Sarcomatoid differentiation as a prognostic factor for immunotherapy in metastatic renal cell carcinoma

Prognostic factors for overall survival and intracranial progression in patients with renal cancer metastasis into the brain after neurosurgical treatment

Introduction. Treatment of patients with brain metastases is an important problem that should be considered in the framework of combination approach. Introduction of new techniques of drug therapy as well as radiotherapy and neurosurgical treatment allows to significantly increase patient survival. Effective drug therapy and local control of brain metastases are of utmost importance in prediction of overall survival and patient quality of life.

Aim. To investigate the prognostic factors for overall survival and intracranial progression (local recurrences, distant metastases) in patients with brain metastases of renal cancer after neurosurgical resection.

Materials and methods. Retrospective analysis of the treatment results of 114 patients with metastatic brain lesions due to renal cancer who underwent neurosurgical resection (NSR) at the N. N. Blokhin National medical Research Center of Oncology was performed. Clinical data of 102 (89.5 %) of 114 patients for whom data on survival was available were evaluated. Among them, 80 (78.4 %) of patients died, 22 (21.5 %) are under observation. Extracranial disease status at the time of NSR was known in 82 (71.9 %) patients: 45 (54.8 %) patients had extracranial metastases, and 37 (45.1 %) did not. Total resection of brain metastases with perifocal and perivascular zones was performed in 92 (90.1 %) patients; in other cases, fragmental lesion resection was performed.

Results. median overall survival after NSR was 13.8 months (95 % confidence interval 10.3–18.6). per study data, factors affecting overall survival of patients with brain metastases of renal cancer after neurosurgical resection were presence /  absence of extracranial metastases and patient’s functional status. Local recurrences in the postoperative cavity after NSR were observed in 24 (21 %) of 114 patients. median time of local recurrence was not achieved. Statistically significant factor of high risk of recurrence in the postoperative cavity was presence of lesions with maximal diameter ≥2 cm. Development of new (distant) metastases was observed in 31 (27.2 %) of 114 patients. median survival without distant metastases in patients with brain metastases after NSR was not achieved. frequencies of distant metastases at 6, 12 and 24 months were 15.5; 24.1 and 35.8 % respectively. per multifactor analysis, factors affecting development of distant metastases in the brain after NSR are multiple metastatic brain lesions and presence of extracranial metastases.

Conclusion. Neurosurgical resection in patients with cerebral metastases of renal cancer in the total group leads to median overall survival of 13.8 months. predictors of better overall survival are absence of extracranial metastases and high functional status.

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.

Durable Remission with Immunotherapy in a Patient with Sarcomatoid Renal Cell Carcinoma

Sarcomatoid differentiation is a rare and aggressive histologic subtype with poor prognosis, seen in several malignancies. In sarcomatoid renal cell carcinoma (RCC), the degree of sarcomatoid differentiation and the stage at presentation determines the prognosis. Despite resection, chemotherapy and targeted therapy response is modest, with relapse usually occurring within a few months. We present a case of a gentleman with sarcomatoid RCC managed with pembrolizumab, who has had no evidence of recurrence for over 4 years since the last dose of immunotherapy. RCCs with sarcomatoid differentiation have a high presence of programmed cell death protein 1 and programmed cell death ligand 1 in T cells and tumor cells, respectively, making immunotherapy an attractive option in this setting. Clinical trials are ongoing to further define the benefit of immunotherapy in sarcomatoid RCC.

Prognostic Significance of Sarcomatoid Differentiation in Patients With Metastatic Renal Cell Carcinoma: A Systematic Review and Meta-Analysis

Background

To date, the prognostic value of sarcomatoid differentiation in patients having metastatic renal cell carcinoma (mRCC) remains inconclusive. A systematic review and meta-analysis were conducted.

Materials and Methods

Relevant literatures were obtained from PubMed, Embase, and Cochrane Library published prior to May, 2020. All patients were diagnosed with mRCC and treated with surgery, cytokine therapy, targeted therapy, and immunotherapy. Sarcomatoid differentiation in the pathological specimens was identified. Each endpoint [overall survival (OS), progression-free survival (PFS), and cancer-specific survival (CSS)] was assessed using a multivariable adjusted hazard ratio (HR) and 95% confidence interval (CI).

Results

Fifteen observational studies having 5,828 patients with mRCC were included. The merged results showed that patients presenting sarcomatoid differentiation had a significantly inferior OS (HR: 2.26, 95% CI: 1.82-2.81; P < 0.001), PFS (HR: 2.28, 95% CI: 1.63-3.19; P < 0.001), and CSS (HR: 2.27, 95% CI: 1.51-3.40; P < 0.001) compared to those without sarcomatoid differentiation. Subgroup analysis based on publication year, patient population, country, number of cases, and NOS score did not change the direction of results. A significant publication bias was identified for OS, but no publication bias was identified for PFS. Moreover, sensitivity analysis also verified the robustness of the results.

