By Lorraine L. Janeczko
NEW YORK (Reuters Health) - 30/4/2019
"These findings are not entirely surprising given that the relationship between higher doses of radiation therapy and improved survival has been demonstrated in stage-I NSCLC. However, it is interesting that the pattern holds true for stage-II NSCLC, which is less frequently treated with SBRT (stereotactic body radiation therapy)," said Dr. Kimberley S. Mak of Boston Medical Center.
"Surgery-based treatment is the standard of care for patients with stage-II NSCLC who are operable candidates," she told Reuters Health by email. "For patients who are not candidates for resection or who refuse surgery, our findings suggest that SBRT may be an acceptable treatment alternative, especially if they do not have node-positive disease."
Dr. Mak and her colleagues conducted what is, to their knowledge, the first study to investigate a dose-response relationship in patients receiving SBRT for stage-II NSCLC.
The team identified patients in the National Cancer Database (NCDB) who had been diagnosed with stage-II NSCLC and treated with SBRT between 2004 and 2013.
Overall, 0.8% of more than 56,543 patients received SBRT, they reported in Lung Cancer, online April 1. Of these, 360 (79.8%) had node-negative disease and 91 (20.2%) had node-positive disease. The most common prescriptions used 10 Gy x 5 (35.9%) and 12 Gy x 4 (19.3%); the mean BED10 was 114.9 Gy, and the median 105.6 Gy.
Median follow-up was 19.3 months, and overall median survival was 23.7 months. Median survival was 22.4 months among patients treated with BED10 <114.9 Gy, vs. 31.5 months for those exposed to BED10 114.9 Gy or higher (P=0.036).
On multivariate analysis, BED10 as a continuous variable (hazard ratio, 0.991) and 114.9 Gy or higher (HR, 0.63) were significantly linked with improved survival in node-negative patients.
However, neither measure was associated with significantly better survival in node-positive patients.
Dr. Mak recommends that providers take a multidisciplinary approach with all patients, involving, for example, presentations at a multidisciplinary thoracic tumor board to determine each individual's optimal treatment plan.
"Stage-II NSCLC is a heterogeneous group of lung cancers, without a 'one size fits all' approach to treatment," she explained. "If surgery is risky or not an option, a patient with stage-II NSCLC without lymph node involvement might benefit from SBRT, whereas a patient with a small primary tumor with hilar nodal involvement might benefit from a different treatment approach."
The study had no specific funding, and the authors declared no conflicts of interest.
Lung Cancer 2019.