Breast cancer is the most commonly diagnosed cancer among women worldwide, and is a leading cause of cancer-related deaths. When diagnosed at an early stage, appropriate and timely treatment results in a high cure rate and better quality of life. Delays in initiating anti-cancer therapy, including surgical resection, adjuvant/neoadjuvant chemotherapy and radiation therapy are commonly encountered, even in developed health care systems. Existing comorbidities that mandate referral to other services, genetic counseling and testing that may dictate the extent and type of anti-cancer therapy and insurance coverage, are among the most commonly cited factors. However, delays can be unavoidable; for over three years, health care systems across the globe were busy dealing with the unprecedented COVID-19 pandemic. War across hot zones around the globe resulted in millions of refugees; most of them have no access to cancer care, and when/where available, there may be significant delays. Thus, cancer patients across the globe will probably continue to suffer from significant delays in diagnosis and appropriate treatment. Many retrospective reports showed significant negative impacts on different aspects of treatment outcomes and on patients’ psychosocial wellbeing and productivity. In this paper, we review the available data on the impact of delays in initiating appropriate treatment on the outcomes of patients with early-stage breast cancer.