Stereotactic Radiotherapy for Oligoprogression in Metastatic Renal Cell Cancer Patients Receiving Tyrosine Kinase Inhibitor Therapy: A Phase 2 Prospective Multicenter Study.

Despite the paucity of prospective evidence, stereotactic radiotherapy (SRT) is increasingly being considered in the setting of oligoprogression to delay the need to change systemic therapy.

To determine the local control (LC), progression-free survival (PFS), cumulative incidence of changing systemic therapy, and overall survival (OS) after SRT to oligoprogressive metastatic renal cell carcinoma (mRCC) lesions in patients who are on tyrosine kinase inhibitor (TKI) therapy.

A prospective multicenter study was performed to evaluate the use of SRT in oligoprogressive mRCC patients. Patients with mRCC who had previous stability or response after ≥3 mo of TKI therapy were eligible if they developed progression of five of fewer metastases. Thirty-seven patients with 57 oligoprogressive tumors were enrolled.

Oligoprogressive tumors were treated with SRT, and the same TKI therapy was continued afterward.

Competing risk analyses and the Kaplan-Meir methodology were used to report the outcomes of interest.

The median duration of TKI therapy prior to study entry was 18.6 mo; 1-yr LC of the irradiated tumors was 93% (95% confidence interval [CI] 71-98%). The median PFS after SRT was 9.3 mo (95% CI 7.5-15.7 mo). The cumulative incidence of changing systemic therapy was 47% (95% CI 32-68%) at 1 yr, with a median time to change in systemic therapy of 12.6 mo (95% CI 9.6-17.4 mo). One-year OS was 92% (95% CI 82-100%). There were no grade 3-5 SRT-related toxicities.

LC of irradiated oligoprogressive mRCC tumors was high, and the need to change systemic therapy was delayed for a median of >1 yr.

The use of stereotactic radiotherapy in metastatic kidney cancer patients, who develop growth of a few tumors while on oral targeted therapy, can significantly delay the need to change to the next line of drug therapy.

European urology. 2021 Aug 13 [Epub ahead of print]

Patrick Cheung, Samir Patel, Scott A North, Arjun Sahgal, William Chu, Hany Soliman, Belal Ahmad, Eric Winquist, Tamim Niazi, Francois Patenaude, Gerald Lim, Daniel Yick Chin Heng, Arbind Dubey, Piotr Czaykowski, Rebecca K S Wong, Anand Swaminath, Scott C Morgan, Rupi Mangat, Sareh Keshavarzi, Georg A Bjarnason

Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, University of Toronto, Toronto, ON, Canada., Division of Radiation Oncology, Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, AB, Canada., Division of Medical Oncology, Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, AB, Canada., Division of Radiation Oncology, Department of Oncology, London Health Sciences Centre, Western University, London, ON, Canada., Division of Medical Oncology, Department of Oncology, London Health Sciences Centre, Western University, London, ON, Canada., Division of Radiation Oncology, Department of Oncology, Jewish General Hospital, McGill University, Montreal, QC, Canada., Department of Oncology, Jewish General Hospital, McGill University, Montreal, QC, Canada., Division of Radiation Oncology, Department of Oncology, Tom Baker Cancer Centre, University of Calgary, Calgary, AB, Canada., Division of Medical Oncology, Department of Oncology, Tom Baker Cancer Centre, University of Calgary, Calgary, AB, Canada., Department of Radiation Oncology, CancerCare Manitoba, University of Manitoba, Winnipeg, MB, Canada., Department of Medical Oncology and Hematology, CancerCare Manitoba, University of Manitoba, Winnipeg, MB, Canada., Radiation Medicine Program, Department of Radiation Oncology, Princess Margaret Cancer Centre, University of Toronto, Toronto, ON, Canada., Department of Oncology, Juravinski Cancer Centre, McMaster University, Hamilton, ON, Canada., Division of Radiation Oncology, Department of Radiology, The Ottawa Hospital Cancer Centre, University of Ottawa, Ottawa, ON, Canada., Ozmosis Research Inc., Toronto, ON, Canada., Department of Biostatistics, Princess Margaret Cancer Centre, Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada., Division of Medical Oncology, Department of Medicine, Sunnybrook Odette Cancer Centre, University of Toronto, Toronto, ON, Canada. Electronic address: .