 95% CI: 1.08‐8.37, P = 0.035), higher histologic grade (grade IV vs grade I, HR: 3.27, 95% CI: 1.50‐7.13, P = 0.003; grade III vs grade I, HR: 2.13, 95% CI: 1.19‐3.81, P = 0.011) and cancer‐directed surgery not performed (vs performed, HR: 2.78, 95% CI: 1.52‐5.11, P < 0.001) were independent risk factors of suicide among kidney cancer patients.

Conclusions

Diagnosis in early years, male sex, unmarried status, non‐black race, higher histologic grade, and cancer‐directed surgery not performed were significantly associated with suicide among kidney cancer patients. In order to prevent suicidal death, clinicians should pay more attention to patients with high‐risk factors of suicide.

Patterns of Presentation and Treatment Outcomes of Non-clear-cell Renal Cell Carcinoma and Sarcomatoid Renal Cell Carcinoma Patients in 2 Tertiary Referral Centers in Sydney, Australia

BACKGROUND

Non-clear-cell renal cell carcinoma (nccRCC) and renal cell carcinoma with sarcomatoid features (scRCC) are rare, and represent subtypes with less defined treatment strategies. The aim of this study is to describe the patterns of care and outcomes of these patients in 2 tertiary referral centers in South Western Sydney Local Health District over a 10-year period.

PATIENTS AND METHODS

Patients with RCC seen at South Western Sydney Local Health District from January 1, 2005 to December 31, 2015 were identified from electronic medical records. For each patient, we extracted details regarding demographics, tumor characteristics, treatment, recurrences, and survival, which was analyzed using the Kaplan-Meier method.

RESULTS

Of 178 patients with RCC identified between 2005 and 2015, 23% (n = 41) had nccRCC and 8% (n = 15) had scRCC. Twenty-five patients in total had de novo metastatic disease or disease recurrence. The median follow-up was 46 and 16 months for nccRCC and scRCC, respectively. The median overall survival for nccRCC with metastatic disease was 34 months (range, 14 months to not reached). Seventy percent of these patients received systemic therapy. By contrast, the median overall survival for scRCC with metastatic disease was 10 months (range, 1.6-89 months). Less than one-half of the patients with scRCC received systemic therapy in our cohort, with only 34% receiving no more than 1 line of treatment.

CONCLUSIONS

Our data confirm the rapid and aggressive course of scRCC, highlighting the need for more effective therapeutic strategies in this rare patient population.

Sarcomatoid Renal Cell Carcinoma: Population-Based Study of 879 Patients

BACKGROUND

Sarcomatoid renal cell carcinoma (sRCC) constitutes a rare and aggressive subtype of renal cell carcinoma. We aimed to investigate its clinicopathologic characteristics and outcomes at a national level.

PATIENTS AND METHODS

We accessed the National Cancer Institute's Surveillance, Epidemiology, and End Results database (2010-2015) and extracted data on patients with sRCC. We estimated median, 1-, 3-, and 5-year disease-specific survival (DSS) probabilities after generation of Kaplan-Meier curves and used multivariable regression to evaluate variables associated with nephrectomy and DSS.

RESULTS

A total of 879 patients with sRCC were identified; 60.9% patients had stage IV disease at diagnosis, and the median tumor size was 8.3 cm (interquartile range, 5.5-12 cm). The 5-year DSS were 77.7%, 67.8%, 35.4%, and 3.5% for patients with stage I, II, III, and IV disease at diagnosis, respectively; median DSS was 9 months (interquartile range, 4-42 months) for the entire cohort. Older age (hazard ratio [HR] = 1.01; 95% confidence interval [CI], 1.00-1.02), higher tumor stage (stage III vs. I: HR = 3.81; 95% CI, 2.18-6.67; stage IV vs. I: HR = 9.89; 95% CI, 5.80-16.98), and performance of nephrectomy (HR = 0.53; 95% CI, 0.43-0.66) were found to independently affect DSS.

CONCLUSION

In the largest sRCC cohort to date, we found that most patients present with metastatic disease, and the prognosis for this disease remains extremely poor. Nephrectomy should be considered in all patients with acceptable surgical risk, including cytoreductive nephrectomy in carefully selected patients with metastatic disease.

Epidemiology, biology and treatment of sarcomatoid RCC: current state of the art

Long recognized to confer an extremely poor prognosis, sarcomatoid dedifferentiation of renal cell carcinoma (sRCC) is a tumor phenotype that is finally beginning to be better understood on the molecular and genetic levels. With an overall incidence that ranges from 1 to 32% depending on associated RCC subtype, the survival of sarcomatoid RCC patients rarely exceeds 2 years. The main reasons for its poor outcome include its aggressive biology, its tendency to present at an advanced or metastatic stage at the time of diagnosis, its high rate of tumor recurrence after nephrectomy, and its limited response to systemic therapies. Molecular pathology studies suggest that sarcomatoid dedifferentiation originates from a focal epithelial-mesenchymal transition (EMT) arising in the carcinomatous component of the tumor. It is hoped that the growing understanding of the molecular biology of sRCC will soon make it possible to adapt treatments based on the identification of actionable tumor alterations. The deliberate inclusion of these patients in the multicenter clinical trials of immune, targeted and combination therapies is a necessary next step in pioneering future treatment strategies.

Phase 2 Trial of Capecitabine, Gemcitabine, and Bevacizumab in Sarcomatoid Renal-Cell Carcinoma

BACKGROUND

Patients with sarcomatoid renal-cell carcinomas (sRCC) have poor outcomes and limited treatment options. Preclinical and clinical data suggest susceptibility to cytotoxic agents and vascular endothelial growth factor-targeted therapies. We designed a phase 2 trial to evaluate the efficacy and safety of capecitabine, gemcitabine, and bevacizumab in sRCC.

PATIENTS AND METHODS

Patients with metastatic or unresectable sRCC were eligible for inclusion. Patients received oral capecitabine 800 mg/m2 twice daily on days 1 to 21 of a 28-day cycle, intravenous gemcitabine 900 mg/m2 on days 1 and 15, and intravenous bevacizumab 10 mg/kg on days 1 and 15. Primary end points were progression-free survival and time to treatment failure (TTF). Secondary end points were safety, objective response rate, and overall survival.

RESULTS

Thirty-four patients were enrolled onto the trial. One patient was excluded from survival analysis and 4 from response analysis as a result of missing data. Median progression-free survival was 5.5 months (95% confidence interval [CI], 3.4-7.7), median TTF was 4.2 months (95% CI, 2.4-6.0), and median overall survival was 12 months (95% CI, 10.6-13.4). Objective response rate was 20% (5 partial responses, 1 complete response), and disease control rate was 73%. Thirty-one (91%) of the 34 patients discontinued treatment. The most common reason for treatment discontinuation was progressive disease, which occurred in 24 patients (71%). The most common grade 3 toxicity was rash (including hand-foot syndrome) in 24% patients.

CONCLUSION

The combination of capecitabine, gemcitabine, and bevacizumab is an option for patients with sRCC; however, response rates are low. Novel therapies are needed to improve outcomes in patients with sRCC.