Analysis of the benefit of sequential cranial radiotherapy in patients with EGFR mutant non-small cell lung cancer and brain metastasis

Although cranial radiotherapy is considered the standard treatment for brain metastasis (BM), EGFR tyrosine kinase inhibitors (TKIs) have shown promising activity in EGFR mutant non-small cell lung cancer (NSCLC) patients with BM. However, the efficacy of sequential cranial radiotherapy in patients with EGFR mutant NSCLC who are treated with EGFR TKIs remains to be determined. Patients with NSCLC who harbored an EGFR mutation and whose BM had been treated with EGFR TKIs were retrospectively reviewed. The clinical outcomes of patients treated with EGFR TKIs alone and those treated with cranial radiotherapy followed by EGFR TKIs (additive therapy) were compared. Of the 573 patients with NSCLC with BM who harbored an EGFR mutation and had received EGFR TKIs, 121 (21.1 %) had BM at the time of initial diagnosis. Fifty-nine (49 %) patients were treated with additive therapy, whereas 62 (51 %) patients were treated only with EGFR TKIs. No significant differences were observed between the additive therapy group and the EGFR TKI alone group regarding intracranial progression-free survival (PFS) (16.6 vs 21.0 months, p = 0.492) or extracranial PFS (12.9 vs 15.0 months, p = 0.770). The 3-year survival rates were similar in both groups (71.9 vs 68.2 %, p = 0.675). Additive therapy consisting of cranial radiotherapy followed by EGFR TKI treatment did not improve OS or intracranial PFS compared with EGFR TKI treatment alone in EGFR mutant NSCLC patients with BM. Further prospective studies are needed to determine the precise benefits of sequential cranial radiotherapy in EGFR mutant NSCLC treated with EGFR TKIs. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12032-016-0811-3) contains supplementary material, which is available to authorized users.