Up to 15 percent of kidney cancer patients are diagnosed with tumor thrombus, a locally advanced form of the disease where the tumor extends into the renal vein progressing sometimes into the inferior vena cava (IVC), the body’s largest vein. Once in the IVC, the tumor has open passage to the heart.
Surgery is the standard of care, but operating on such tumors is challenging, particularly if they have reached the heart. One third of the patients experience complications and mortality can be as high as 15 percent.
“These extensions can be problematic. They can block drainage of the blood into the heart causing backup, liver congestion, and swelling,” says Vitaly Margulis, M.D., a urological surgeon with expertise in this type of surgery.
In 2015 , Kidney Cancer Program (KCP) investigators developed a novel approach involving stereotactic ablative radiotherapy (SAbR). By targeting the tumor thrombus with high doses of radiation delivered from multiple angles, researchers were able to show that tumor thrombus could be controlled.
While the approach is still being evaluated in a clinical trial at UTSW (NCT02141919), an unmet medical need has led to its early adoption by institutions across the world.
A recently published report chronicles initial findings from the global experience. Fifteen patients with a tumor thrombus reaching the IVC were treated with SAbR at six leading centers in the US, UK, Italy and Australia. In 50 percent of patients the tumor thrombus approximated or invaded into the heart. About half of the patients were poor candidates for surgery and in 20 percent the tumor came back after surgery.
SAbR controlled the tumor thrombus in over 80 percent of patients relieving them from symptoms including liver congestion, swelling, bleeding and pain. While medication therapy may have contributed to thrombus control, similar benefit was observed in a subset of patients that received only SAbR.
“We are delighted to see that our pioneering efforts are benefiting patients across the world,” said Raquibul Hannan, M.D., Ph.D., co-Leader of radiation oncology at the KCP.
“This is an example of the innovation and team approach that characterizes the KCP,” said Kidney Cancer Program Director James Brugarolas, M.D., Ph.D.
