Efficacy of Trastuzumab and Potential Risk Factors on Survival in Patients with HER2-Positive Metastatic Gastric Cancer

Abstract

Aim: To evaluate the efficacy of trastuzumab and potential risk factors on survival in patients with HER2-positive metastatic gastric cancer. Methods: We retrospectively included 138 patients who were given trastuzumab-based chemotherapy as first-line treatment and analyzed the relationship between clinical response rates and maintenance treatment status and survival outcomes. Results: In the whole group, the median progression-free survival and overall survival were 10.2 and 16 months, respectively. Clinical response was obtained in 79% of patients. The median overall survival was 16.9 months in follow-up group and 19.0 months in the maintenance group in patients with clinical response. Continuation of maintenance trastuzumab created a significant survival advantage (p = 0.021). Eastern Cooperative Oncology Group performance status 2 (hazard ratio [HR]: 2.02), grade 3 (HR: 1.78) and more than four metastatic lesions (HR: 1.67) were determined as risk factors for death. Conclusion: We recommend the continuation of maintenance trastuzumab in patients with clinical response, but those with identified risk factors may not benefit from treatment because life expectancy may be low.

Gastric cancer has a poor prognosis despite available treatments. Inclusive studies are still needed with real-life data. Our research retrospectively evaluated the efficacy of trastuzumab and potential risk factors on survival in patients with HER2-positive metastatic gastric cancer who received trastuzumab-based chemotherapy as first-line therapy. In total, 138 patients were included in this study. Clinical response to trastuzumab-based chemotherapy was obtained in 79% of the patients. We also divided the patients who had a clinical response into two groups according to whether they received maintenance therapy. In the present study, trastuzumab administration had compatible survival outcomes with recent studies. Continuation of trastuzumab maintenance treatment provided a survival advantage in patients with clinical response. We suppose that maintenance trastuzumab may be recommended in patients with clinical responses to the first-line treatment. Furthermore, Eastern Cooperative Oncology Group Performance Status 2, grade 3 and having more than four metastatic lesions were determined as risk factors for death. Therefore, although we recommend maintenance of trastuzumab in patients with clinical response, those with identified risk factors may not benefit from treatment.

Keywords:

• clinical response
• efficacy
• first-line treatment
• gastric cancer
• HER2
• maintenance
• real-life data
• risk factor
• trastuzumab

Acknowledgments

The authors thank Dr. Hakan Mursaloglu for help during the study period.

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval (reference number: 16/329) and have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.

Availability of data & material

The datasets generated and analyzed during the current study are available from the corresponding author on reasonable request.