P3867 - Alarming Increase in Late-Stage Early Onset Colorectal Cancer Incidence in the United States in Different Anatomical Locations

Yazan Abboud, MD¹, Eric Montminy, MD², Anand Shah, MD¹, Chun-Wei Pan, MD³, Kaveh Hajifathalian, MD¹, Paul Gaglio, MD⁴, Ahmed Al-Khazraji, MD^1
1Rutgers New Jersey Medical School, Newark, NJ; ²Center for Endoscopic Research and Therapeutics (CERT), University of Chicago, Chicago, IL; ³John H. Stroger, Jr. Hospital of Cook County, Chicago, IL; ⁴Rutgers NJ Medical School, Newark, NJ

Introduction: Early Onset Colorectal Cancer (EO-CRC) is more common in proximal colon due to increased tendency for symptomatic presentation. With the shift toward screening adults at younger ages, improvement in detection of early-stage CRC is expected. To assess this hypothesis, we conducted an analysis of EO-CRC incidence categorized by tumor anatomical location and stage at diagnosis.

Methods: EO-CRC age-adjusted incidence rates in adults aged 20-54 years between 2001-2020 were calculated from the United States Cancer Statistics database (covers 98% of US population). The rates were categorized by location into 1: cecum, ascending colon, and hepatic flexure, 2: transverse colon, 3: splenic flexure and descending colon, and 4: sigmoid colon, rectosigmoid junction, and rectum. Stages at diagnosis were early (localized and in situ) and late (regional and distant). Annual percentage change (APC) and average APC (AAPC) were estimated using joinpoint regression and weighted Bayesian Information Criteria (P< 0.05).

Results: 514,875 patients were diagnosed with EO-CRC between 2001-2020 (proximal tumors composed 63.7%). Incidence rates increased in all locations except the cecum, ascending colon, and hepatic flexure which had decreasing trend (AAPC= -0.45, P=0.04) (Figure).

In early-stage tumors, incidence initially increased in the first decade followed by a decrease. On average, the incidence was stable in all locations except transverse colon which had increasing trend (AAPC= 1.06, P=0.01) (Table).

In late-stage tumors, incidence increased in all locations during the second decade of our study. The greatest increase was in the sigmoid, rectosigmoid, and rectum (187,136 patients; APC= 3.19, P< 0.001), followed by transverse colon (16,457 patients, APC= 2.98, P< 0.001), splenic flexure and descending colon (23,021 patients; APC= 2.03, P=0.001), and lastly cecum, ascending colon, and hepatic flexure (71,253 patients; APC= 0.53, P=0.03).

Discussion: EO-CRC incidence increased in the US over the past two decades in all anatomical locations except right-sided lesions. While incidence of early-stage tumors decreased in recent years, an alarming increase in late-stage tumors was noted over the past decade, most pronounced in proximal tumors. Our findings prompt considerations regarding the adequacy and timeliness of current screening recommendations. Further research is warranted to investigate contributions to the delayed diagnosis of EO-CRC, including disparities in healthcare access or emerging risk factors.



Disclosures:


Yazan Abboud, MD¹, Eric Montminy, MD², Anand Shah, MD¹, Chun-Wei Pan, MD³, Kaveh Hajifathalian, MD¹, Paul Gaglio, MD⁴, Ahmed Al-Khazraji, MD¹. P3867 - Alarming Increase in Late-Stage Early Onset Colorectal Cancer Incidence in the United States in Different Anatomical Locations, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.