Between 10% and 20% of patients with non-small cell lung cancer have brain metastases at are associated with diagnosis. These distant metastases sharply truncate life expectancy, with overall survival of less than three months without treatment.
Recent research found that for patients with the epidermal growth factor receptor (EGFR) mutation, patients with a single brain metastasis obtain the best outcomes from surgery followed by treatment with EGFR tyrosine-kinase inhibitors (TKIs). The incidence of brain metastases appears to be higher in NSCLC patients with the EGFR mutation.
Brain metastasis. (Source: Creative Commons)
While systemic therapy remains the standard treatment for metastatic NSCLC, for patients with only one brain metastasis, some evidence supports local treatments with whole brain radiation therapy, stereotactic radiosurgery or surgery of both brain and lung lesions instead. Currently, radiotherapy of the brain metastases combined with chemotherapy with or without molecular target therapy is the most common treatment for these patients.
The study enrolled 36 NSCLC patients with one brain metastasis (BM) who had the EGFR mutation and received treatment between Jan. 2012 and Dec. 2014. Of the 36 patients, 12 were female and 24 were male. Researchers followed patients until Dec. 31, 2016.
Of the participants, 16 had consecutive surgical resection of their brain and lung lesions and subsequent EGFR-TKI therapy. Another 14 had radiotherapy with either simultaneous or subsequent EGFR-TKI therapy and six patients received radiotherapy followed by chemotherapy, either pemetrexed and carboplatin (2) or pemetrexed and cisplatin (4). There were no significant differences between patients in the three groups at baseline.
For the entire cohort, progression-free survival was 12.4 months and overall survival as 19.3 months. Patients who received the surgery/EGFR-TKI combination had the longest progression-free and overall survival, 16.1 months and 28 months, respectively. The next most effective treatment was the radiotherapy/EGFR-TKI combination, which had a progression-free survival of 10.4 months and an overall survival of 16.4 months. Participants who received the radiotherapy/chemotherapy combination achieved a progression-free survival 9.8 months and overall survival of 15.8 months.
The investigators noted that surgical resection of the brain and lung lesions allow analysis of the mutations present in both tumors, which may differ, as happened in one patient in this study. That patient had an exon 19 deletion and EGFR mutation in the lung, but EGFR wild type in the brain tumor. This can guide more individualized therapy, the authors stated.
They also reported that EGFR-TKIs appear to cross the blood-brain barrier, unlike most chemotherapies.
“Surgery combined with EGFR-TKIs could be a recommended treatment for EGFR mutated NSCLC patients with solitary BM,” the researchers concluded.