Clinical and molecular markers of long‐term survival after oligometastasis‐directed stereotactic body radiotherapy (SBRT)

Abstract

BACKGROUND:The selection of patients for oligometastasis-directed ablative therapy remains a challenge. The authors report on clinical and molecular predictors of survival from a stereotactic body radiotherapy (SBRT) dose-escalation trial for oligometastases. METHODS: Patients who had from 1 to 5 metastases, a life expectancy of >3 months, and a Karnofsky performance status of >60 received escalating SBRT doses to all known cancer sites. Time to progression, progression-free survival, and overall survival (OS) were calculated at the completion of SBRT, and clinical predictors of OS were modeled. Primary tumor microRNA expression was analyzed to identify molecular predictors of OS. RESULTS: Sixty-one evaluable patients were enrolled from 2004 to 2009. The median follow-up was 2.3 years for all patients (range, 0.2-9.3 years) and 6.8 years for survivors (range, 2.0-9.3 years). The median, 2-year, and 5-year estimated OS were 2.4 years, 57%, and 32%, respectively. The rate of progression after SBRT was associated with an increased risk of death (hazard ratio [HR], 1.44; 95% confidence interval [CI], 1.24-1.82). The time from initial cancer diagnosis to metastasis (HR, 0.98; 95% CI, 0.98-0.99), the time from metastasis to SBRT (HR, 0.98; 95% CI, 0.98-0.99), and breast cancer histology (HR, 0.12; 95% CI, 0.07-0.37) were significant predictors of OS. In an exploratory analysis, a candidate classifier using expression levels of 3 microRNAs (miR-23b, miR-449a, and miR-449b) predicted survival among 17 patients who had primary tumor microRNA expression data available. CONCLUSIONS: A subset of oligometastatic patients achieves long-term survival after metastasis-directed SBRT. Clinical features and primary tumor microRNA expression profiling, if validated in an independent dataset, may help select oligometastatic patients most likely to benefit from metastasis-directed therapy. Cancer 2016;122:2242

De�novo metastatic breast cancer: Subgroup analysis of molecular subtypes and prognosis

“…There is no common definition for oligometastasis and the number of metastatic lesions is generally defined as the criterion. A number of studies (33)(34)(35) defined the incidence of no more than five metastatic sites as oligometastasis. The present study defined that patients with single organ metastasis and <5 metastatic lesions were classified into oligometastasis group, and the rest belonged to the polymetastasis group.…”

Survival, local control, and health‐related quality of life in patients with oligometastatic and polymetastatic spinal tumors: A multicenter, international study

“…Prolonged survival previously has been linked with oligometastatic cancer. 9,[15][16][17] The proponents of oligometastatic theory favor ablative local therapy for the treatment of metastases because the theory suggests that the oligometastatic tumors have limited propensity for dissemination and growth and that the local control of metastases may result in prolonged survival or even cure.…”

Local consolidative therapy versus maintenance therapy or observation for patients with oligometastatic non-small-cell lung cancer without progression after first-line systemic therapy: a multicentre, randomised, controlled, phase 2 study

“…Stage IV disease that is limited to only a small number of sites (“oligometastatic” disease) may reflect a more indolent phenotype that could benefit from local ablative therapy (e.g., surgery or radiation) for consolidation, as suggested by some preclinical and translational analyses. (2, 3) Several retrospective and small prospective trials have suggested that local therapy may be beneficial for patients with stage IV NSCLC presenting with limited metastases, (4–7) including a propensity-matched analysis demonstrating a survival benefit for patients receiving aggressive treatment. (8) However, such an advantage has yet to be shown in well controlled, randomized studies.…”