Abstract:
Objective To analyze the clinical efficacy and safety of programmed cell death protein 1 (PD-1) monotherapy combined with trastuzumab standard treatment as the first-line treatment for human epidermal growth factor receptor-2 (HER-2)-positive advanced gastric cancer (GC).
Methods A total of 110 patients with HER-2-positive advanced GC who were enrolled in Henan Cancer Hospital from June 2019 to June 2021 were assigned into study group (n=48) and control group (n=62) according to the treatment methods, and the clinical efficacy and safety of the two groups were compared.
Results The median follow-up time was 14.2 months. The study group showed better results compared to the control group in terms of objective response rate (ORR) (41.7% vs.37.1%), disease control rate (DCR) (87.5% vs. 80.6%), and the median progression-free survival (mPFS) (9.2 months vs.6.8 months) (HR=0.624, 95%CI: 0.396-0.981, P=0.046). The mPFS of IHC3+ in the study group and control group was 11.6 months vs. 6.8 months (HR=0.461, 95%CI: 0.260-0.817, P=0.012), mPFS of IHC3+ and IHC2+ (ISH positive) in the study group was 11.6 months vs.7.8 months (HR=0.486, 95%CI: 0.215-1.097, P=0.051), and the mPFS of PD-L1 positive and PD-L1 negative patients in the study group was 9.2 months vs.4.9 months (HR=0.370, 95%CI: 0.104-1.322, P=0.033). Only hypothyroidism (P=0.034) and neutropenia (P=0.046) were statistically different in all adverse events between the study group and control group. Multivariate analysis showed that ECOG score, peritoneal metastasis, and treatment regimens were independent factors of PFS (P<0.05).
Conclusions Immunotherapy combined with trastuzumab standard treatment of HER-2-positive advanced gastric adenocarcinoma has good clinical efficacy and can prolong PFS. The effect of the immune combination treatment may be better with IHC3+ patients, and treatment safety is controllable.