The prevalence of chronic pain ranges from 30-50% in patients. A comprehensive pain scale assessment must be carried out because of the high rate of morbidity, opioid dependence, and failure of conventional treatment. Objective pain measurement is expected to improve the quality of chronic pain management for malignancy. This study is aim to explore the kynurenic acid level serum in different type of cancer based on its origin, thus we can further evaluate the pain of cancer therapy based on its origin. Methods: This is a literature review study using electronic database between the years 2011 to 2021. We used Pubmed, Google Scholar, Web of Science databases and analyzed the datas in to comprehensive resumes. Results: Twenty-five articles, identified from 140 abstracts, were included in this review. From the articles we explored kynurenic acid was found in the serum of cancer patients in the range from 21.3 to 250 nM depending on the type of cancer. It is increasing in some kind of cancer, except for primary cervical cancer than healthy people. The level of this biomarker for example colon adenocarcinoma (37.52 nmol/L, lung Adenocarcinoma (107.1 nmol/L), and multiple myeloma (59.23 nmol/L). Kynurenic acid can be a plasma biomarkers of inflammation and kynurenine pathway activity are independent predictors of cancer mortality and the latter can be used as progostotic factors. Conclusion: Kynurenic acid level was different in every cancer origin. It is hypothesized that the biological behaviour of type of cancer alter the action of kynurenine metabolic pathway

Keywords : Kynurenic Acid, Pain, Biomarker, Cancer