Conclusion

This study suggested that sarcomatoid differentiation was correlated to unfavorable clinical outcomes in mRCC and may be a poor prognostic factor incorporating to prognostic models for mRCC patients.

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.

Sarcomatoid Renal Cell Carcinoma With Unusual Metastasis to the Small Intestine Manifesting as Perforated Appendicitis

BACKGROUND

Sarcomatoid renal cell carcinoma is a rare form of dedifferentiated carcinoma with a high metastatic rate and adverse prognosis. Common sites of metastasis include lymph nodes, lung, liver and bone. We report a case of sarcomatoid renal cell carcinoma with unusual metastasis to the small intestine in a 65-year-old female with a history of clear-cell renal cell carcinoma with focal sarcomatoid transformation.

CASE REPORT

The patient presented to the Emergency Department with worsening abdominal pain. Imaging showed perforated acute appendicitis, however, diagnostic laparoscopy found no evidence of appendicitis, but a small punctate perforation in the small intestine. Gross examination of the small intestine showed a 2 cm tan-white lobular firm lesion at the perforation site involving the full thickness of the wall. Histological examination revealed a high-grade spindle-cell neoplasm with hyperchromatic and pleomorphic nuclei, frequent mitotic figures, and necrosis. Immunohistochemically, the tumor cells were positive for CD10 and carbonic anhydrase 9, but negative for pan-cytokeratin, epithelial membrane antigen, paired box gene 8, renal cell carcinoma, desmin, smooth-muscle actin, c-KIT, discovered on gastrointestinal stromal tumor protein 1, CD34, and S100. Molecular studies showed that the tumor cells were microsatellite stable but harbored mutations in polybromo-1, telomerase reverse transcriptase, and von Hippel-Lindau genes, supporting renal cell carcinoma in nature. The patient received radiation therapy but unfortunately died after one month due to rapid disease progression.

CONCLUSION

This was a rare and challenging case of sarcomatoid renal cell carcinoma metastasis to the small intestine with loss of some renal cell carcinoma markers, reinforcing the aggressive nature of this entity and the importance of correlating findings with the prior history for reaching correct diagnosis.

Analysis of the factors influencing the survival time of patients with sarcomatoid renal cell carcinoma

The aim of the present study was to identify the factors influencing the survival time of patients with sarcomatoid renal cell carcinoma (SRCC). Between January 2000 and September 2017, a total of 21 patients were enrolled, all of whom were diagnosed with SRCC. In total, eight prognostic factors were analyzed using the Kaplan-Meier estimator, a log-rank test and Cox's proportional hazards model. The log-rank test results revealed that there was a significant association between the proportion of sarcoma elements and survival time of patients with SRCC (P<0.05). In addition, there was a significant association between post-operative drug treatment and SRCC survival time (P<0.05). The results of the Kaplan-Meier estimate demonstrated that the survival curve of post-operative drug treatment was significantly greater compared with the survival curve of patients who did not undergo drug treatment (P<0.05). The survival curve of patients with a proportion of sarcoma elements <50% was significantly greater compared with the survival curve of patients with a proportion of sarcoma elements ≥50% (P<0.05). Furthermore, the Cox's proportional hazards model revealed that the mortality risk in post-operative patients without drug treatment was 5.822 times greater compared with that of patients with drug treatment (P<0.05). Mortality risk in patients with a proportion of sarcoma elements ≥50% was 4.682 times higher compared with that of patients with sarcoma elements <50% (P<0.05). Finally, post-operative drug therapy was revealed to be a protective factor which significantly affected the survival time of patients with SRCC [risk ratio (RR)=0.172], in addition to the proportion of sarcoma elements ≥50% (RR=4.682). In conclusion, drug therapy should be promoted upon patient diagnosis with SRCC and attention should be given to the proportion of sarcomatoid components.

Prognostic factors and survival in Japanese patients with brain metastasis from renal cell cancer

BACKGROUND

Patients with brain metastasis from renal cell carcinoma have poor outcomes despite recent advances in diagnosis and treatment. Moreover, factors affecting such poor outcomes are unclear. This study aimed to evaluate the prognostic factors associated with overall survival in renal cell carcinoma patients with brain metastasis.

METHODS

We retrospectively reviewed the data of 50 consecutive patients with brain metastasis from renal cell carcinoma at our institution between 1988 and 2017. The evaluated prognostic factors for overall survival included clinicopathological factors at diagnosis, treatment for brain metastasis, and the Graded Prognostic Assessment score of renal cell carcinoma. The associations between preoperative clinicopathological factors and overall survival were assessed using the log-rank test and Cox proportional hazards models for univariate and multivariate analyses, respectively.

