en تومور Tumor surgery پژوهشی Research Article <div style="text-align: justify;"><span style="font-size:14px;"><span style="font-family:Tahoma;"><span style="line-height:2;"><strong>Background and Objectives</strong>: Osteosarcoma (OS) is the most common cause of limb loss due to cancers. This study determines the mean survival time in patients with OS and prognostic factors.<br> <strong>Methods</strong>: This retrospective study was conducted on patients with OS who were referred to Shah Vali Hospital, Yazd, Iran, from 2004 to 2018. The data on patient-related factors (age and sex), tumor-related factors (recurrence, recurrence site, and metastasis), and living status were obtained and analyzed.<br> <strong>Results</strong>: Overall, 29 patients were included, of which 21(72.4%) were male. The mean age of patients was 21.3&plusmn;8.4 (age range of 8-42) years. The tumor site was the lower limb in 23 patients (79.3%), the upper limbs in 4 patients (13.8%), and the axial in 2 patients (6.9%). Meanwhile, 13(44.8%) patients died due to OS, and one (6.9%) died for other reasons. The mean survival time in the subjects was 83.1&plusmn;14.71 months. The 1-year survival of patients was nearly 90%, 3-year survival was about 64%, and 5-year survival was 40%. Also, 7(24.1%) patients had primary metastasis. The mean survival period was 22.25 months in patients with primary metastasis and 98.87 months in patients without primary metastasis (P=0.011). Among the patients, 15(51.7%) had a recurrence, of which 6(20.7%) were local, and 9(31%) were distant recurrences. The mean survival period after the recurrence of patients was 21.27&plusmn;5.07 months.<br> <strong>Conclusion</strong>: The mean survival period, according to sex, age, recurrence, and recurrence site, was not significant; however, it was significant according to metastasis.</span></span></span></div> Osteosarcoma, Survival analysis, Survival, metastasis 209 218 http://jros.iums.ac.ir/browse.php?a_code=A-10-1003-3&slc_lang=en&sid=1 Amir Ebrahimzadeh Babaki Amirebrahimzadeh13@gmail.com 10031947532846006897 10031947532846006897 Yes Department of Orthopedic, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. Fahimeh Ebrahimzadeh Babaki ebrahimzade.7369@gmail.com 10031947532846006898 0009-0004-4800-1448 No Department of Hematology-Oncology, Ali-ebn-Abitaleb Faculty of Medicine, Yazd Branch, Islamic Azad University, Yazd, Iran. Mohammad Reza Mortazavizadeh Mortazavizadeh@yahoo.com 10031947532846006899 10031947532846006899 No Department of Hematology-Oncology, Ali-ebn-Abitaleb Faculty of Medicine, Yazd Branch, Islamic Azad University, Yazd, Iran.