Tehran University of Medical Sciences Basic & Clinical Cancer Research 2228-6527 10 1 2018 04 18 12 21 EN Mojtaba Vand Rajabpour Cancer Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran AND Clinical Cancer Research Center, Milad General Hospital, Tehran, I.R. of Iran Elena Ghotbi Cancer Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran Sepideh Azizi Cancer Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran Bahram Salmanian Baqiyatallah Research Center for Gastroenterology and Liver Diseases, Baqiyatallah University of Medical Sciences, Tehran, Tehran, I.R. of Iran Hossein Yahyazadeh Clinical Cancer Research Center, Milad General Hospital, Tehran, I.R. of Iran Hossein Khedmat Baqiyatallah Research Center for Gastroenterology and Liver Diseases, Baqiyatallah University of Medical Sciences, Tehran, Tehran, I.R. of Iran Afshin Abdirad Cancer Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran Mohammad Shirkhoda Cancer Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences. Tehran, Iran. Iraj Harirchi Cancer Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran Kazem Zendehdel Cancer Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran AND Cancer Biology Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Iran. 2017 11 13 2018 02 28 Background: We studied the number of lymph nodes (LN) assessed in gastric cancer, and evaluated the association between different factors and a lower number of LN assessed. Methods: We conducted a retrospective study in three hospitals in Tehran city, I.R. Of Iran. We used patient medical and pathological reports and obtained personal and clinical information. We studied the association of being on the N3 stage with the number of assessed lymph nodes (NALN), gender, tumor size, T stage, hospital, tumor site, histopathological diagnosis, tumor grade and age at diagnosis. In addition, we estimated the association between NALN and different clinical variables. A logistic regression model estimated the crude and adjusted odds ratios (OR) and corresponding 95% confidence intervals (95% CI). Results: The average number of NALN was 10.48 (±6.9). We found that the probability of being diagnosed as stage N3 was significantly lower in patients who had less than 15 LN assessed compared to those who had more than 15 LN assessed in their pathology reports (OR=0.2; 95% CI 0.1-0.4). The hospital, tumor sizes were significantly associated with NALN. Conclusion: Lower NALN led to stage migration and underestimation of the real tumor stage in GC patients. The LN assessments were lower than recommended by the American Joint Cancer Clinician Association in all the three hospitals included in this study. Developing national guidelines, training surgeons and pathologists, conducting regular monitoring and evaluation of the data is necessary to increase NALN and thus improve the staging of GC patients. https://bccr.tums.ac.ir/index.php/bccrj/article/view/263