Medical Journal of the Islamic Republic Of Iran

en Factors Affecting the Survival Rate of Patients with Left and Right-Sided Colon Cancers Biostatistics and Epidemiology Biostatistics and Epidemiology Original Research Original Research     Background: Studies show that right-sided colon cancer (RCC) is more likely to be fatal than left-sided colon cancer (LCC). This study aimed to compare survival rates and characteristics of both types. In addition, this study focused on evaluating the diagnosis of colon cancer during the COVID-19 pandemic.    Methods: This is a retrospective cohort study that examined 582 patients treated for left and right colon cancer from March 2012 to March 2013 in Kerman province. Data were collected from a retrospective cohort, and the outcome was death due to colon cancer. The effect of tumor location on survival was evaluated using Cox regression analysis. The impact of the coronavirus disease 2019 (COVID-19) pandemic on the trend of the number of colon cancer patients was analyzed using time series models.    Results: The overall 5-year survival of patients was equal to 62.6% and the mean age was 59.94 ± 15.06 years. The 5-year survival rate of the tumor location on the right side was 59.5% and on the left side was 65.6%. The risk of death from RCC was 53.6% higher than from LCC. The hazard ratio (HR) from RCC compared with LCC was higher in older patients (HR, 1.402; 95% CI, 1.001-1.976), urban areas (HR, 1.608; 95% CI, 1.158-2.235), adenocarcinoma (HR, 1.703; 95% CI, 1.254-2.312), well-differentiated (HR, 2.325; 95% CI, 1.001-5.401), and moderately differentiated tumor grade (HR, 1.421; 95% CI, 1.002-2.016). The expected number of colon cancers during the COVID-19 pandemic was 3.5, 2, and 1.9 times the identified cases in the first 3, 6, and 12 months of the COVID-19 pandemic.    Conclusion: The risk of death for RCC was higher than for LCC, and the risk of death from RCC was higher in older adults, urban areas, adenocarcinoma, and well-differentiated and moderately differentiated tumor grades than the risk of death from LCC. In addition, the COVID-19 pandemic led to a decline in colon cancer diagnoses.   Left-sided Colon Cancer, Right-sided Colon Cancer, Survival, Trend, Covid-19, Impact 862 868 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-8618-1&slc_lang=en&sid=1 Farshid Sharifi sharififarshid2018@gmail.com 200319475328460089627 200319475328460089627 No Modeling in Health Research Center, Institute for Futures Studies in Health, Kerman University of Medical Sciences, Kerman, Iran Reza Malekpour Afshar r.malekpourafshar@gmail.com 200319475328460089628 200319475328460089628 No Pathology and Stem Cell Research Center, Kerman University of Medical Sciences, Kerman, Iran Azam Bazrafshan Bazrafshan.a.83@gmail.com 200319475328460089629 200319475328460089629 No HIV/STI Surveillance Research Center, and WHO Collaborating Center for HIV Surveillance, Institute for Futures Studies in Health, Kerman University of Medical Sciences, Kerman, Iran Ashraf Yazdizadeh yazdi.a9889@yahoo.com 200319475328460089630 200319475328460089630 No Deputy of Health, Kerman University of Medical Sciences, Kerman, Iran Moghaddameh Mirzaee m_mirzaee@kmu.ac.ir 200319475328460089631 200319475328460089631 Yes Modeling in Health Research Center, Institute for Futures Studies in Health, Kerman University of Medical Sciences, Kerman, Iran