en Pathology Pathology Original Article Original Article <span style="font-size:14px;"><span style="font-family:Times New Roman;"><span style="line-height:14pt"><b><i><span style="color:blue">Background</span></i></b><i><span style="color:blue">:</span></i> Prerequisite for achieving the goals of the registration program is the existence of valid and accurate data, and the usability of this data is possible if they are coded correctly. This study assets the quality of pathological data of the population-based cancer registration centers based on ICD-O-3.<span style="font-size:9.0pt"></span></span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Methods:</span></i></b> This applied study was performed descriptively and retrospectively. The study population included 20129 pathology reports sent to the population-based cancer registration center of Mazandaran Province during 2018-2020. A total of 2015 out of, 2050 samples of the received reports were examined according to stratified random sampling method. A researcher checklist was made to collect the data, and STATA 13&nbsp;and Cohen&#39;s Kappa agreement coefficient were used to analyze the data.<i><span style="font-size:10.0pt"></span></i></span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Results:</span></i></b> Among the 2015 reports of pathology, 1114 (55.3%) pathology reports were related to government centers, (42.9%) 865 cases were registered with their topographic code, morphology and behavior. Based on the registration of the exact topographic code, the kappa coefficient and the total agreement were 0.266 and 27.70%, respectively. Kappa coefficient in all received reports and reports with topographic code was 0.346 and 0.906, respectively. In the reports with topographic code, the most reports of cancers were related to cancers of the gastrointestinal organs (97.6%) 246.<b><i><span style="color:blue"></span></i></b></span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Conclusion</span></i></b><i><span style="color:blue">:</span></i> The accuracy of the codes given in the pathology centers in terms of topographic, morphological, behavioral and grade codes based on the percentage of agreement with the coding was above average, which were higher in governmental centers and also in some cancers.<b><i><span style="color:#0033cc"></span></i></b></span></span></span> Neoplasms, Grade, Assessment, Accuracy, Reliability 589 598 http://caspjim.com/browse.php?a_code=A-10-1864-3&slc_lang=en&sid=1 Raziehsadat Mousavi mousavi.raziehsadat868@gmail.com, 100319475328460042650 100319475328460042650 No Hospital Administration Research Center, Sari Branch, Islamic Azad University, Sari, Iran Ghahraman Mahmoudi ghahraman48@yahoo.com 100319475328460042651 100319475328460042651 No Hospital Administration Research Center, Sari Branch, Islamic Azad University, Sari, Iran Mohammad Ali Jahani drmajahani@yahoo.com 100319475328460042652 100319475328460042652 Yes Social Determinants of Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran Hossein Ali Nikbakht ep.nikbakht@gmail.com 100319475328460042653 100319475328460042653 No Social Determinants of Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran