In the current case, the patient was nonadherent to her current medicine despite experiencing breast cancer-related symptoms and did not visit the doctor until her hip-joint pain disrupted her daily-living activities. On investigation, she was diagnosed as having advanced-stage breast cancer. The patient's adherence to cancer therapy was influenced by her family's poor experience with cancer therapy. The patient's condition was complex, with simultaneous physical and psychological problems, which adversely affected her cancer therapy and prognosis. She was assessed thoroughly on the basis of Orem's theory during the period of nursing care (March 9-22, 2017). The patient's physical and mental problems were intertwined, affecting her cancer treatment and prognosis. Orem's theory was used to conduct a case-wide overall care assessment during the nursing period (March 9-22, 2017). According to the self-care behavior of the patient, appropriate care measures were provided. Important health problems, such as physical activity disorders, denial of misconduct, and increased self-care ability, are examples. The patient's psychological problems resolved after systematically intervening care measures given by Swanson's theory were applied. The patient was successfully guided to pass the stages of denial and negotiation, accept the disease condition, adhere to the therapy to develop proper self-care and daily-living abilities, and provide appropriate medical information. We emphasize the promotion of the individualized nursing care theory and model to guide cancer patients in developing adequate self-care abilities.