This impressive review summarises cutting edge evidence for treating metastatic kidney cancer. Kidney cancer accounts for 2% of all cancers, one third present as metastatic or locally advanced and unresectable, and 25% of patients who have a kidney operation for what was thought to be local disease, recur. The key results are:
- Treatment naïve good risk patients – in good prognosis metastatic kidney cancer (clear cell pathology) sunitinib, a tyrosine kinase inhibitor that blocks VEGF and PDGF receptors implicated in new vessel growth, provides longer progression free survival of 11 months versus IFN alpha 5 months. Thee is no overall survival benefit however
- Treatment naïve poor risk – Temsirolimus an mTOR inhibitor is the choice with a better progression free survival of 2.5 months (5.5 v 3.1) and overall survival benefit 3 months (10.9 v 7.3) when given alone or combined with interferon alpha. Patients need to have minimum 3 of 6 poor risk factors (LDH >1.5 upper limit, anemia, calcium > 2.5 mmol/l, recurrence time
- Previously failed cytokine treatment – use sorafenib a VEGF inhibitor gives a progression free survival benefit of 5.5 v 2.8 months and overall survival benefit 17.8 v 14.3 months
- Combination therapy is not used and under investigation due to high toxicity
- Two randomized trials show the benefit of resecting the primary kidney cancer in metastatic disease especially beneficial in good risk patients so that primary tumor removal is the standard of care in metastatic renal cancer patients, who will then be given cytokine treatment
- In certain patients with metastases after the primary tumor had been removed, these metastatic lesions should be surgically removed giving a 5 year survival rate of 35-60%. Goo prognostic factors are: time to recurrence > 1 year, lung metastases better than brain, a single metastatic site rather than multiple and age <60.