Effect of combining targeted therapies or chemotherapy with stereotactic radiosurgery (SRS) on the prognosis of patients with brain metastases from non-small cell lung cancer (NSCLC).

BACKGROUND

Recent studies suggest that stereotactic radiosurgery (SRS) increases penetration of systemic drugs into the CNS, and induces immune response to tumor-specific antigens on the surface of tumor cells. Radiation treatment concomitant with immunotherapies and biological treatments for brain metastases (BM) can enhance the body’s immune system to fight the tumor.

METHODS

A 10-year retrospective cohort study of 61 patients, 18 years and older, with BM from primary non-small cell lung cancer (NSCLC) tumors was divided into those who received targeted therapy according to tumor cell mutations or immunoexpression, and those who received standard chemotherapy for metastatic NSCLC with BM. All patients received the treatment concomitant with or within 2 months following the SRS procedure. Brain progression-free survival (brain-PFS), overall survival (OS), and Karnofsky performance score (KPS) were compared between the two groups.

RESULTS

Significant differences favoring targeted therapy were observed in brain-PFS (P = 0.001); Five-year OS was 40% vs. 19%, indicating a non-significant trend toward improved survival (P = 0.06). Within the first 6 months, 50% of the chemotherapy group experienced BM disease progression. In contrast, patients receiving targeted therapies showed brain-PFS below 50% over 12 months with a 5-year survival rate of 40%, compared to 19% in the chemotherapy group. After 12 months, 76% of the target group maintained localized brain tumor control (22/30) versus 29% in chemotherapy (9/31) (P = 0.012). Distal BM control was seen in 13% of the targeted therapy group (3/23), while none in chemotherapy exhibited response or control. No significant differences were found in systemic response or systemic PFS between the groups.

CONCLUSION

Targeted therapies together with SRS for BM in patients with primary NSCLC tumors significantly improved response and survival rates. Combining these two modalities produced greater response to treatment for both local and distal metastases, longer survival, and improved overall performance compared to the traditional radiation and chemotherapy. CLINICAL TRIAL NUMBER: Not applicable.