Treating metastatic kidney cancer with stereotactic ablative radiation therapy achieves more than 90% control of local tumours, and offers the possibility of safely delaying systemic therapy, found a University of Texas Southwestern Medical Centre study.
"This study shows that stereotactic radiation provides a good non-invasive alternative to conventional treatment such as surgery, and that it effectively controls the disease," said Dr Raquibul Hannan, assistant professor of radiation oncology and co-leader of the kidney cancer programme of the Harold C Simmons Comprehensive Cancer Centre and senior author of the study. "It may also offer an alternative to patients who are not candidates for surgery. Often due to the number and location of the metastases and sometimes due to other conditions, patients are not candidates for surgery."
The standard of care for metastatic renal cell carcinoma is systemic therapy, which can be associated with significant side effects like tiredness, fatigue, high blood pressure, and rash. These side effects can be significant and debilitating. According to Hannan, the new study shows that patients with metastatic kidney cancer can be treated with stereotactic radiation therapy with the goal of being cured, or to delay systemic therapy allowing patients to enjoy a better quality of life without the side effects of the drugs.
"This study, which represents, possibly, the largest experience reported in the literature, may also help medical oncologists, since stereotactic radiation could also be used for patients who have limited sites of disease progression while receiving systemic therapy," said Dr James Brugarolas, leader of the kidney cancer programme. It can also assist surgeons, since when kidney cancer has spread, the tumours are often not amenable to surgical removal.
The research was conducted in the kidney cancer programme, one of two programmes in the country to be recognised with an $11m Specialised Programme of Research Excellence (SPORE) from the National Cancer Institute. As part of the SPORE, researchers are improving the ways in which radiation is given, by evaluating combinations with drugs and identifying those tumours that are most likely to respond.
In particular, investigators are evaluating combinations with immunotherapy, iSABR – immunotherapy and stereotatic ablative radiation therapy.
Nearly 400,000 Americans are now living with a diagnosis of kidney cancer and more than 60,000 people are expected to be diagnosed with kidney cancer this year, according to the National Cancer Institute.
Five-year survival rate averages run from 81% for stage 1, when cancer is contained in the kidney, to about 53% for stage 3, when it has spread beyond the kidney, and just 8% for stage 4, when the cancer spreads to more distant parts of the body or other organs. However, 5-year survival rates at the UT Southwestern's kidney cancer programme are double national benchmarks.
Abstract
Purpose: Renal cell carcinoma is refractory to conventional radiation therapy but responds to higher doses per fraction. However, the dosimetric data and clinical factors affecting local control (LC) are largely unknown. We aimed to evaluate the safety and efficacy of stereotactic ablative radiation therapy (SAbR) for extracranial renal cell carcinoma metastases.
Methods and Materials: We reviewed 175 metastatic lesions from 84 patients treated with SAbR between 2005 and 2015. LC and toxicity after SAbR were assessed with Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 and Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. Predictors of local failure were analyzed with χ2, Kaplan-Meier, and log-rank tests.
Results: In most cases (74%), SAbR was delivered with total doses of 40 to 60 Gy, 30 to 54 Gy, and 20 to 40 Gy in 5 fractions, 3 fractions, and a single fraction, respectively. The median biologically effective dose (BED) using the universal survival model was 134.5 Gy. The 1-year LC rate after SAbR was 91.2% (95% confidence interval, 84.9%-95.0%; median follow-up, 16.7 months). Local failures were associated with prior radiation therapy (hazard ratio [HR], 10.49; P<.0001), palliative-intent radiation therapy (HR, 4.63; P=.0189), spinal location (HR, 5.36; P=.0041), previous systemic therapy status (0-1 vs >1; HR, 3.52; P=.0217), and BED Conclusions: SAbR demonstrated excellent LC of metastatic renal cell carcinoma with a favorable safety profile when an adequate dose and coverage were applied. Multimodality treatment with surgery should be considered for reirradiation or vertebral metastasis. A higher radiation dose may be required in patients who received previous systemic therapies.
Authors
Chiachien Jake Wang, Alana Christie, Mu-Han Lin, Matthew Jung, Derek Weix, Lorel Huelsmann, Kristin Kuhn, Jeffrey Meyer, Neil Desai, DW Nathan Kim, Ivan Pedrosa, Vitaly Margulis, Jeffrey Cadeddu, Arthur Sagalowsky, Jeffrey Gahan, Aaron Laine, Xian-Jin Xie, Hak Choy, James Brugarolas, Robert Timmerman, Raquibul Hannan
[link url="https://www.sciencedaily.com/releases/2017/05/170502113808.htm"]University of Texas Southwestern Medical Centre material[/link]
[link url="http://www.redjournal.org/article/S0360-3016(17)30044-5/fulltext"]International Journal of Radiation Oncology abstract[/link]