An Update on the Treatment of Papillary Renal Cell Carcinoma

Papillary renal cell carcinoma (pRCC) is the second-most common subtype of kidney cancer following clear cell renal cell carcinoma (ccRCC), representing 15% of kidney cancers. Despite advances in therapy, including combination strategies with targeted therapies and immune checkpoint inhibitors, progress has lagged behind that of ccRCC. This is in part due to the heterogenous nature of the various subtypes of pRCC. More recently, investigators have turned efforts towards histology and biology-based trials. In this review, we outline some of the distinct biological characteristics of pRCC and discuss the most impactful clinical trials to date. Finally, we look ahead to several highly anticipated ongoing trials in pRCC.

Papillary renal cell carcinoma: what is missing in research? A case report and a review of literature

The incidence of renal cell carcinomas in adults ranges has been increasing over the past decades in both men and women. Once the incidence was 2.9%, now is reported to have increased to 3%–5% with male predominance according to the most recent reports of cancer statistics. The disease typically describes a group of different histopathological subtypes; the most common is clear cell carcinoma which accounts for 70%–80% of the diagnosed cases, while papillary renal cell carcinoma and chromophobe types represent 20% and 5%, respectively. In 1996, the renal cell carcinomas Heidelberg classification was introduced by Delahunt et al. It divides renal cell tumors into benign and malignant parenchymal neoplasms, excluding Wilm’s tumor and secondary metastases and limiting each subcategory to the most commonly documented genetic abnormalities, if applicable. In this report, we discuss a case of metastatic type I papillary renal cell carcinoma treated with the anti-vascular endothelial growth factor receptor sunitinib and showing marked long-term clinical response. Through this case, we highlight the importance of re-classifying papillary renal cell carcinoma subtypes to prioritize the clinical management of these cases.

Hypertension and Circulating Cytokines and Angiogenic Factors in Patients With Advanced Non-Clear Cell Renal Cell Carcinoma Treated With Sunitinib: Results From a Phase II Trial

BACKGROUND

We evaluated the significance of hypertension developing during vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitor (VEGFR-TKI) treatment and a group of cytokines and angiogenic factors (CAFs) in advanced non-clear cell renal cell carcinoma (nccRCC) patients treated with sunitinib in a phase II study.

MATERIALS AND METHODS

Using multiplex assays, we analyzed the levels of 38 CAFs in plasma at baseline and after 4 weeks of sunitinib therapy. Sunitinib benefit was defined as a partial response or stable disease using the Response Evaluation Criteria in Solid Tumors lasting ≥4 months. Cox proportional hazards regression models were used to assess the associations among hypertension, CAFs, and progression-free (PFS) and overall survival (OS).

RESULTS

Fifty-seven patients were evaluable; 53 had baseline CAF levels available. The median PFS and OS were 2.9 months (95% confidence interval [CI], 1.4-5.5) and 16.8 months (95% CI, 10.7-27.4), respectively. Sunitinib benefit was observed in 21 patients (37%). However, 33 patients (60%) developed hypertension during treatment, although no association was found with survival or response. Elevated baseline soluble tumor necrosis factor (TNF) receptor I, interleukin-8, growth-regulated oncogene, transforming growth factor-α, and VEGFR-2 levels were associated with an increased risk of death on multivariate analysis.

CONCLUSION

We found no association between the development of hypertension and survival or sunitinib benefit in advanced nccRCC. TNF and angiogenic/immunomodulatory mediators were identified for evaluation as markers of prognosis and VEGFR-TKI benefit in future studies.

Multicenter phase II study of sunitinib in patients with non-clear cell renal cell carcinoma

BACKGROUND

Retrospective and molecular biologic data suggest that sunitinib may be effective in patients with non-clear cell renal cell carcinoma (nccRCC).

PATIENTS AND METHODS

Eligibility criteria included advanced nccRCC except for collecting duct carcinoma and sarcomatoid carcinoma without identifiable renal cell carcinoma subtypes. Patients were treated with 50 mg/day oral sunitinib for 4 weeks, followed by 2 weeks of rest. The primary end point was overall response rate (RR).

