<i>EGFR</i> mutation testing, treatment and survival in stage I–III non-small-cell lung cancer: CancerLinQ Discovery database retrospective analysis

<b>Aim:</b> To describe real-world biomarker testing, treatment and survival in stage IA–IIIC non-small-cell lung cancer (NSCLC). <b>Methods:</b> Electronic records of USA-based patients in the CancerLinQ Discovery^® database with stage IA–IIIC NSCLC (diagnosed between 2014 and 2018) were screened; a curated cohort of 14,452 records was identified for further analysis. <b>Results:</b> Of 3121 (21.6%) patients who had <i>EGFR</i> testing, 493 (15.8%) were <i>EGFR-</i>mutation positive. Of 974 patients who underwent surgical resection, 513 (52.7%) received adjuvant therapy. A quarter of patients with <i>EGFR-</i>mutation positive NSCLC received targeted adjuvant therapy. <b>Conclusion:</b> Approximately a fifth of patients underwent <i>EGFR</i> testing; biomarker testing is important to ensure optimal outcomes for patients with stage I–III NSCLC. <b>A study investigating how many patients with early-stage non-small-cell lung cancer (NSCLC) had mutations in a protein called EGFR and which treatments they received in routine clinical practice:</b> The treatment recommended by medical experts for stage IA–IIIA non-small-cell lung cancer (NSCLC) is surgical removal of the growth (tumor). Patients with stage II or III, and some with stage IB disease, are recommended to receive treatment with medications such as chemotherapy or oral cancer treatments after surgery (adjuvant treatment). In some lung cancers, there are mutations in a protein called EGFR. Osimertinib, a drug that blocks the activity of mutated EGFR on cancer cells, reducing their growth and spread, is recommended as an adjuvant treatment for patients with <i>EGFR</i>-mutated, stage IB–IIIA NSCLC. This study aimed to understand how many patients with stage I–III NSCLC have tumors with <i>EGFR</i> mutations, and which treatments patients received in everyday clinical practice, before new medicines such as osimertinib (that treat <i>EGFR</i>-mutated NSCLC) were recommended. We looked at anonymous data from 14,452 patients with stage I–III NSCLC treated at cancer clinics in the USA between 2014 and 2018. We found that 3121 (21.6%) patients had an EGFR mutation test and 493 (15.8%) had <i>EGFR-</i>mutation positive NSCLC. Of patients who had surgery to remove the tumor, 55% received adjuvant therapy (treatment after surgery). It is important to perform <i>EGFR</i> mutation testing in patients with stage IB–IIIA NSCLC so that patients with <i>EGFR-</i>mutation positive NSCLC can receive appropriate treatment. Stage I–IIIA non-small-cell lung cancer (NSCLC) is typically treated surgically; adjuvant chemotherapy is recommended in patients with stage II/III, and select stage IB disease. Osimertinib, an epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor, is now approved for adjuvant treatment of resected <i>EGFR-</i>mutation positive stage IB–IIIA NSCLC. Immunotherapies have also been recently approved as neoadjuvant or adjuvant treatment in resectable NSCLC. Given these recent advancements, we assessed real-world biomarker testing patterns, and treatment and survival of patients with stage I–III NSCLC using data from the CancerLinQ Discovery^® database, a health information platform that collects real-world data from oncology clinics in the USA. A cohort of 14,452 adults patients diagnosed with stage IA–IIIC NSCLC between January 2014 and December 2018 was identified. Of this cohort, 21.6% had at least one <i>EGFR</i> mutation test between the index date (date of diagnosis) and end of follow-up, with around two-thirds of these tests performed in the first 60 days following NSCLC diagnosis. Frequency of <i>EGFR</i> testing increased with increasing severity of NSCLC disease stage; female and Asian patients were more likely to receive an <i>EGFR</i> test. Of those with an <i>EGFR</i> test, 15.8% had <i>EGFR-</i>mutation positive (<i>EGFR</i>m) NSCLC; <i>EGFR</i>m NSCLC was more common in females, non-smokers and Asian patients. Surgical resection was the most common treatment for stage I and II NSCLC, while systemic therapy and/or radiotherapy without surgery was most common in stage III disease. Among patients who had resection, almost half did not receive a neoadjuvant or adjuvant treatment. Survival decreased with increasing disease stage; among patients with known <i>EGFR</i> status, median overall survival was longer in patients with <i>EGFR</i>m NSCLC than those with <i>EGFR</i>wt NSCLC.