Researchers are still searching for an effective treatment or cure for renal cancer, cancer of the kidneys. Haas and colleagues published a new trial that suggests that a class of treatment that inhibits growth of the blood vessels that keep cancer tumors alive. In a small clinical trial, they found that this class of drug does not work on renal cancers in particular.
Cancer refers to a group of different diseases characterized by abnormal cell growth. In cancer, cells don’t die when they’re supposed to. Although benign tumors can occur, cancerous tumors can spread to other parts of the body. Cancer causes over 10% of deaths worldwide. Renal cancer, in particular, is one of the top ten cancers among both men and women. Renal refers to the kidneys — a pair of bean-shaped organs about the size of your fist. Their job is to filter the blood and create urine. Five-year survival rates for individuals with early stage renal cancers are high. However, survival rates are low for those with advanced renal cancer.
As with many cancers, scientists are searching for a cure for renal cancer. New research has focused on a class of drugs that slow or stop growth of the blood vessels that keep cancerous tumors alive. These are called adjuvant vascular endothelial growth factor tyrosine kinase inhibitors, or VEGF-TKIs. A recent clinical trial in patients showed that a new therapy based on these inhibitors did not affect cancer progression. However, a smaller trial in patients with advanced cancer showed more promise. These patients apparently had improvements to cancer-free five-year survival rates.
Haas and colleagues recently published a paper in JAMA Oncology re-evaluating cancer-free survival rates in these advanced stage renal cancer patients, as well as the effects of VEGF-TKI dosage on survival. Their sample consisted of 1069 patients with advanced stage kidney cancer. Patients were randomly assigned to receive either a low dose of 50mg or placebo, taken orally on 28 days of every 42-day cycle, or a high dose of 400mg or placebo, taken twice daily. This clinical trial lasted 54 weeks overall and was double-blind. This means that neither the patients nor the doctors administering the treatment knew which treatment they were receiving. Some dose adjustments were made over the course of the study to decrease side effects.
Neither patients on the low dose or high dose fared better than patients on placebo. All groups had cancer-free survival rates of about 50% over the course of five years. This means that the drugs had no effect on the cancer, regardless of dosage. About two-thirds of patients experienced adverse side-effects. These results are consistent with those of other clinical trials.
The sample size for this study was small and may not be enough to differentiate the effects of the drug on specific subsets of patients. VEGF-TKIs may be useful for some individuals in some cases. However, they do not appear to be useful in slowing or stopping renal cancer in general.
Written By: C.I. Villamil