RESULTS

Forty-five patients were included, among whom 39 died during follow-up. The median follow-up was 8.2 months. The median survival time was 8.2 months (95% confidence interval 5.5-13.7). A Graded Prognostic Assessment score ≤ 2 (hazard ratio 1.967; 95% confidence interval 1.024-3.892; P = 0.042), the presence of sarcomatoid components (hazard ratio 3.299; 95% confidence interval 1.424-7.193; P = 0.007), and no treatment for brain metastasis (hazard ratio 2.594; 95% confidence interval 1.033-5.858; P = 0.043) were independently associated with poor prognosis in the multivariate analysis.

CONCLUSIONS

Patients with renal cell carcinoma who develop brain metastasis have poor overall survival. The Graded Prognostic Assessment score, sarcomatoid components, and treatment for brain metastasis from renal cell carcinoma were independent factors associated with prognosis.

The prognostic value and clinicopathological features of sarcomatoid differentiation in patients with renal cell carcinoma: a systematic review and meta-analysis

Background and purpose

Numerous studies have demonstrated that sarcomatoid differentiation is linked to the risk of renal cell carcinoma (RCC). However, its actual clinicopathological impact remains inconclusive. Therefore, we undertook a meta-analysis to evaluate the pathologic and prognostic impacts of sarcomatoid differentiation in patients with RCC by assessing cancer-specific survival, overall survival, recurrence-free survival, progression-free survival, and cancer-specific mortality.

Materials and methods

In accordance with the preferred reporting items for systematic reviews and meta-analysis statement, relevant studies were collected systematically from PubMed, Embase, and Web of Science to identify relevant studies published prior to January 2018. The pooled effects (hazard ratios, odds ratios, and standard mean differences) and 95% confidence intervals were calculated to investigate the association of sarcomatoid differentiation with cancer prognosis and clinicopathological features.

Results

Thirty-five studies (N=11,261 patients [n=59-1,437 per study]) on RCC were included in this meta-analysis. Overall, the pooled analysis suggested that sarcomatoid differentiation was significantly associated with unfavorable cancer-specific survival (HR=1.46, 95% CI: 1.26-1.70, p<0.001), overall survival (HR=1.59, 95% CI: 1.42-1.78, p<0.001), progression-free survival (HR=1.61, 95% CI: 1.35-1.91, p<0.001), recurrence-free survival (HR=1.60, 95% CI: 1.29-1.99, p<0.001), and cancer-specific mortality (HR=2.36, 95% CI: 1.64-3.41, p<0.001) in patients with RCC. Moreover, sarcomatoid differentiation was closely correlated with TNM stage (III/IV vs I/II: OR=1.84, 95% CI: 1.12-3.03, p=0.017), Fuhrman grade (III/IV vs I/II: OR=8.37, 95% CI: 2.92-24.00, p<0.001), lymph node involvement (N1 vs N0: OR=1.88, 95% CI: 1.08-3.28, p=0.026), and pathological types (clear cell RCC-only vs mixed type: OR=0.48, 95% CI: 0.29-0.80, p=0.005), but was not related to gender (male vs female, OR=0.86, 95% CI: 0.58-1.28, p=0.464) and average age (SMD=-0.02, 95% CI: -0.20-0.17, p=0.868).

Conclusion

This study suggests that sarcomatoid differentiation in histopathology is associated with poor clinical outcome and advanced clinicopathological features in RCC and could serve as a poor prognostic factor for RCC patients.

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.

Sarcomatoid renal cell carcinoma: Biology and treatment advances

Sarcomatoid transformation in renal cell carcinoma, so called sacromatoid RCC (sRCC), is associated with an aggressive behavior and a poor prognosis. Current therapeutic approaches are largely ineffective. Recent studies looking into the genomic and molecular characterization of sRCCs have provided insights into the biology and pathogenesis of this entity. These advances in molecular signatures may help development of effective treatment strategies. We herein present a review of recent developments in the pathology, biology, and treatment modalities in sRCC.

The Role of Metastasectomy in Patients with Renal Cell Carcinoma with Sarcomatoid Dedifferentiation: A Matched Controlled Analysis

PURPOSE

Management of metastatic renal cell carcinoma with sarcomatoid dedifferentiation remains a therapeutic challenge with no standard treatment strategies. We evaluated whether metastasectomy has any survival benefit in patients with metastatic sarcomatoid dedifferentiation treated with radical nephrectomy.

