Science and Education Publishing American Journal of Cancer Prevention 2328-7314 3 5 2015 10 08 The Ki-67 index in non-Hodgkin's Lymphoma: Role and Prognostic Significance 100 102 EN Mehrdad Payandeh Masoud Sadeghi Student Research Committee, Kermanshah University of Medical Sciences, Kermanshah, Iran Edris Sadeghi AJCP2015357 10.12691/ajcp-3-5-7 2015 05 20 2015 09 10 2015 10 08 Background: Ki67 is a nuclear and nuclear protein antigen present in all proliferating cells during the active part of the cell cycle: G1, S, G2, and mitosis. The aim of study is to evaluate survival based on Ki67 index in NHL patients in the west of Iran for the first time. Patients and Methods: Between of 2002 to 2014, fifty-six patients with NHL referred to Our Clinic. We checked age, sex, type of NHL, Ki67 index and survival for them. We divided Ki67 index to two groups: low Ki67 (Ki67<65%) and high Ki67 (Ki67≥65%). Results: The mean age at diagnosis for patients was 47.33±166.50 years (range, 13-77 years) that 27 patients (48.2%) had age≤ 50 years and 33 patients (58.9%) were male. Thirty-eight patients (67.9%) had Ki67<60% and 18 patients (32.1%) had Ki67≥65%. The mean Ki67 for Nodal patients was 48.1% and for extra nodal was 54.5%, but there was no significant correlation between them (P=0.360). Conclusion: Ki67 in future studies should be divided based on a fix percent until we can have a better result about the role of Ki67 in NHL patients. Also, Ki67 alone can not be a risk factor in NHL patients and other factors such as age, sex and type of NHL can be affective, too.