Breast cancer is the most common tumor in females. Several different therapeutic modalities are used to treat breast cancer and they consist of surgical approach, radiotherapy, chemotherapy, hormone therapy, and immunotherapy. There are two types of surgical treatment, breast conserving surgery and mastectomy. Breast conserving surgery in combination with adjuvant radiotherapy brings the same results as mastectomies. Systemic therapy is given adjuvantly with early breast cancer, before or after surgery. Chemotherapy is performed with cytostatics that prevent the division of malignant cells. Side effects of chemotherapy are most often hair loss, nausea, vomiting, hematological changes. Long term side effects include cardiotoxicity and cognitive dysfunction. Hormone therapy can be used for tumors that have estrogen receptors, the most common side effects are osteoporosis, heat waves, and there is also an increased risk of developing endometrial cancer. Immunotherapy is a new approach in the treatment of breast cancer and is still being explored. Side effects of immunotherapy include inflammation, gastrointestinal problems, and skin changes. The most common side effects of radiotherapy are skin changes such as redness, erythema and desquamation, followed by lymphedema, and less frequently secondary cancers.