MATERIALS AND METHODS

From an institutional database of 273 patients with sarcomatoid dedifferentiation treated with nephrectomy we matched 80 with synchronous and asynchronous metastases for age, ECOG (Eastern Cooperative Oncology Group) performance status, histology and lymph node status. Matched pairs were then retained only if patients who did not undergo metastasectomy were alive at metastasectomy comparable to matched surgical patients to decrease the bias of survival outcomes. Overall survival from nephrectomy was studied using univariable and multivariable proportional hazards regression.

RESULTS

Median overall survival was 8.3 (95% CI 6.5-10.5) and 18.5 months (95% CI 11.5-42.9) in patients with synchronous and asynchronous metastases, respectively. Overall survival in patients who underwent metastasectomy for synchronous metastasis compared to nonsurgical patients was 8.4 and 8.0 months (p = 0.35), respectively. Similarly, overall survival in patients with asynchronous metastases treated with metastasectomy compared to the nonsurgical group was 36.2 and 13.7 months, respectively (p = 0.29). On multivariable analysis positive lymph nodes at nephrectomy were associated with an increased risk of death in the synchronous and asynchronous patient subgroups (HR 2.1, 95% CI 1.1-4.0, p = 0.03 and HR 3.3, 95% CI 1.2-9.2, p = 0.02, respectively).

CONCLUSIONS

In the current study there was no clear evidence of benefit in patients with sarcomatoid dedifferentiation who underwent metastasectomy after nephrectomy. Particularly, the group of patients with pathological lymph node positive disease at nephrectomy had considerably worse survival.

Wild-type VHL Clear Cell Renal Cell Carcinomas Are a Distinct Clinical and Histologic Entity: A 10-Year Follow-up

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is an aggressive tumor with 50% risk of metastases at initial diagnosis or at follow-up. An inactivation of the tumor-suppressor gene von Hippel-Lindau (VHL) is present in >70% of sporadic cases by two of three different mechanisms: locus deletion, gene mutation, or promoter hypermethylation.

OBJECTIVE

To correlate the complete status of the VHL gene with clinical and pathologic criteria.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively included 98 patients with ccRCC who underwent surgery between 2002 and 2005. VHL gene deletions (71 of 98; 72.4%), mutations (68 of 98; 69.4%), and promoter hypermethylations (13 of 98; 13.3%) were screened by gene copy analysis, gene sequencing, and methylation-specific multiplex ligation-dependent probe amplification, respectively.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Relationships between VHL subgroups and the studied criteria were analyzed using chi-square and Student t tests. Survival was analyzed with the log-rank test and Kaplan-Meier curves.

RESULTS AND LIMITATIONS

Compared with ccRCCs with two events (66.3%), tumors with no or one genetic event (33.6%) were associated with a higher nuclear grade IV (p=0.02), metastases (p=0.04), sarcomatoid component (p=0.01), dense lymphocyte infiltrate (p=0.013), and vascular endothelial growth factor overexpression (>30%) (p=0.003), which was also an independent factor after multivariate analysis. Furthermore, wild-type VHL tumors (no inactivating event, 11.2%) were associated with nodal involvement (p=0.019), and patients with this type of tumor had a specific survival of 33 mo compared with patients with ccRCCs having one or two VHL inactivating events (107 mo; p=0.016). The retrospective design with small number of wild-type tumors was a limitation of this work.

CONCLUSIONS

This long-term study (10-yr clinical follow-up) confirms that ccRCCs with wild-type VHL are highly aggressive tumors that need to be formally identified.

PATIENT SUMMARY

Among activated VHL tumors, the wild-type subgroup defines an aggressive phenotype with worse survival rates, suggesting that these tumors must be more thoroughly screened.

Using percentage of sarcomatoid differentiation as a prognostic factor in renal cell carcinoma

BACKGROUND

The objective of this study was to determine if the percentage of sarcomatoid differentiation (%Sarc) in renal cell carcinoma (RCC) can be used for prognostic risk stratification, because sarcomatoid RCC (sRCC) is an aggressive variant of kidney cancer.

PATIENTS AND METHODS

We performed a retrospective analysis of patients who underwent surgery for RCC at our institution between 1999 and 2012. Pathology slides for all sRCC cases were reexamined by a single pathologist and %Sarc was calculated. %Sarc was analyzed as a continuous variable and as a categorical variable at cut points of 5%, 10%, and 25%. Potential prognostic factors associated with overall survival (OS) were determined using the Cox regression model. OS curves were generated using Kaplan-Meier methods and survival differences compared using the log-rank test.

