Chemotherapy for non-clear-cell renal cell carcinoma

Advances in non-clear cell renal cell carcinoma management: From heterogeneous biology to treatment options

Non-clear cell renal cell carcinoma (nccRCC) makes up nearly one quarter of all RCC subtypes, commonly impacts younger patients, and is often metastatic at presentation. Compared to clear-cell RCC (ccRCC), nccRCC typically has a worse prognosis in the metastatic setting, with overall survival durations that are ~10 months shorter. The nccRCC consists of a wide range of different histological subtypes, the majority of which are composed of papillary, chromophobe, renal medullary carcinoma, translocation RCC, collecting duct carcinoma and unclassified RCC. Most clinical trials have either excluded or only included small numbers of patients with nccRCC; owing to the lack of prospective studies focusing on this population, data on response rates and survival outcomes are lacking. NccRCC treatment is a nascent field with various therapeutic modalities and combinations under investigation, often based on data extrapolated from therapeutic studies in ccRCC. We herein review the use and outcomes of cytotoxic chemotherapy, various combination modalities of tyrosine kinase inhibitors and immune checkpoint inhibitors, and targeted agents. We discuss active ongoing clinical trials for patients with nccRCC and future directions in the treatment of this rare disease. Historically, treatment for nccRCC has been adopted from the standard of care for patients with ccRCC, although these treatments are less effective in the nccRCC population. As we begin to understand the underlying biology of these tumors, clinical trials have been able to slowly accrue and include more patients with various subtypes of nccRCC. There remains much room for improvement in this area of need, but there is hope on the horizon.

MYC activation cooperates with Vhl and Ink4a/Arf loss to induce clear cell renal cell carcinoma

Renal carcinoma is a common and aggressive malignancy whose histopathogenesis is incompletely understood and that is largely resistant to cytotoxic chemotherapy. We present two mouse models of kidney cancer that recapitulate the genomic alterations found in human papillary (pRCC) and clear cell RCC (ccRCC), the most common RCC subtypes. MYC activation results in highly penetrant pRCC tumours (MYC), while MYC activation, when combined with Vhl and Cdkn2a (Ink4a/Arf) deletion (VIM), produce kidney tumours that approximate human ccRCC. RNAseq of the mouse tumours demonstrate that MYC tumours resemble Type 2 pRCC, which are known to harbour MYC activation. Furthermore, VIM tumours more closely simulate human ccRCC. Based on their high penetrance, short latency, and histologic fidelity, these models of papillary and clear cell RCC should be significant contributions to the field of kidney cancer research.

Renal cell carcinoma (RCC) is a common and aggressive malignancy. Here, the authors generate two mouse models of the most common RCC subtypes: the human papillary RCC through MYC activation and clear cell RCC through MYC activation combined with Vhl and Cdkn2a deletion.

Sorafenib after combination therapy with gemcitabine plus doxorubicine in patients with sarcomatoid renal cell carcinoma: a prospective evaluation

BACKGROUND

Sarcomatoid renal cell cancer (RCC) is a distinct histological variant of RCC that is associated with rapid progression and a poor prognosis. The optimal treatment for patients with sarcomatoid RCC remains to be defined. Gemcitabine plus doxorubicine (GD) has shown some efficacy, however durability of response is limited. We carried out a prospective, open-label study to investigate the efficacy and safety of sorafenib in patients after GD failure in sarcomatoid RCC.

METHODS

Fifteen patients with pure sarcomatoid RCC and objective progressive disease were treated with GD (gemcitabine 1500 mg/m², doxorubicine 50 mg/m² administered by weekly intravenous infusion) until progression of disease. Subsequently 9 patients were switched to sorafenib (400 mg twice daily). Tumor response was measured by physical examination and computerized tomography scans and evaluated according to Response Evaluation Criteria in Solid Tumors criteria.

