Objectives: This study was undertaken to identify management strategies that maximize survival of patients with stage III non-small cell lung cancer and metachronous brain metastases and to determine whether any apparent improved survival was due to treatment or simply to patient selection.
Methods: Treatment evaluations of both primary non-small cell lung cancer and brain metastases were performed in 91 patients. Optimal treatment was identified by multivariable analysis. Propensity scoring and multivariable analysis were used to separate treatment benefit from patient selection.
Results: Risk-unadjusted median, 12-, and 24-month survivals were 5.2 months, 22%, and 10%, respectively. Younger age (P =.006), good performance status (P =.003), stage IIIA (P =.001), lung resection (P =.02), no other systemic metastases at time of diagnosis of brain metastases (P =.02), and either metastasectomy (P <.001) or stereotactic radiosurgery (P <.001) predicted best survival. However, metastasectomy or stereotactic radiosurgery was more common after lung resection (P =.02) and in patients with good performance status (P =.006), no other systemic metastases at time of diagnosis of brain metastases (P =.01), and fewer brain metastases (P <.001), suggesting that the patients with the best risk profile were selected for aggressive therapy of both lung primary and brain metastases. Despite this selection, analysis of propensity-matched patients demonstrated the benefit of lung resection and metastasectomy or stereotactic radiosurgery (P <.001).
Conclusions: Younger patients with resected stage IIIA non-small cell lung cancer who have isolated metachronous brain metastases and good performance status do best when treated with metastasectomy or stereotactic radiosurgery. This survival benefit is a brain treatment effect, not the result of selecting the best patients for aggressive therapy.