ABSTRACT Objective: To evaluate the effects of trastuzumab on overall survival (OS) and progression-free survival (PFS) in patients with HER2-positive metastatic gastric cancer.
Study design: Descriptive study.
Place and duration of study: Department of Medical Oncology, Dr. Abdurrahman Yurtaslan Oncology Training and Research Hospital, from January 2012 to December 2019.
Methodology: Medical records of 33 HER2-positive metastatic gastric cancer patients who had received trastuzumab combined with chemotherapy at least 6 cycles and/or followed by maintenance as the first-line treatment were examined. Kaplan-Meier method was used for survival analysis. Log-Rank test was used to compare survival times. The prognostic factors were determined by Cox regression analysis.
Results: The median OS was 15.97 months, and the median PFS was 11.11 months. The median OS and PFS were significantly higher in those who demonstrated partial or complete response to trastuzumab combination treatment, and those who received more than 10 cycles of trastuzumab. A Cox regression analysis revealed that the risk of death was 3.18 times higher in patients with stable disease and 0.44 times lower in patients who received more than 10 cycles of trastuzumab as maintenance.
Conclusion: The OS time was prolonged when the partial and complete response was obtained with chemotherapy combined with trastuzumab, as well as OS and PFS times were improved with the increasing number of trastuzumab cycles. Thus, it is concluded that the response better than stable disease of trastuzumab treatment and an increased number of cycles predicts improved survival efficiently in patients with HER2-positive metastatic gastric cancer. Key Words: Metastatic gastric cancer, Trastuzumab, Prognosis, Response, Efficiency.