The continuously increasing number of women diagnosed with breast cancer is one of the biggest challenges the public healthcare system is facing. In the Republic of Croatia, an early breast cancer detection program is enforced to ensure early stage diagnosis so proper treatment could be given in time. Every new and visible change to the breast requires further examination to rule out breast cancer. Before a diagnosis is made, patients must undergo an extensive diagnostic screening which encompasses a clinical examination, radiological screening and a pathohistological evaluation. After the diagnostic screening is concluded, the breast cancer stage and metastatic process of cancer are graded through the TNM classification system. In accordance with that, cancer treatment is decided and the patient begins the treatment. Treating breast cancer includes surgical treatment, radiotherapy, chemotherapy, endocrine therapy, immunotherapy and supportive therapy. The main goal of supportive therapy is the management and mitigation of unwanted symptoms and side effects that occur during the treatment process. Breast cancer treatment causes a wide array of side effects which require additional care, attention and support to help improve the patient's impaired quality of life. Providing supportive therapy is based on a holistic and individual approach which is also the foundation of nursing care. As a part of the multidisciplinary medical team, the nurse knows to recognize when a patient needs assistance with basic human needs, which is then enforced through a nursing intervention. Nursing interventions are focused on providing direct physical assistance as well as psychological and social support.