The most problematic and difficult cases of general surgery applications are cancers. Cancer can be diagnosed in many ways, including the presence of some symptoms and signs, screening tests, and imaging methods. The diagnosis of cancer is confirmed anatomically by microscopic examination of tissue samples. Biomarker research has become increasingly interesting for many medical fields today. Biomarkers are indicators of the biological process that can show changes in disease and health status and reveal pathological conditions. The sensitivity of markers used for early and painless diagnosis is weak in all types of cancer, including thyroid, breast, stomach, pancreatic, and colorectal cancers. Biochemical and molecular markers have been found to be of great importance in cancer research in recent years in the formation mechanisms and treatment steps of cancer. Several biomarkers have been studied in the circulating body fluids and tissue of preoperative, intraoperative, and postoperative patients. The main use of tumor markers is the follow-up of the response to treatment and early detection of recurrences in patients diagnosed with cancer. Tumor markers correctly selected will guide the patient's monitoring and treatment planning. But, still, the field of cancer surgery needs new biomarkers.