Abstract: Objective To compare the clinical efficacy, adverse events, and immunological function status after medication of icotinib and gefitinib in the treatment of advanced lung adenocarcinoma patients with epidermal growth factor receptor (EGFR) mutations. Methods A total of 176 patients with EGFR mutation⁃positive lung adenocarcinoma confirmed by pathological biopsy at Guangxi Medical University Cancer Hospital from January 2012 to December 2019 were selected as the objects of study, and divided into the icotinib group and gefitinib group according to the targeted treatment regimen. The treatment efficacy were evaluated according to the RECIST 1.1 standard. The incidence of adverse reactions, differences of cellular immunity and humoral immunity indexes were compared between the two groups. Results There was no significant difference between icotinib and gefitinib in terms of objective response rate (60.0% vs 63.2%), disease control rate (94.0% vs 92.1%), median progression⁃free survival (9.5 months vs 8.9 months), median overall survival (21.7 months vs 18.5 months ) as well as overall incidence of adverse reactions (31.0% vs 34.2%) (all P>0.05) . There was no significant difference of cellular immune indicators (CD3⁺T cells, CD4⁺T cells, CD8⁺T cells, CD4⁺/CD8⁺, natural killer cells) and humoral immune indicator IgM between two groups (all P>0.05). However, the levels of humoral immune indicators IgG and IgA in gefitinib group were higher than those of icotinib group (all P<0.05). Conclusions The clinical efficacy and adverse events of icotinib and gefitinib are similar in the treatment of advanced lung adenocarcinoma patients with EGFR mutation⁃positive. The cellular immune functions of the two groups are also similar, but the levels of humoral IgG and IgA in gefitinib group are slightly higher than those in icotinib group.

Key words: Lung adenocarcinoma, Gefitinib, Icotinib, Clinical efficacy, Immune function