Analysis of circulating tumour DNA to identify patients with epidermal growth factor receptor-positive non-small cell lung cancer who might benefit from sequential tyrosine kinase inhibitor treatment.

BACKGROUND: Survival data support the use of first-line osimertinib as the standard of care for epidermal growth factor receptor (EGFR)-positive non-small cell lung cancer (NSCLC). However, it remains unclear whether upfront osimertinib is superior to sequential first- or second-generation tyrosine kinase inhibitors (TKIs) followed by osimertinib for all patients. It is impossible to predict which patients are at high risk of progression, and this constitutes a major limitation of the sequential TKI approach. PATIENTS AND METHODS: A total of 830 plasma samples from 228 patients with stage IV, EGFR-positive NSCLC who were treated with first-line TKIs were analysed by digital polymerase chain reaction (dPCR). RESULTS: The circulating tumour DNA (ctDNA) levels helped to identify patients with significantly improved survival rate, regardless of the treatment. Patients treated with first- or second-generation TKIs (N = 189) with EGFR mutations in plasma at a mutant allele frequency (MAF) <7% before treatment initiation (low-risk patients) or who were ctDNA negative after 3 or 6 months of treatment and with an MAF <7% at diagnosis (high responders) had two-thirds lower risk of death than patients in the opposite situation (adjusted hazard ratio [HR] = 0.38; 95% confidence interval [CI]: 0.23-0.64 and HR = 0.22; 95% CI: 0.12-0.42, respectively). The median overall survival (OS) for low-risk patients and high responders treated with first- or second-generation TKIs was 34.2 months and not reached, respectively, regardless of second-line treatment. There were no significant difference in OS between low-risk or high-responder patients treated upfront with osimertinib (N = 39) and those treated under a sequential approach with osimertinib (N = 60). Median OS was not reached in both cases. CONCLUSIONS: Pre-treatment ctDNA levels identify low-risk patients, who may benefit from sequential TKI treatment. Information regarding EGFR mutation clearance can help to improve patient selection.

Sex is a strong prognostic factor in stage IV non-small-cell lung cancer patients and should be considered in survival rate estimation.

BACKGROUND: Biological differences between the sexes have a major impact on disease and treatment outcome. In this paper, we evaluate the prognostic value of sex in stage IV non-small-cell lung cancer (NSCLC) in the context of routine clinical data, and compare this information with other external datasets. METHODS: Clinical data from stage IV NSCLC patients from Hospital Puerta de Hierro (HPH) were retrieved from electronic health records using big data analytics (N = 397). In addition, data from the Spanish Lung Cancer Group (GECP) Tumor Registry (N = 1382) and from a published study available from the cBioPortal (MSK) (N = 601) were analyzed. Survival curves were estimated using the Kaplan-Meier method. A Cox proportional hazards regression model was used to assess the prognostic value of sex. A meta-analysis to compare the outcome for males and females in terms of overall survival (OS) and progression free survival (PFS) was performed. RESULTS: The median OS time was 12 months for males and 19 months for females (overall HR = 0.77; 95% CI: 0.68-0.87; P < 0.001). Similarly, females with stage IV NSCLC harboring an EGFR-sensitizing mutation lived significantly longer than males (median OS: males, 19 months; females, 32 months) with a lower risk of death compared with males (overall HR = 0.75; 95% CI: 0.67-0.84). In addition, female patients benefited more from EGFR inhibitors in terms of PFS and OS (overall HR = 0.45; 95% CI: 0.32-0.64, and HR = 0.62; 95% CI: 0.48-0.80, respectively). Median PFS was 21 months in females and 12 months in males (P < 0.001). CONCLUSIONS: Using routine clinical data we confirmed the previous finding that among stage IV NSCLC patients, females had a significantly better prognosis than males. The effect size of the sex was notable, highlighting the fact that survival rates are usually estimated and patients are generally managed without considering the sexes separately, which may lead to suboptimal results.