This research project aims to analyze whether methadone is a more effective treatment for cancer-related pain compared to first-line opioids like morphine and fentanyl. The study will focus on registered nurses' experiences and preferences in pain management for cancer patients. The research methodology involves qualitative primary research using a questionnaire. The research design is exploratory, aiming to enhance the understanding of pain management for cancer-related pain. The data will be collected through a questionnaire sent via email to 30 selected registered nurses. Thematic data analysis will be used to analyze the collected data and answer the main research question.