RESULTS

Thirty-one eligible patients were enrolled. Twenty-four patients (77%) had prior nephrectomy. By Memorial Sloan-Kettering Cancer Center criteria, 8 patients (26%) had poor risk and 14 (45%) had intermediate risk. Twenty-two patients had papillary renal cell carcinoma (RCC), and three had chromophobe RCC. Eleven patients had partial response with a RR of 36% (95% confidence interval (CI) 19% to 52%) and an additional 17 patients (55%) had stable disease. Median duration of response was 12.7 months (95% CI 6.3-19.1 months), and median progression-free survival was 6.4 months (95% CI 4.2-8.6 months). At a median follow-up duration of 18.7 months (95% CI 13.7-23.7 months), 13 patients (42%) had died, resulting in an estimated median survival of 25.6 months (95% CI 8.4-42.9 months). Toxicity profiles were commensurate with prior reports.

CONCLUSIONS

Sunitinib has promising activity in patients with nccRCC (NCT01219751).

Efficacy of sunitinib and sorafenib in metastatic papillary and chromophobe renal cell carcinoma

PURPOSE

Sunitinib and sorafenib are novel tyrosine kinase inhibitors (TKIs) that have shown significant clinical activity in metastatic clear cell renal cell carcinoma (RCC). The activity of sunitinib and sorafenib in non-clear cell histologies has not been evaluated.

PATIENTS AND METHODS

Clinical features at study entry and treatment outcomes were evaluated in patients with metastatic papillary RCC (PRCC) and chromophobe RCC (ChRCC) who received either sunitinib or sorafenib as their initial TKI treatment in five US and French institutions. Response rate and survival were documented. Fisher's exact test was used for categoric variables, and the Kaplan-Meier method was used to estimate survival.

RESULTS

Fifty-three patients were included. The number of patients with papillary and chromophobe histologies was 41 (77%) and 12 (23%), respectively. Response rate, progression-free survival (PFS) time, and overall survival time for the entire cohort were 10%, 8.6 months, and 19.6 months, respectively. Three (25%) of 12 ChRCC patients achieved a response (two patients treated with sorafenib and one treated with sunitinib), and PFS was 10.6 months. Two (4.8%) of 41 PRCC patients achieved a response (both patients were treated with sunitinib). PFS for the whole cohort was 7.6 months. Sunitinib-treated PRCC patients had a PFS of 11.9 months compared with 5.1 months for sorafenib-treated patients (P < .001).

CONCLUSION

Patients with PRCC and ChRCC may have prolonged PFS from sunitinib and sorafenib, although clinical responses remain overall low in PRCC. Additional prospective trials with these agents in non-clear cell RCC will further clarify their use in the future.

Protein expression profiles in renal cell carcinoma: staging, prognosis, and patient selection for clinical trials

Attempts to predict survival in patients with renal cell carcinoma (RCC) have traditionally relied on standard clinical variables, such as tumor-node-metastasis stage, histologic grade, and performance status. An accurate method for predicting patient survival is useful for patient counseling, planning follow-up, and selecting patients most likely to benefit from novel and established therapies. Furthermore, an improved prognostic system will allow for more accurate comparisons of clinical trials based on varying inclusion criteria. A large number of potential prognostic markers have recently been identified from methods based on gene arrays, which screen for differential expression of thousands of genes. The accepted method of clinical validation of novel markers is on formalin-fixed and paraffin-embedded specimens using immunohistochemistry. The development of tissue microarrays as a high-throughput technique has allowed for thousands of different cores of pathologic tissue to be assessed simultaneously in a timely and cost-efficient manner. This technology has enabled the analysis of protein expression profiles on specimens to determine their potential clinical significance and role in RCC biology. This article reviews the protein expression profiles in RCC and their association with pathobiology, prognosis, and response to treatment as well as their role in serving as potential molecular targets for therapy of RCC.

