Trastuzumab in Addition to Chemotherapy in Patients With Metastatic Human Epidermal Growth Factor Receptor 2-Positive
M Korpan1, L Simonis2, V Soellner2
1Department of Medicine I, Division of Oncology, Medical University of Vienna, Waehringer Guertel 18-20, A1090, Vienna, Austria; Christian Doppler Laboratory for Personalized Immunotherapy, Medical University of Vienna, Waehringer Guertel 18-20, A1090, Vienna, Austria.
Aims:
Since results of the Trastuzumab for Gastric Cancer (ToGA) trial were published in 2010, the addition of trastuzumab to chemotherapy is the standard of care for first-line treatment of human epidermal growth factor receptor 2 (HER2)-positive metastatic gastroesophageal adenocarcinoma, yet data from European real-world cohorts are scarce.
Materials And Methods:
We evaluated baseline characteristics and treatment regimens of gastroesophageal adenocarcinoma patients with advanced and metastatic disease (stage IV) treated at the Medical University of Vienna between 01/01/2010 and 31/12/2023. Log-rank tests were performed to analyse differences in survival.
Results:
In our cohort of 369 advanced/metastatic gastroesophageal cancer patients, 78 (24%) of tumours with known HER2 status were HER2 positive. First-line chemotherapy with trastuzumab was administered to 60 HER2-positive patients (16% of the overall cohort) and showed statistically significantly improved overall survival compared to patients treated with chemotherapy only (17.3 vs 11.9 months, hazard ratio = 0.62, P =0.0011). Regarding tumour location, 15 (25%) patients had oesophageal cancer, 23 (38%) had cancer of the gastroesophageal junction, and 22 (37%) had gastric cancer. However, no statistically significant survival benefit was observed with the addition of trastuzumab in tumour location subgroups (P = 0.058, P = 0.088, P = 0.07).
Conclusion:
Our data support the results from the ToGA trial in a real-world cohort and underline the importance of HER2 testing and administration of trastuzumab in clinical routine. Although not included in the initial ToGA trial, oesophageal adenocarcinoma patients express HER2 to a significant extent, and further analyses are needed to investigate the benefit of trastuzumab and other anti-HER2 treatment options in this subgroup.
