Efficacy and mechanism of osimertinib combined with bevacizumab in the treatment of postoperative EGFR positive stage II-IIIA lung adenocarcinoma.

Objective: To explore the efficacy and mechanism of osimertinib combined with bevacizumab in treating postoperative epidermal growth factor receptor (EGFR) positive stage II-IIIA lung adenocarcinoma.

Methods: In this retrospective study, one hundred and thirty patients with postoperative EGFR positive stage II-IIIA lung adenocarcinoma were divided into two groups according to different treatment methods. Patients treated with osimertinib alone were included in the single group (65 patients). Patients treated with bevacizumab on the basis of the single group were included in the joint group (65 patients). The short-term efficacy, side effects and survival results of the two groups were counted. The changes of serum vascular endothelial growth factor, serum tumor markers and life quality before and after the treatment were observed.

Results: The ORR (66.15%) and DCR (86.15%) in the joint group were significantly higher than those in the single group (47.69% and 70.77%) (both P<0.05). The serum levels of VEGFA, VEGFB, VEGFC, BFGF, HDGF, SDF-1, CEA, CA153, CYFRA21-1 and CA199 in the joint group were lower than those in the single group after the treatment (all P<0.05). No significant difference was shown in the incidence of adverse reactions such as rash, diarrhea, constipation, albuminuria, hypertension and interstitial pneumonia between the joint group and the single group (all P>0.05). After the treatment, the ZPS score of the joint group was lower than that of the single group, and the KPS score was higher than that of the single group (both P<0.05). There was no significant difference in the two-year median DFS and the one or two-year DFS rate between the joint group and the single group (all P>0.05).

Conclusion: Osimertinib combined with bevacizumab in the treatment of postoperative EGFR positive stage II-IIIA lung adenocarcinoma has evident short-term efficacy and mild side effects, which is helpful in improving the disease control rate and life quality. The mechanism may be related to the regulation of serum CEA, CA153, CYFRA21-1, CA199 levels and inhibition of VEGFA, VEGFB, VEGFC, BFGF, HDGF, and SDF-1 levels.