Treatment of metastatic renal cell carcinoma.

PURPOSE: To review the treatment of metastatic renal cell carcinoma (RCC), including the use of new targeted therapies.
METHODS: A search of MEDLINE (1966 to August 2008) and American Society of Clinical Oncology Meeting abstracts (2005 to May 2008) was preformed using the search terms bevacizumab, everolimus, interferon-alfa (IFN-alpha), interleukin-2 (IL-2), sorafenib, sunitinib, temsirolimus, and RCC. Articles most pertinent to the treatment of metastatic RCC are reviewed.
RESULTS: The treatment of metastatic RCC has undergone a paradigm shift over the past 5 years from biologic response modifiers to new targeted therapies. Historically, response rates for the biological response modifiers, aldesleukin (IL-2), and IFN-alpha were approximately 15%. Recently, three targeted agents, sorafenib, sunitinib, and temsirolimus have been approved for the treatment of RCC. Additionally, bevacizumab has been investigated and shown to increase progression free survival in RCC. IL-2 remains the only agent to induce complete, durable remissions; however, many patients are not eligible for this therapy. Newer agents (sorafenib, sunitinib, and temsirolimus) have shown to be superior to IFN-alpha or placebo and bevacizumab combined with IFN-alpha has shown activity when compared to IFN-alpha alone. Unlike IL-2, the greatest benefit obtained with targeted therapies is in achieving stable disease (SD). Despite their benefit, targeted therapies have never been compared with each other in clinical trials and choosing the most appropriate agent remains challenging. To date, the optimal sequence or combination of treatments has not been defined; however, everolimus has recently demonstrated activity in patients progressing on targeted therapy.
CONCLUSIONS: IL-2 remains the most active regimen in inducing complete responses; however, its use is accompanied by substantial morbidity and is limited to those with a good performance status. Targeted therapies are also efficacious in the treatment of RCC, with the major benefit being induction of SD. Future research will better define the sequencing of therapies, as well as, explore the activity of novel combination regimens.