Because of the diversity of cancer biology and multiple treatment options, which include focal therapy(surgical resection and radiotherapy)and systemic therapy, oncology practice is complicated and always challenging for oncologists and patients. To decide on an evidence-based optimal therapy, clinical guideline has a crucial role for physicians. However, there are discrepancies in the contents and accessibility to the guidelines among each. This article mentions the role of guidelines and how they are adapted into practice from the viewpoint of a medical oncologist working at a community hospital.