Ali AYTAÇ, Ahmet AVCI, Bilgin DEMİR, Esin OKTAY
Meandros Medical and Dental Journal - 2026;27(2):226-232
Objective: This study examines HER2 status impact on treatment outcomes in advanced gastric cancer patients receiving first-line chemotherapy plus trastuzumab. Materials and Methods: A retrospective analysis of hospital records for 216 metastatic gastric cancer patients from August 2013 to April 2022 was conducted. This single-center study compared clinicopathological characteristics, treatment response, and survival outcomes of patients receiving trastuzumab with chemotherapy as first-line therapy. The research compared two HER2-positive groups: IHC 2+/FISH positive and IHC 3+ status. Results: The cohort had 144 patients, with 45 (31.3%) HER2 positive. Among HER2-positive patients, 12 (26.7%) were IHC 2+/FISH positive, and 33 (73.3%) were IHC 3+. Clinical and pathological characteristics, including patient features and histological variants, as well as treatment and survival data, were evaluated. Findings revealed no significant differences in treatment efficacy between the two HER2-positive groups. Objective response and disease control rates were comparable, with 50% and 75% vs. 54.8% and 80.6%, respectively (p=0.775 and 0.683). Progression-free survival was similar, with a median of 8.5 months (95% CI, 3.6 to 13.4) in the IHC 2+/FISH positive group and 9.6 (95% CI, 5.3 to 13.9) months in the IHC 3+ group (p=0.88). Overall survival showed no statistically significant difference, with median durations of 13.2 (95% CI, 11.2 to 15.2) months and 16.2 (95% CI, 11.8 to 20.6) months for the IHC 2+/FISH positive and IHC 3+ groups, respectively (p=0.38). Conclusion: Results suggest first-line chemotherapy plus trastuzumab efficacy in advanced gastric cancer is comparable across different HER2-positive statuses, indicating equal effectiveness for patients with either IHC 2+/FISH positive or IHC 3+ HER2 status. This information helps clinicians make informed decisions regarding treatment strategies for HER2-positive advanced gastric cancer patients.