RESULTS

One thousand three hundred seven consecutive cases of RCC were identified, of which 59 patients had sRCC (4.5%). As a continuous variable %Sarc was inversely associated with OS (P = .023). Predictors of survival on multivariable analysis included pathologic (p) T status, tumor size, clinical (c) M status and %Sarc at the 25% level. OS was most dependent on the presence of metastatic disease (4 months vs. 21.2 months; P = .001). In cM0 patients with locally advanced (≥ pT3) tumors, OS was significantly diminished in patients with > 25 %Sarc (P = .045). However, %Sarc did not influence OS in patients with cM1 disease.

CONCLUSION

Patients with sRCC have a poor overall outcome as evidenced by high rates of recurrence and death, indicating the need for more effective systemic therapies. In nonmetastatic patients, the incorporation of %Sarc in predictive nomograms might further improve risk stratification.

Systemic therapy for non-clear cell renal cell carcinomas: a systematic review and meta-analysis

CONTEXT

Clinical data supporting the use of targeted agents for the treatment of metastatic renal cell carcinoma (RCC) are based predominantly on patients with clear cell histology. Little is known about the efficacy of these drugs in non-clear cell variants.

OBJECTIVE

To evaluate the efficacy of different clear cell RCC (ccRCC)-approved targeted agents among patients with non-ccRCC compared with ccRCC.

EVIDENCE ACQUISITION

We conducted a systematic review of electronic databases to identify publications evaluating the outcomes of patients with non-ccRCC treated with targeted agents approved for treatment of ccRCC. Patients with sarcomatoid variant RCC were excluded from the main analysis but were evaluated as an independent cohort. End points of interest were response rate, median progression-free survival (PFS), and median overall survival (OS). Where possible, data were pooled in a meta-analysis. For studies of unselected patients with RCC, the outcomes of patients with non-ccRCC histology were compared with ccRCC. In exploratory analyses, outcomes of non-ccRCC with nonapproved agents were assessed.

EVIDENCE SYNTHESIS

A total of 49 studies comprising 7771 patients were included in the analysis. Of these, 1244 patients (16.0%) had non-ccRCC, 6300 (83.1%) had ccRCC, and 227 (2.9%) had sarcomatoid tumours. The overall response rate for non-ccRCC with targeted agents was 10.5%. In studies directly comparing non-ccRCC and ccRCC, there were significantly lower response rates for non-ccRCC (odds ratio for response: 0.52; 95% confidence interval, 0.40-0.68; p<0.001). For non-ccRCC treated with targeted agents, median PFS and OS were 7.4 and 13.4 mo, respectively; for patients with ccRCC, these were 10.5 mo and 15.7 mo, respectively (p value for difference<0.001 for both parameters).

CONCLUSIONS

Patients with non-clear cell renal cell carcinoma (non-ccRCC) have significantly lower response rates and poorer median progression-free survival and overall survival than those with ccRCC. The optimal treatment of patients with non-ccRCC remains unclear and warrants further study.

PATIENT SUMMARY

Systemic treatments for patients with renal cell carcinoma (RCC) tend to be significantly less effective for non-clear cell RCC, with lower response rates and worse progression-free survival and overall survival when compared with clear cell RCC. Optimal therapy remains unclear and warrants further study.

Understanding pathologic variants of renal cell carcinoma: distilling therapeutic opportunities from biologic complexity

CONTEXT

Once believed to represent a uniform malignant phenotype, renal cell carcinoma (RCC) is now viewed as a diverse group of cancers that arise from the nephron.

OBJECTIVE

To review the pathologic characteristics, clinical behavior, molecular biology, and systemic therapy options of recognized RCC histologic subtypes.

EVIDENCE ACQUISITION

A systematic review of English-language articles was performed using the Medline and Web of Science databases. Manuscripts were selected with consensus of the coauthors and evaluated using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) criteria.

EVIDENCE SYNTHESIS

The major findings of the evaluated manuscripts are discussed with an emphasis on the description of the pathologic features, clinical behavior, prognosis, and therapeutic strategies.

CONCLUSIONS

Classification schemes for kidney cancer have undergone dramatic changes over the past two decades. Improvements in these classification schemes are important, as pathologic variants differ not only in disease biology, but also in clinical behavior, prognosis, and response to systemic therapy. In the era of genomic medicine, further refinements in characterization of RCC subtypes will be critical to the progress of this burgeoning clinical space.

PATIENT SUMMARY

Kidney cancer can be subdivided into related but different cancers that arise from the kidney's tubules. In this article we review current classifications for kidney cancer, discuss their characteristics, and provide an overview of each subtype's clinical behavior and treatment. We stress that each subtype harbors unique biology and thus responds differently to available treatment strategies.

