Therapeutic effect of cranial radiotherapy with or without anlotinib treatment for lung cancer patients with brain metastasis and non-EGFR/ALK-TKIs indication

Abstract Background: Cranial radiotherapy (CRT) is the main treatment for lung malignant tumor with brain metastasis (BM) and lacking EGFR/ALK-TKIs indication. For non-small cell lung cancer with BM, anlotinib can improve progression free survival (PFS). We retrospectively analyzed the clinical effects of anlotinib + CRT versus CRT alone.Methods: In patients with lung cancer (adenocarcinoma, squamous carcinoma, or small cell carcinoma) with BM and non-EGFR/ALK-TKIs indication, the overall survival (OS) and PFS of anlotinib + CRT treatment versus CRT treatment alone were separately calculated and compared. The Cox proportional hazards model was used to analyze the independent prognostic factors for intracranial PFS (iPFS) and OS. All confounding factors were adjusted, including age, gender, Karnofsky Performance Status (KPS) score, smoking history, physiological characteristics, T/N stage, histology, metastases, and pathological characteristics. Subgroup analysis for iPFS and OS was performed to assess the effects on BM of treatment pattern.Results: The study included 100 patients with BM at baseline and the follow-up data. Of the 100 patients, 67 patients received CRT treatment alone and 33 patients received CRT + anlotinib treatment. The overall response rates of the CRT + anlotinib group and the CRT alone group were 90.91% and 83.58%, respectively. There was significantly more iPFS in the CRT + anlotinib group compared to CRT alone (median iPFS [miPFS]: 9.0 vs 3.0 months; hazard ratio [HR] 1.59; 95% confidence interval [CI] 1.01-2.52; p = 0.038). The OS, extracranial PFS (ePFS), and systematic PFS (sPFS) of CRT + anlotinib group were longer than those of the CRT alone group, but there was no significant statistical difference (median OS [mOS]: 9.0 vs 7.0 months, HR 1.17, 95% CI 0.74-1.85; median ePFS [mePFS]: 9.0 vs 7.0 months, HR 1.23, 95% CI 0.72-2.11; median sPFS [msPFS]: 7.0 vs 4.0 months, HR 1.37, 95% CI 0.82-2.30). The Cox proportional hazards model analysis revealed that age was an independent prognostic factor of iPFS (HR 1.65, 95% CI 1.05-2.59, p = 0.03). Age (HR 1.74, 95% CI 1.09-2.77, p = 0.02) and KPS score (HR 1.88, 95% CI 1.17-3.01, p = 0.01) were identified as independent prognostic factors of OS. Further subgroup analysis of iPFS showed that when the number of BM in the CRT + anlotinib group was less than or equal to three lesions (≤ 3), the miPFS (12.0 months) was significantly longer than that for CRT alone (> 3) (3.0 months), for CRT alone (≤ 3) (3.0 months), and for CRT + anlotinib (> 3) (7.0 months) (p = 0.014). The OS of the CRT + anlotinib group (≤ 3) (mOS 37.0 months) was much longer than that in CRT alone (> 3) (mOS 6.0 months), CRT alone (≤ 3) (mOS 7.5 months), and CRT + anlotinib (> 3) (mOS 8.5 months) groups, but this difference was not statistically significant (p = 0.051).Conclusion: Anlotinib can improve the survival of patients with lung cancer BM, with better efficacy of a combined treatment of anlotinib + CRT compared to that of CRT alone, especially for the iPFS of patients with BM ≤ 3.