Breast cancer is a complicated and diverse disease where cells in the breast tissue grow out of control. It is the most common type of cancer to affect women worldwide. Breast cancer can arise in the connective tissues, ducts, and lobules, among other places in the breast. Based on their morphological features, breast cancers are currently divided into two categories: invasive and non-invasive. This study aims to determine the relationship between HER2 gene changes and the development of breast cancer. Results could improve early detection, treatment strategies, and targeted medical interventions for individuals with diverse genetic backgrounds. The meta-analysis approach was used in this study. In order to conduct a meta-analysis, the literature must be thoroughly reviewed, and the results and theories that were investigated must be described. Data analysis techniques like funnel plots can be used to determine whether studies were missing, but if the majority of current research was not identified, the results may be inaccurate. The majority of research suggests that the HER2 Ile655Val polymorphism was strongly associated with an increased cancer of breast cancer, particularly among younger women and members of particular ethnic groups. No significant relationship was found in some studies, which may indicate sample size limitations or population-specific effects.