Renal cell carcinoma with rhabdoid and sarcomatoid features presented as a metastatic thigh mass with an unusual immunohistochemical profile

Renal cell carcinoma (RCC) may metastasize anywhere in the body and sometimes the primary tumor is missing and necessitates extensive investigations to detect. In this report, we describe a case of RCC metastasizing to the thigh in a 70 year old male with a highly pleomorphic morphology suggesting a high grade sarcoma that showed unequivocal positivity for desmin directing the diagnosis for pleomorphic rhabdomyosarcoma. After completion of 33 cycles of radiotherapy, the patient developed large intraabdominal mass that showed conventional areas of RCC with immunoreactivity for CD10, CK, EMA, carbonic anhydrase IX and vimentin. The tumor cells in other areas resembled that of thigh mass which raised suspicions whether the two masses represented the same tumor or not. Surprisingly, the tumor cells of thigh mass showed diffuse positivity for CD10 and focal expression for CK, EMA and carbonic anhydrase IX. Extensive investigations failed to detect any primary renal lesions. The present case demonstrated that RCC can metastasize to virtually any body site and can have significant morphologic overlap with other non-renal neoplasms. Absence of primary origin of RCC according to radiological and operative data should not hinder the diagnosis of metastatic RCC. RCC with sarcomatoid and rhabdoid features carries aggressive behavior manifested by great metastatic potential and short survival time.

Sarcomatoid renal cell carcinoma with rhabdoid features

Sarcomatoid renal cell carcinoma (SRCC) with rhabdoid features is a rare tumor with aggressive behavior and poor prognosis. We report a case of a 71-year-old man with a large left-sided renal mass. Nephrectomy specimen revealed clear cell carcinoma with sarcomatoid and rhabdoid tumor cells. The rhabdoid cells were immunoreactive for mesenchymal markers such as vimentin, epithelial markers such as cytokeratin, and epithelial membrane antigen. These cells were also positive for p53 and had a high proliferation index. The rhabdoid component also demonstrated the loss of immunostaining for integrase interactor 1 (INI1), which stained the other components of the tumor. Only a few cases are available in the published reports documenting rhabdoid cells in SRCC. None of these cases were studied by INI1 immunostain.

Sunitinib in combination with gemcitabine for advanced solid tumours: a phase I dose-finding study

BACKGROUND

This phase I, dose-finding study determined the maximum tolerated dose (MTD), safety, and pharmacokinetics of sunitinib plus gemcitabine in patients with advanced solid tumours.

METHODS

Two schedules with sunitinib (25-50 mg per day) and IV gemcitabine (750-1250 mg m(-2)) in escalating doses were studied. First, patients received sunitinib on a 4-weeks-on-2-weeks-off schedule (Schedule 4/2) plus gemcitabine on days 1, 8, 22, and 29. Second, patients received sunitinib on a 2-weeks-on-1-week-off schedule (Schedule 2/1) plus gemcitabine on days 1 and 8. The primary endpoint was determination of MTD and tolerability.

RESULTS

Forty-four patients received the combination (Schedule 4/2, n=8; Schedule 2/1, n=36). With no dose-limiting toxicities (DLTs) at maximum dose levels on Schedule 2/1, MTD was not reached. Grade 4 treatment-related AEs and laboratory abnormalities included cerebrovascular accident, hypertension, and pulmonary embolism (n=1 each), and neutropenia (n=3), thrombocytopenia and increased uric acid (both n=2), and lymphopenia (n=1). There were no clinically significant drug-drug interactions. Antitumor activity occurred across dose levels and tumour types. In poor-risk and/or high-grade renal cell carcinoma patients (n=12), 5 had partial responses and 7 stable disease ≥ 6 weeks.

CONCLUSION

Sunitinib plus gemcitabine on Schedule 2/1 with growth factor support was well tolerated and safely administered at maximum doses of each drug, without significant drug-drug interactions.

Sarcomatoid renal cell carcinoma: a comprehensive review of the biology and current treatment strategies

Recent advancements in the molecular characterization of renal cell carcinoma altered the classification system and now kidney cancer is divided into several distinct histologic subtypes. Although once a separate histologic category, sarcomatoid renal cell carcinoma is no longer considered a separate tumor type because it can occur with all histologic subtypes. Limited research on tumors with sarcomatoid change has led to minimal progress in the understanding and treatment of these tumors. Because the sarcomatoid variant of renal cell carcinoma can account for approximately one in six cases of advanced kidney cancer, we hope to familiarize clinicians with these tumors by describing the historic background, histologic features, molecular characterization, diagnosis, prognosis, treatment strategies, and active clinical trials of this aggressive type of tumor.

Sarcomatoid-variant renal cell carcinoma: treatment outcome and survival in advanced disease

OBJECTIVES

Sarcomatoid variant is a spindle cell phenotype of renal cell carcinoma (RCC), which is associated with a poor prognosis. We reviewed outcomes of systemic therapy for metastatic, sarcomatoid-variant RCC.

