The Study: Patients who are fit enough for lung surgery are surely fit enough for lung SBRT, so why not do both with the hopes of maximizing efficacy? The single-arm phase 2 MISSILE-NSCLC trial enrolled 40 patients with medically operable early-stage (≤T2N0) NSCLC. They all received upfront SBRT of 18 Gy x 3 (if peripheral, n=9), 11 Gy x 5 (if >3 cm in size or abutting chest wall, n=21), or 7.5 Gy x 8 (if ≤ 2 cm from brachial plexus or mediastinum, n=10). Lobectomy or sublobar resection was planned for 10 weeks after completion of SBRT, and this happened in 36 patients—one could not get surgery due to radiation pneumonitis. At time of surgery, 3 of 36 (9%) were found to have pathologic nodal involvement. One path specimen was processed wrong and could not be assessed. Oops. So the primary endpoint of complete pathologic response rate was found in 21 of 35 specimens (60%). What’s more, for resected patients, peri-operative mortality rate at 90 days was 0% and estimated local control at 2 years was 100%. Unfortunately, regional recurrence eventually declared itself in 19 of 36 patients (53%).
Bottom Line: Pathologic complete response rates at time of resection of early-stage NSCLC are higher with neoadjuvant SBRT than with immune checkpoint inhibitors with marginal increase in toxicity, but the oncologic benefit stills needs to be elucidated. | Palma, JAMA Oncol 2019