Colorectal cancer in adolescents and young adults: Defining a growing threat

Abstract

Colorectal cancer (CRC) incidence is rising among adolescents and young adults (AYAs), with the greatest increase occurring in distal colon and rectal cancers. Reasons for this striking trend are not well understood. Genetically linked cases of CRC occur in the context of familial conditions such as Lynch Syndrome, but most AYA cases of CRC are sporadic. Unique biology is suggested, yet limited information is available regarding the molecular underpinnings of CRC in this age group. Young patients are more likely to experience delays in diagnosis and to present with advanced-stage disease; yet, prognosis by stage is comparable between younger and older adults. Treatment paradigms are based on evidence reflecting the older adult population. Given the concerning rise in CRC rates among AYAs, there is urgent need for further research into the role of screening from a younger age, biology of disease, and optimal therapies in this age group. K E Y W O R D S adolescents, colorectal neoplasm, young adults 1 INTRODUCTION Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer deaths in the United States. 1 CRC largely remains a disease of older adults with only a minority of cases diagnosed in adolescents and young adults (AYAs), aged 15-39 years. While effective screening has contributed to reduced incidence and mortality from CRC in recent decades, young-onset CRC is on the rise. 2 CRC linked to familial syndromes is more common among AYAs, yet the vast majority of cases in this age group are sporadic. 3 A full understanding of drivers of CRC in this age group is lacking; however, age-based disparities relating to CRC have been a focus of recent literature. Epidemiology, risk factors, biology, prognosis, clinical management, and unique considerations for CRC in AYAs will be reviewed here.

Sporadic colorectal cancer in adolescents and young adults: a scoping review of a growing healthcare concern

“…Although the absolute incidence of colon and rectal cancers in young adults ≤ 49 years of age is low overall, a change in epidemiology with a significant rise in incidence has been clearly documented in the literature [3,5,29]. A recently published systematic review by Saad El Din et al, assessing population trends of CRC in AYAs, highlights the increasing risk of CRC in this patient cohort, largely driven by rectal cancers [29].…”

“…As highlighted by Weinberg et al, most young patients with CRC have sporadic disease, and only a small proportion of patients with familial CRC have an identifiable hereditary syndrome [5,19]. Family history is recognised as a potential risk factor in 42.9% (n = 3) of the included studies.…”

“…Although CRC still remains a disease of older adults, incidence has been increasing in recent years amongst adolescents and young adults (AYAs) aged ≤ 49 years old [3,4]. Although CRC linked to familial syndromes is more common in AYAs, the majority of cases in this age group are sporadic [5]. This patient group tends to have a delayed diagnosis and more advanced disease at presentation [3,6,7].…”

NCCN Guidelines Insights: Colorectal Cancer Screening, Version 2.2020

“…The NCCN Guidelines Insights do not represent the full NCCN Guidelines; further, the National Comprehensive Cancer Network ® (NCCN ® ) makes no representations or warranties of any kind regarding their content, use, or application of the NCCN Guidelines and NCCN Guidelines Insights and disclaims any responsibility for their application or use in any way. 1 Duke Cancer Institute; 2 Vanderbilt-Ingram Cancer Center; 3 Yale Cancer Center/Smilow Cancer Hospital; 4 University of Wisconsin Carbone Cancer Center; 5 UC San Diego Moores Cancer Center; 6 Case Comprehensive Cancer Center/University Hospitals Seidman Cancer Center and Cleveland Clinic Taussig Cancer Institute; 7 Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine; 8 Moffitt Cancer Center; 9 The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins; 10 Roswell Park Comprehensive Cancer Center; 11 Mayo Clinic Cancer Center; 12 Robert H. Lurie Comprehensive Cancer Center of Northwestern University; 13 Fred Hutchinson Cancer Center/Seattle Cancer Care Alliance; 14 Fox Chase Cancer Center; 15 Huntsman Cancer Institute at the University of Utah; 16 City of Hope National Medical Center; 17 Fred & Pamela Buffett Cancer Center; 18 University of Michigan Rogel Cancer Center; 19 Memorial Sloan Kettering Cancer Center; 20 UCLA Jonsson Comprehensive Cancer Center; 21 Dana-Farber/Brigham and Women's Cancer Center | Massachusetts General Hospital Cancer Center; 22 Abramson Cancer Center at the University of Pennsylvania; 23 University of Colorado Cancer Center; 24 O'Neal Comprehensive Cancer Center at UAB; 25 The Ohio State University Comprehensive Cancer Center -James Cancer Hospital and Solove Research Institute; 26 UCSF Helen Diller Family Comprehensive Cancer Center; and 27 National Comprehensive Cancer Network.…”

“…3,14 In general, most CRC cases in adolescent and young adult individuals appear to be sporadic. 15 Causes for this increase in early-onset CRC are unknown and may be attributable to diet and other lifestyle factors. 3 These NCCN Guidelines Insights focus on recent additions to the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines), including a section on primary and secondary CRC prevention, and provide a summary of the panel's discussion of relevant data related to the age at which to initiate screening in average-risk individuals and the follow-up of low-risk adenomas after an initial colonoscopy, with concluding statements on specific changes made to the Guidelines.…”