Update on the epidemiology and biology of renal cortical neoplasms

A new era is developing in the understanding of the diagnosis, classification, and management of renal-cell carcinoma (RCC). Historically, RCC has been divided into subtypes on the basis of the histopathologic findings alone. Now, genetic alterations, nuclear characteristics, and clinical criteria are routinely incorporated into the classification. The greater use of axial imaging that began in the 1980s dramatically increased the incidence of RCC, but there has not been a decrease in the percentage of cases that are metastatic. Nevertheless, many incidental lesions prove to be benign, so there is renewed enthusiasm for biopsy before treatment is selected. Genetic conditions associated with RCC, such as Von Hippel Lindau and Birt-Hogg-Dube syndromes, along with genetic analyses of tumors, have provided considerable insight into the pathogenesis of these lesions. Renal-cell carcinoma is resistant to chemotherapy, and high-dose interleukin-2 is the only regimen currently approved by the Food and Drug Administration for the treatment of advanced RCC. Stem cell transplantation is an evolving therapy. The vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), platelet-derived growth factor (PDGF), and transforming growth factor-alpha pathways are promising targets for medical therapy of RCC. Bevacizumab, a monoclonal antibody that acts as a competitive blocker of the VEGF receptor; sorafenib, an oral well-tolerated tyrosine kinase inhibitor that blocks the intracellular second-messenger system associated with the VEGF receptor; sunitinib, a multitarget inhibitor of kinases associated with the VEGF and PDGF receptors; temsirolimus (CCI-779), a kinase blocker that inhibits the mammalian target of rapamycin pathway; and erlotinib, an inhibitor of the tyrosine kinases associated with the EGF receptor, have shown promise. Combinations of the above therapies and cytokines also are being investigated, as there may be synergistic effects.

Evolving principles of surgical management and prognostic factors for outcome in renal cell carcinoma

The generally accepted principles for the surgical management of renal cell carcinoma (RCC) were first described more than 30 years ago. Since then, much has changed in the understanding of the basic biology and genetics of kidney cancer. Improvements in cross-sectional imaging has allowed for more accurate preoperative clinical staging of renal tumors, and the necessity of completing all the components of the radical nephrectomy have been questioned. Surgical techniques have also evolved, and technology has advanced to make possible new methods of managing renal tumors. The TNM staging system is currently the most extensively used system to provide prognostic information for RCC. However, data published in the last few years has led to significant controversies as to whether further revisions are needed and whether improvements can be made with the introduction of new, more accurate and predictive prognostic factors. Furthermore, the recent discovery of molecular tumor markers are expected to revolutionize the staging of RCC and lead to the development of new therapies based on molecular targeting. This review will examine the evolving principles in the surgical management of RCC as well as provide an update on current staging modalities and prognostic factors.

Kidney cancer therapy: new perspectives and avenues

Immunotherapy with interleukin-2 and interferon-alpha has been the only viable option in metastatic renal cell cancer for almost two decades. In the last several years, significant advances in the understanding of the underlying biological and molecular mechanisms of renal cell carcinoma, particularly the role of tumour angiogenesis, have led to the identification of rational therapeutic targets and permitted the design of molecularly targeted therapeutics. At present, new compounds targeting specific signalling pathways are available and have successfully passed clinical testing. The use of small molecules, such as multitargeted tyrosine kinase inhibitors, the mTOR inhibitors and monoclonal antibodies, is dramatically changing the existing concepts of systemic treatment for metastatic kidney cancer.

Adjuvant treatment for renal cell carcinoma

Despite significant advances in the diagnosis, staging and treatment of patients with renal cell carcinoma, recurrence rates following surgical resection of locally aggressive tumours remain high. In an effort to delay disease progression and improve survival, the concept of adjuvant therapy has been proposed. Optimal adjuvant therapy for surgically resected renal cell carcinoma remains to be defined and the evaluation of adjuvant therapies will require properly controlled and adequately powered randomised trials. Promising preliminary results have been seen with active immunotherapies and agents that target critical signalling pathways, and there are several Phase III trials of these novel treatment options that are underway. In addition, classification of patients into high- and low-risk subgroups on the basis of a prognosis profile will serve as a useful means to guide clinicians in improving the selection of patients who are likely to derive benefit from adjuvant therapy. This will lead to a future area of investigation, which will be the identification of patients within the target population that should respond to a given treatment. This review will discuss the role and current status of adjuvant therapies for renal cell carcinoma.