Tumor markers: when, whom?

Cancer is a leading health problem with its prevalence, clinical course and deaths all over the world. It is known that cancer is the second leading cause of death in Turkey after cardiovascular diseases. Therefore, intensive research is carried out on the early diagnosis and treatment of cancer. The most important of these are tumor markers that are still used in clinical practice. Based on this definition, it is theoretically possible to obtain information about the presence of the tumor and the character of the tumor by investigating tumor markers in body fluids. A tumor marker is a molecule that is present in the structure of the tumor cell, secreted by the tumor cell or produced in response to the tumor and can be measured or demonstrated in body fluids. However, its use is limited due to its low sensitivity and specificity to cancer type in the early period. Therefore, it is important to select the appropriate test at the appropriate time for the appropriate patient. In this review, general principles regarding the use of tumor markers were tried to be explained.