The Rising Incidence of Younger Patients With Colorectal Cancer: Questions About Screening, Biology, and Treatment

Abstract

Colorectal cancer (CRC) is the third leading cancer diagnosed globally and an important cause of cancer-related mortality. Of interest, while we have witnessed a declining incidence trend over the past few decades in the older population, incidence rates for adolescents and young adults have been increasing steadily. Several factors may well explain this apparent epidemic in the young, namely a lack of routine screening and emerging lifestyle issues such as obesity, lack of exercise, and dietary factors. It is known that both environmental and genetic factors can increase the likelihood of developing CRC. Although inherited susceptibility is associated with the most striking increases in risk, and must always be considered in a young patient with CRC, the majority of CRCs are in fact sporadic rather than familial. Early-onset CRC is a truly heterogeneous disease, with mounting evidence to suggest that this patient population has a distinctive molecular profile, very different to late-onset CRC cases. Currently, both younger and older patients with CRC are treated in essentially the same manner, but with a better understanding of the molecular mechanisms underlying CRC in the young, we will have the opportunity to specifically tailor screening and clinical management strategies in this unique patient population in an effort to improve outcomes. The aim of this review is to outline our current knowledge of the distinguishing features of early-onset CRC, the ongoing research efforts, and the evolving evidence in this field.

Young-onset colorectal cancer in the North East of Scotland: survival, clinico-pathological features and genetics

“…This study also characterised the cohort in terms of clinicopathological features, which found locally advanced rectosigmoid disease to be typical of yCRC. Tumours were commonly located in the left side of the bowel, with a greater proportion of tumours (42.6%) occurring in the rectumconcurring with previous literature describing young-onset disease [7]. Although our cohort is relatively small, it includes all the patients in a geographical area, including both urban & rural populations.…”

“…CRC is the third most common cancer worldwide, with approximately 10% of cases affecting patients aged under 55 years [4,6]. These younger patients often present with more advanced disease and adverse pathological features compared to their older counterparts [7]. This may have a negative impact on their survival outcome [8].…”

Association of Obesity With Risk of Early-Onset Colorectal Cancer Among Women

“…With the emerging evidence that sporadic, young-onset CRC may have distinct molecular features compared to cancers that arise in older individuals (e.g. chromosomal instability, higher prevalence of mucinous or poorly differentiated tumors), 22–26 and the fact that these patients are often detected at a more advanced stage 9 with dramatically greater years of life lost, 27 there is an urgent and unmet public health and clinical need to identify risk factors of young-onset CRC to develop targeted preventive and detection strategies for younger adults with higher risk. 8,28 …”

Rising Proportion of Young Individuals With Rectal and Colon Cancer

“…With the advent of colonoscopy and other screening modalities, an overall declining trend of CRC has been observed, particularly in older populations. 1 However, for unclear reasons, a rise in CRC incidence has been reported in patients aged < 50 years. [1][2][3] Younger patients tend to present with more advanced disease, which may reflect different tumor biology.…”