Building upon “pioneering work” at University of Texas Southwestern (UTSW) Medical Center (Dallas, USA), investigators recently reported the results of a clinical trial exploring the role of stereotactic ablative radiation therapy (SAbR) for patients with a handful of metastases, or so-called oligometastatic disease.
As per a UTSW press release, the study represents the first clinical trial for patients with untreated oligometastatic kidney cancer.
“There has never been a clinical trial for these patients. It is unclear whether these patients should be treated with medication, surgery, or another approach. This represents an unmet medical need,” said Raquibul Hannan (UTSW, Dallas, USA), lead author of the study along with Robert Timmerman and James Brugarolas (both UTSW).
As per the release, kidney cancer encompasses a wide spectrum and can present with extensive metastases, or just a handful. However, today, all patients are treated the same way—with medication. Metastatic kidney cancer is typically treated with immunotherapy agents or targeted drugs, which are toxic and diminish quality of life. For most patients, the disease ultimately progresses, necessitating a change in treatment, until patients exhaust their options. When metastatic, most patients eventually succumb to the disease, and the quality of their remaining lifespan is negatively impacted by the cancer drugs.
The phase 2 clinical trial tested SAbR, a treatment that delivers potent, narrow beams of radiation to tumours, in 23 kidney cancer patients with oligometastases (up to five metastases) at UTSW and the affiliated county hospital, Parkland Health. Patients received SAbR to metastatic tumours at the outset and while the disease remained oligometastatic. Overall, 57 metastases were treated.
The primary goal was to control the metastatic cancer in at least 60% of patients at one year. The study was successful, with more than 90% of patients demonstrating disease control at one year without systemic therapy.
“It appears that most patients will be free of systemic therapy for at least two years,” said Hannan.
None of the patients experienced serious side-effects either, the release notes, and periodic questionnaires showed no negative impact on quality of life. A large, phase 3 randomised clinical trial evaluating SAbR for oligometastatic kidney cancer has now been approved by the National Cancer Institute and will also be led by Hannan.
“If successful, this phase 3 trial will establish, for the first time, a standard of care for patients with oligometastatic kidney cancer,” added Brugarolas. “The hope is that the treatment will help patients by delaying progression while preserving their quality of life.”