Abstract 1233P
Background
The aim was to retrospectively evaluate the prognostic factors for patients of stage IV lung adenocarcinoma with EGFR mutation after EGFR-TKIs compared with radiotherapy (RT).
Methods
From Jan, 2015 to Dec, 2020, 205 patients were included. There were 86 in males and 119 females. The median age was 60 (21-86). There were 83 with exon 19, 100 with exon 21, and 22 cases with other EGFR mutations.
Results
The follow-up time ended on 30 December, 2020. The median dose of RT was 50Gy (10-66Gy). Acute side effects during RT were 34.6% with grade Ⅰ-Ⅱ and 3.4% with grade Ⅲ-Ⅳ, respectively. The 1-year and 3-year OS, PFS1, PFS2 were 86.5% and 43.6%, 56.1% and 16.8%, 78.0% and 32.6%, respectively. Univariate analysis showed that, age (34.1 in ≤60 vs 25.1 months in > 60 ages, p=0.033) and clinical stage (34.8 in IVA vs 27.4 months in IVB stage, p=0.007) were associated with OS; types of TKIs (14.4 in gefitinib vs 14.1 in icotinib 14.7 in erlotinib vs 6.8 in osimertinib vs 3.4 months in others), the timing of RT (20.9 in non-PD vs 13.6 months in PD group), the dose of RT (12.3 in < 50 Gy vs 15.5 months in ≥50Gy group), and the total therapeutic response (18.2 in CR+PR vs 11.0 months SD+PD group) were related with PFS1; clinical stage (30.2 in IVA vs 21.2 months in IVB stage, p=0.023), the types of TKIs, the total therapeutic response (32.5 in CR+PR vs 18.7 months SD+PD) were related with PFS2. The COX multivariate analysis showed that age, clinical stage, the total therapeutic response and the sequence of TKI and chemotherapy (CT) (TKIs alone vs TKIs simultaneous CT vs TKIs sequential CT vs CT sequential TKIs) were independent factors for OS; clinical stage, timing of RT (RT at no-PD vs PD), type of TKIs and the total therapeutic response were independent factors for PFS1; clinical stage, the type of TKIs and total therapeutic response were independent factors for PFS2. Subgroup analysis showed that, patients of RT for primary tumor have better OS, PFS1 and PFS2.
Conclusions
TKI combined with RT was well-tolerated, and RT during non-PD could increase PFS1. The type of TKIs was related with PFS1 and PFS2.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.