RESULTS

Median time to progression (TTP) under GD was 6.6 months (range 0.8 - 8 months). During GD treatment there were no remissions and 6 patients died from progressive disease. Median TTP for the 9 patients switched to sorafenib was 10.9 months (range 0.6 - 25.5 months). During sorafenib therapy one patient had a partial remission lasting for 3 months and 4 patients experienced stable disease with a duration of 3 to 9 months. Four patients immediately progressed on sorafenib treatment but had a slower dynamic of tumor progression than under GD. Dosing in both treatment phases was generally well tolerated with manageable toxicities and no requirement for dose reduction.

CONCLUSIONS

Chemotherapy with GD was ineffective in our patients with pure sarcomatoid RCC. Subsequent anti-angiogenic treatment using the multi-tyrosine kinase inhibitor sorafenib resulted in additional progression-free survival in 5 of 9 patients. Further evaluation of targeted anti-angiogenic agents for the treatment of sarcomatoid RCC is warranted.

Targeted therapy in renal cancer

Renal cell cancer (RCC) has an increasing incidence internationally and is a disease for which there have been limited therapeutic options until recently. The last decade has seen a vastly improved understanding of the biological and clinical factors that predict the outcome of this disease. We now understand some of the different molecular underpinnings of renal clear cell carcinoma by mutation or silencing of the von Hippel Lindau (VHL) gene and subsequent deregulated proliferation and angiogenesis. Survival in advanced disease is predicted by factors (performance status, anemia, hypercalcemia, and serum lactate dehydrogenase, time from diagnosis to recurrence) incorporated into the Memorial Sloan Kettering Cancer Center (MSKCC) criteria (also referred to as 'Motzer' criteria). These criteria allow classification of patients with RCC into good, intermediate and poor risk categories with median overall survivals of 22 months, 12 months and 5.4 months, respectively. Predicated upon these advances, six new targeted drugs (sorafenib, sunitinib, temsirolimus, everolimus, bevacizumab and pazopanib) have been tested in well-designed phase III trials, selected or stratified for MSKCC risk criteria, with positive results. All of these new drugs act at least in part through vascular endothelial growth factor (VEGF) mediated pathways with other potential therapeutic impact on platelet-derived growth factor (PDGF), raf kinase and mammalian target of rapamycin (mTOR) pathways. Importantly, data from each of these trials show a consistent doubling of progression-free survival (PFS) over prior standard of care treatments. In addition, sorafenib, sunitinib and temsirolimus, have demonstrated significant overall survival (OS) benefits as well; further follow-up is required to determine whether the disease control exhibited by everolimus and pazopanib will translate into a survival advantage. These drugs are generally well tolerated, as demonstrated by quality-of-life improvement in clinical trials, and result in clinical benefit for in excess of 70% of patients treated. They have challenged the traditional outcomes of clinical trial design by achieving their benefits with relatively few radiographic responses, but high rates of disease stability. The unique side-effect profile coupled with the chronicity of therapy requires increased vigilance to maximize exposure to the drugs while maintaining quality of life and minimizing toxicity. This review focuses on the background, clinical development and practical use of these new drugs in RCC.

Improving outcomes in patients with advanced renal cell carcinoma

The emergence of targeted therapies for advanced renal cell carcinoma has been a dramatic turning point in improving outcomes for the majority of patients with this disease. In study populations comprising primarily good- and intermediate-risk patients with clear cell renal cell carcinoma and prior nephrectomy, prolonged progression-free survival was demonstrated for three angiogenesis-targeted agents: sunitinib (compared with interferon [IFN]), bevacizumab plus IFN (vs IFN alone) and sorafenib (vs placebo in cytokine-refractory patients). As a first-line treatment for patients with multiple poor-risk factors, temsirolimus, which inhibits mTOR, has improved not only progression-free survival compared with IFN but, more importantly, overall survival. Further studies are needed to determine whether combinations and/or sequencing of these targeted agents can further improve outcomes.