Background: Five-year relative survival rate in cases of osteosarcoma is below 20%. Some scientific evidence suggests that there is a significant association between inflammatory markers and poor prognosis in some tumor types. This study aims to determine the role of the preoperative lymphocyte-to-monocyte ratio (LMR) as a prognostic factor in the life expectancy of osteosarcoma patients at Haji Adam Malik General Hospital (RSUP HAM) Medan. Methods: This study is a retrospective cohort study conducted from January 2019 to February 2020. Samples were taken consecutively on osteosarcoma patients treated at the HAM Hospital from January 2013 to December 2018, whether or not undergoing postoperative adjuvant chemotherapy, with a minimum of total of 24 samples. LMR is classified categorically with the cuff value obtained from the receiver operating characteristic (ROC) curve. Both variables were statistically analyzed using the Kaplan Meier survival curve. Results: The total number of subjects in this study was 45 samples. There were 35 male samples (77.8%) and 10 female samples (22.2%) with the mean age of 21.18 ? 12.381 years. The age group at the time of diagnosis was mostly 11-20 years old, with a total of 23 samples (51.1%). Based on the location, the highest number was found in the distal femur of 17 samples (37.8%). The minimum lymphocyte value was 0.66, and the maximum value was 17.20, with a mean of 3.51?4.36. The minimum monocyte value was 0.36, the maximum value was 15.30, with a mean of 8.34 ? 3.72. The minimum LMR value is 0.36, and the maximum is 15.30 with an average of 8.34 ? 3.73. The cut off value obtained is 0.384. The number of patients with high LMR was 11 samples, with 3 alive samples and 8 deceased samples, while at low LMR there were 34 people with 1 alive sample and 33 deceased samples. Based on the Kaplan Meier survival curve, the log rank value was 0.004 with a hazard ratio of 3.143. Conclusion: High preoperative LMR was significantly associated as a prognostic factor of life expectancy in osteosarcoma patients as a good prognostic value in patients

Osteosarcoma

Lymphocyte-monocyte ratio

Prognostic factors