P3.01-11 Depression and Inflammation in Patients with EGFR-Mutated Non-Small Cell Lung Cancer

Abstract

Although depression appears to be associated with worse survival outcomes in cancer patients, the underlying mechanisms and basis of this association remain unknown. EGFR mutations have been associated with improved treatment response and prognosis in advanced non-small lung cancer (NSCLC). However, previous reports have described a positive association between this genotype and depression. This relationship could be at least partially explained by TNFa-mediated inflammation, which activates the hypothalamus-pituitary-adrenocortical (HPA) axis, leading to tryptophan depletion through the stimulation of indoleamine 2,3 dioxygenase. 32 patients diagnosed with metastatic NSCLC with an EGFR mutation were enrolled and followed monthly. In all cases patients were evaluated using the Self-rating depression scale (SDS) and the Numeric Rating Scale (NRS) in order to obtain a detailed evaluation of the initial symptoms and a qualitative assessment of the state of depression. In parallel we measured TNFa levels in serum/plasma (MaxDiscovery™ Human TNF-α ELISA Test Kit) upon receipt of genotype report, 4 and 12 weeks after initiating the targeted therapy, and at the time of progression. We examined differences between patients with and without depression with respect to the TNFa, as well as impact on various outcomes. Mean age was 58.9 years (+/- 12.4), 22 (68.8%) were women and 94% had an ECOG <2. Nineteen patients (59.4%) carried a del19, 8 (25%) had L858R, 2 (6.3%) L858R+T790M, 2 (6.3%) G719S and one patient had a del19+S768I (3.1%). Median follow-up was 15.4 months (95%CI 2.8-32.0), overall survival (OS) was 28.1 months (95%CI 25.5-30.6) and median progression-free survival (PFS) to first-line TKI was 13.1 months (95%CI 9.6-16.6).37.5% (n=12) of patients self-reported depression; in 25, 9.4 and 3.1% the clinical manifestations were mild (SDS 50-59; supportive psychotherapy), moderate (SDS 60-69; requirement of antidepressants) and severe (SDS 70 and above; required hospitalization). Depression was significantly associated with moderate-to-severe basal dyspnea (p=0.043), with brain metastases (p=0.003), and poor performance status (p=0.021). The average TNF at the time of genotype report was 12.2 pg/mL (SD±4.1), and was significantly higher in those who manifested depression (p=0.03). TNF levels increased 11% at 4 weeks and 75% at 12 weeks. Depression did not influence OS or first-line PFS. Mild to moderate depression is prevalent in patients with lung cancer harboring EGFR mutations. As previously reported, TNFa levels are elevated in patients with lung cancer and depression, particularly in the first 12 weeks post-treatment, a finding attributable to inflammation.