Background and importance Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are the preferred firstline treatment for non-small cell lung cancer (NSCLC) in patients with an activating EGFR mutation. TKIs have consistently shown a greater response, longer progression free survival (PFS) and improved quality of life compared with chemotherapy in patients who have a driver mutation in the EGFR gene.

Aim and objectives To analyse the survival impact of gefitinib on patients with lung adenocarcinoma with the activating tyrosine kinase mutation of the EGFR (EGFR-TK) and to study its safety.

Material and methods This was an observational retrospective study carried out between July 2015 and March 2018. All patients with NSCLC undergoing treatment with gefitinib were included. Patient data were taken from clinical records. Variables analysed were demographics (age and sex), clinical variables (diagnosis, stage, line of treatment, dose administered and performance status (PS) according to the ECOG scale) and other variables (smoking). Efficacy end point was progression free survival (PFS) assessed by RECIST 1.1 criteria. Adverse reactions and comorbidities were also assessed. Analysis of PFS was performed using the Kaplan–Meier curve (SPSS V.17).

Results Thirty-one patients were included with activating EGFR mutations: 74.2% were women, average age was 69.5±11.4 years, 64.28% had ECOG-PS 0–1 and 28.57% were current or past smokers. NSCLC stage was IV in 100% of patients. Regarding comorbidities, 58.1% suffered from high blood pressure, 25.8% from diabetes, 16.1% from coronary heart disease, 29% from asthma/chronic obstructive pulmonary disease and 3.2% from chronic kidney disease.

Patients started therapy with gefitinib as firstline therapy in 58.1% of cases, 12.9% as secondline and 29% as thirdline. One patient stopped his treatment after 1 week due to diarrhoea. Median PFS was 7 months (95% CI 3–12). Adverse reactions included digestive toxicity: 22.57% of patients developed grade 1 (G1) diarrhoea and 14.28% G1 cutaneous toxicity. Other toxicities were conjunctivitis in 3.57% of cases. None of these was related to the comorbidities that patients presented at diagnosis.

Conclusion and relevance Gefitinib showed similar efficacy to the Interest phase III study (n=44) and slightly lower efficacy than the Ipass (n=261) and Isel (n=189) phase III studies (PFS 9.5–10.8). Further analysis in real world situations is necessary to accurately assess PFS. In general, gefitinib was well tolerated.

References and/or acknowledgements No conflict of interest.