METHODS

Clinical features, treatment outcome, and survival were evaluated in 63 patients with sarcomatoid-variant metastatic RCC (47 clear cell, 16 nonclear cell). Initial systemic treatment included antiangiogenesis-targeted therapy (n=34), cytokines (n=20), and chemotherapy (n=9).

RESULTS

Five of 63 patients (8%) achieved an objective response to the first systemic treatment: 1 (5%) to cytokine and 4 (12%) to sunitinib-targeted therapy. Median progression-free survival for 63 patients was 3 months (95% confidence interval), and median overall survival was 10 months (95% confidence interval). The median progression-free survival for patients treated with sunitinib versus all others was 4.4 months versus 2 months (P=0.03), and 3 months for patients with clear-cell histology versus 1.6 months for nonclear-cell histology (P=0.004).

CONCLUSIONS

Metastatic sarcomatoid-variant RCC was associated with a poor response to systemic therapy. Sunitinib treatment resulted in a modest response rate, but studies to characterize the underlying tumor biology of sarcomatoid-variant RCC, to assess outcome to targeted agents, and to develop novel treatment strategies are warranted.

Relevance of periostin splice variants in renal cell carcinoma

The extracellular matrix N-glycoprotein periostin is thought to enhance tumor invasion. In this study, the expression patterns of periostin and its splice isoforms were investigated in renal cell carcinoma (RCC). Periostin mRNA expression patterns were characterized in 30 fresh-frozen RCCs in normal fetal and adult renal tissues by both isoform-specific and nonspecific RT-PCR and by gene expression array analysis. Its protein expression was analyzed by immunohistochemistry, using tissue microarrays with tissue from 1007 RCC patients. Periostin mRNA in RCC was increased, as observed in both RT-PCR and gene microarray analyses, with significantly higher expression in the clear cell than in the papillary subtype. Four of eight periostin isoforms, identified in fetal kidney by direct sequencing, have not been described to date. Three isoforms could be detected in both RCC and matched non-neoplastic tissue, and one of them was expressed more frequently in RCC. Periostin protein was detected in both mesenchymal cells of the tumor stroma and epithelial tumor cells. Greater amounts of periostin in tumor epithelia correlated with the presence of sarcomatoid differentiation, higher tumor stage, lymph node metastases, and poor overall survival in the clear cell subtype. In conclusion, periostin expression in tumor epithelia may contribute to sarcomatoid differentiation and more aggressive behavior of RCC. The presence of a tumor-associated periostin isoform suggests splice-specific regulation in RCC tissue.

Factors affecting outcome in renal cell carcinoma

PURPOSE OF REVIEW

To review the latest status on prognostic factors in renal cell carcinoma (RCC).

RECENT FINDINGS

Many predictive and prognostic factors can help differentiate between favorable and unfavorable RCC phenotypes. There currently exist several clinical and/or pathological, and biological factors, which have been exclusively tested and used in predictive and prognostic models. Nonetheless, the search for highly informative and reliable factors of disease characteristics and progression continues.

CONCLUSION

Over the last decade, an increase occurred in the number of models that can predict the treated natural history of RCC. Many of these novel models and previously developed models are tested in a head-to-head fashion, with the intent of identifying the most accurate and valuable tools for clinical practice. Novel prognostic factors and more up-to-date models are urgently needed for patients with metastatic RCC, especially in the era of targeted therapies. This should represent the focus of contemporary prognostic modeling in RCC.

Percutaneous biopsy of primary tumor in metastatic renal cell carcinoma to predict high risk pathological features: comparison with nephrectomy assessment

PURPOSE

As treatment options evolve for metastatic renal cell carcinoma, there is a need for predictive information to help guide therapy. We assessed the accuracy of percutaneous primary tumor biopsy for metastatic renal cell carcinoma by comparing biopsy findings to final nephrectomy pathology in patients undergoing cytoreductive nephrectomy.

MATERIALS AND METHODS

Using an institutional database we reviewed the records of patients who underwent percutaneous primary tumor biopsy before cytoreductive nephrectomy. In patients who underwent biopsy elsewhere pathology findings were re-reviewed at our institution. Differences in accuracy based on biopsy technique, imaging modality and biopsy period were determined by chi-square analysis.

RESULTS

We identified 166 patients who underwent percutaneous biopsy of the primary tumor before cytoreductive nephrectomy between 1991 and 2007, and had data available for review. Median pathological tumor size was 9.1 cm (range 3 to 32). Median time from biopsy to surgery was 46 days (range 6 to 717). Of 104 patients in whom biopsy was assigned a Fuhrman nuclear grade 33 (31.7%) had the same grade in the nephrectomy specimen, including 74 of 109 (67.9%) when considering only high or low grade. Grade change by more than 2 points was seen in 18 of 104 patients (17.3%). Sarcomatoid features were present in 34 of 166 nephrectomy specimens (20.5%) but only 4 (11.8%) were identified preoperatively.

