Correct!
2. Begin erlotinib and radiotherapy to her brain lesions
Testing for mutations in epidermal growth factor receptor (EGFR), KRAS, and anaplastic lymphoma kinase (ALK) and tailoring therapy accordingly is widely accepted as standard practice (1). EGFR is expressed on the cell surface of a substantial percentage of non-small cell lung cancers (NSCLCs) (2). In general, EGFR mutations are more commonly observed in patients with adenocarcinomas and no prior history of smoking, as well as in women and those of Asian descent (such as our patient). Use of the EGFR-tyrosine kinase inhibitors (EGFR-TKI) such as erlotinib, gefitinib or afatinib is limited to patients with adenocarcinomas who have known EGFR mutations such as the exon 19 EGFR mutation. In these patients, erlotinib has been shown to be superior to gemcitabine/cisplatin in progression free survival (3). Erlotinib does penetrate the blood-brain barrier while traditional chemotherapy generally does not. Although brain metastases can be treated with just radiotherapy such as gamma knife surgery, it leaves the primary tumor and the boney metastases untreated. Therefore, among the selections listed erlotinib and radiotherapy is the best choice.
Erlotinib was begun and gamma knife surgery of the brain metastases were performed. Six months later the lung lesion had shrunk from 3.8 to 1.3 cm. Ten months after beginning therapy her brain MRI was normal, and the bone changes were stable by MRI. However, a new 2.6 cm nodule in the left lower lobe was detected on thoracic CT scan.
What should be done at this time? (Click on the correct answer to proceed to the sixth of seven pages)