Trends of colorectal cancer and associated factors in the United States: A SEER registry analysis.

Abstract

e15553 Background: Colorectal cancer (CRC) is the fourth most common type of cancer diagnosed in the US, accounting for 8% of new cancers diagnosis in 2022. Despite advancements in the screening and diagnostic methods, CRC still contributes significantly to cancer-related healthcare burden ($24.3 billion/year). Several factors including wider demographic reach, socioeconomic equity, age at screening, CRC awareness, and social media platforms have contributed to this changing landscape. We conducted a Surveillance, Epidemiology, and End Results Program (SEER) based analysis to determine the trends of CRC diagnosis and potential risk factors. Methods: Individual data was acquired from SEER 9 registry from 1975-2018. R was used for the statistical analyses. Univariate logistic regression was performed to evaluate the relation between year of diagnosis and each variable (year of diagnosis, household income, household location, sex, and race) at the time of diagnosis. Multivariate regression was performed for individuals in all age group and less than 45 years of age. P-value less than 0.05 was considered significant. Results: In total 550,221 CRC patients were retrieved. 91.7% (504,709) were ≥50 years and 4.5% (24,674) were < 45. Over the years, there was a notable increase in percentage of patients with age < 45 years amongst all CRC patients (3.3% in 1975-1979 vs. 7.4% in 2015-2018) with females increasing faster than males. A remarkable drop in percentage of CRC case in individuals ≥50 years amongst all gastrointestinal cancers (63.0% in 1975-1979 vs. 44.8% in 2015-2018) with females decreasing faster than males. There were no interactions between the year of diagnosis and above variables. Multivariate logistic regression exhibited lower odds of CRC diagnosis in all non-white races and males, but higher odds in lower household income and non-metropolitan areas (Table 1). Subgroup analysis of age group < 45 years pertained similar odds. Conclusions: The striking drop in number of CRC cases above 50 years of age can be attributed to earlier detection with screening methods, and other socioeconomic factors like healthcare literacy and awareness. Increased representation of younger population over the years reaffirms the recent change in guidelines for screening. Further studies focusing on determining the impact in outcomes of screening methods in younger population and equality of implementation in disadvantaged population are highly warranted. [Table: see text]