Widely Used Kidney Cancer Drugs Fail to Stop Recurrence Post-Surgery

Two widely used drugs for the treatment of metastatic kidney cancer were found to be no more effective in preventing disease recurrence than a placebo, during a recent study.

Surgery is considered the best first treatment option for renal tumors, but surgery alone is not enough to prevent cancer recurrence. Adjuvant therapies are used in hopes of improving survival rates.

In the study, researchers at the Abramson Cancer Center enrolled 1943 patients from the United States and Canada who were administered 1 year of the kinase inhibitors sorafenib or sunitinib, or a placebo, after having undergone kidney tumor removal surgery.

The results of the study, published in the Lancet, showed there was no difference in the median years of disease free survival post-surgery. The data reflected 5.8 years for sunitinib, 6.1 years for sorafenib, and 6.6 years for placebo.

Although the data did not show the adjuvant therapy drugs were effective, it did give a definitive answer on the drug’s use to help prevent associated toxic effects and costs.

“The current standard of care for these patients is close observation,” said researcher Naomi B. Haas MD. “Unfortunately, we found that the use of sunitinib or sorafenib in this setting did not reduce the incidence of recurrence as compared to placebo. Fortunately, the use of these drugs in this setting did not appear to make the outcome of patients receiving them any worse.”

The findings were similar to adjuvant trials for tumors in other cancers, such as breast cancer and metastatic colorectal cancers, where the benefits of bevacizumab on metastatic disease were not seen.

Currently, there are other adjuvant trials being conducted studying different lengths of therapy with sunitinib, sorafenib, and different kinase inhibitors, but these results are not yet available.

“It is important to support these trials so we learn how to better treat kidney cancer in the adjuvant setting," Haas said.

The beginning stages of the trial reported about one-third of patients stopped treatment because of side effects like fatigue, hypertension, or intolerability to the medications.

Furthermore, patient blood and urine samples collected at the beginning of the study are currently undergoing analyses to help determine which patients could benefit from sunitinib and sorafenib.

“This will afford opportunities to uncover molecular clues and other information that could help explain why some patients had a recurrence of their cancer or a spreading elsewhere and others did not,” Haas said.

Future plans are in the works for a perioperative trial that uses an immune checkpoint inhibitor.