CONCLUSIONS

In patients with metastatic renal cell carcinoma percutaneous renal biopsy has poor accuracy to assess Fuhrman nuclear grade or sarcomatoid features. Physicians should use caution when using biopsy data to guide therapy.

Histologic evaluation of metastases in renal cell carcinoma with sarcomatoid transformation and its implications for systemic therapy

BACKGROUND

Sarcomatoid features in renal cell carcinoma may represent an aggressive subclone arising from the primary tumor. The patterns of metastases for these tumors were evaluated to determine if sarcomatoid features were retained at metastasis and whether the percentage of sarcomatoid features in the primary tumor influenced spread.

METHODS

All patients with sarcomatoid features found at nephrectomy with synchronous or metachronous resection of metastases were evaluated. The histology, grade, and percentage of sarcomatoid features in the primary and metastatic site were recorded. The association between percentage of sarcomatoid features, grade, histology, and pattern of metastases was evaluated.

RESULTS

Thirty-two patients were identified with sarcomatoid features and resected metastases. Fifty-two metastatic sites were evaluated. A single histologic appearance (sarcomatoid or carcinomatoid) was present in 50 of 52 sites (96%). Thirty sites (58%) demonstrated only a sarcomatoid pattern, whereas 20 (38%) contained only a carcinoma pattern. Histology and carcinoma grade did not influence metastatic pattern; however, greater percentage of sarcomatoid features was associated with the presence of distant sarcomatoid histology. A cutoff of 30% sarcomatoid features in the primary tumor was useful in predicting systemic sarcomatoid histology.

CONCLUSIONS

Sarcomatoid elements are frequently observed in the metastases of primary tumors with sarcomatoid features, and these metastases generally contain a solitary pattern supporting the subclone hypothesis. However, both components can metastasize in the same patient. The percentage of sarcomatoid features influences the pattern of spread, and patients with >30% sarcomatoid features in the primary tumor frequently have distant sarcomatoid histology. This cutpoint may be helpful for inclusion criteria for future clinical trials.

Metastatic Sarcomatoid Renal Cell Carcinoma Treated With Vascular Endothelial Growth Factor–Targeted Therapy

Purpose

Metastatic renal cell carcinoma (mRCC) with sarcomatoid differentiation is an aggressive disease that is associated with poor outcomes to chemotherapy or immunotherapy. The utility of vascular endothelial growth factor (VEGF)–targeted therapy in patients with this disease is unknown.

Patients and Methods

Patients who had mRCC with sarcomatoid features in the primary tumor and who were treated with VEGF-targeted therapy were retrospectively identified. Pathology slides were reviewed to determine the percentage of sarcomatoid differentiation. Objective response rate, percentage of tumor burden shrinkage, progression-free survival (PFS), and overall survival (OS) were determined.

Results

Forty-three patients who had sarcomatoid mRCC were identified. The median percentage of sarcomatoid features was 14% (range, 3% to 90%). Patients were treated with either sunitinib (49%), sorafenib (28%), bevacizumab (19%), or sunitinib plus bevacizumab (5%). Partial responses were observed in eight patients (19%); 21 patients (49%) had stable disease; and 14 patients (33%) had progressive disease as their best response. Partial responses were limited to patients who had underlying clear-cell histology and less than 20% sarcomatoid elements. Median tumor shrinkage was −2% (range, −85% to 127%), and 53% achieved some degree of tumor shrinkage on therapy. Median PFS and OS were estimated to be 5.3 months and 11.8 months, respectively.

Conclusion

Patients who have mRCC and sarcomatoid differentiation can demonstrate objective responses and tumor shrinkage to VEGF-targeted therapy. Patients who have clear-cell histology and a lower percentage of sarcomatoid differentiation may have better outcomes with VEGF-targeted therapy.

Identification of copy number alterations and its association with pathological features in clear cell and papillary RCC

We report and characterize the copy number alterations (CNAs) in 35 clear cell and 12 papillary renal cell carcinomas (RCC) using Affymetrix 100K SNP arrays. Novel gain and loss regions are identified in both subtypes. In addition, statistically significant CNA are detected and associated with the pathological features: VHL mutation status, tumor grades, and sarcomatoid component in clear cell RCC and in types 1 and 2 of papillary RCC. Florescence in situ hybridization confirmed the copy number gain in the transforming growth factor, beta-induced gene (TGFBI), which is a possible oncogene for clear cell RCC.