Stereotactic Ablative Radiation Therapy May Improve Outcomes for Recurrent Oligometastatic Cancer
Stereotactic ablative radiation therapy (SABR) may help to improve outcomes for recurrent oligometastatic cancer and is accompanied by minimal acute and late grade 3 toxicity, according to a multicenter, phase 2 trial.
“Oligometastatic disease has emerged as a potentially curable state in the spectrum of cancer progression. Aggressive local therapy such as SABR may improve oncologic outcomes,” the researchers wrote. To investigate the feasibility of SABR in these patients, investigators prospectively recruited 147 patients with oligometastatic cancer to the study between 2011 and 2017. These patients’ most common primary tumors were lung, colorectal adenocarcinoma, and head and neck. Lesion size and location determined SABR dose and fractionation.
After SABR was complete, patients were followed up within 6 weeks and every 3 months thereafter. At baseline and at each follow up, patients took a Functional Assessment of Cancer Therapy-General questionnaire to evaluate patient-reported quality of life (PR-QoL).
After a median of 41.3 months, the median overall survival was 42.3 months, with 5-year overall survival at 43%. Five-year local progression-free survival was 74%, distant progression-free survival was 17%, and acute grade 2+ and 3+ toxicity were 7.5% and 2.0%, respectively. Lastly, both late grade 2+ and 3+ toxicity were 1.4%.
The researchers noted that quality of life had no significant changes at 6 weeks, 3 months, and 9 months following treatment, though patients had statistically significant improvement in PR-QoL at 6 and 12 months.
“This multicenter prospective phase 2 study demonstrates that SABR for recurrent oligometastatic cancer is a feasible and tolerable treatment option with minimal acute and late grade 3 toxicity. Additionally, PR-QoL was not adversely affected,” the researchers concluded.
Sutera P, Clump DA, Kalash R, et al. Initial Results of a Multicenter Phase 2 Trial of Stereotactic Ablative Radiation Therapy for Oligometastatic Cancer. Int J Radiat Oncol Biol Phys. 2019 Jan 1;103(1):116-122.