Early Onset Colorectal Cancer

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths globally, with increasing incidence rates. While predominantly affecting older adults, CRC cases among individuals under 50 (early-onset CRC, or EoCRC) are rising. This age group rarely undergoes routine screening, resulting in delayed diagnoses and more advanced disease at presentation. In the USA, EoCRC accounts for 10% of CRC cases and is the leading cause of cancer-related deaths in men under 50. Despite the increase in EoCRC incidence, the causes remain unclear. Only 25% of cases have a CRC family history, suggesting environmental factors. Diets low in fibre and rich in fat and red meat, obesity, alcohol consumption, sedentary lifestyle, stress, and chronic inflammation of the GI tract are estimated to account for 70-90% of CRC risk. According to the World Cancer Research Fund, 47% of all CRC cases could be prevented through lifestyle changes, particularly in diet and physical activity. These lifestyle factors are also strongly linked to changes in the gut microbiome, which differs markedly between CRC patients and healthy individuals. The microbiome may influence tumour development by producing metabolites that regulate immune responses or create anti-tumour environments. Thus, the gut microbiome is a promising target for early CRC detection and prevention. This study aims to develop a non-invasive, microbiome-based diagnostic tool for CRC, identifying biomarkers to improve early detection, personalise treatment, and reduce healthcare costs.

An increase in early-onset colorectal cancers (eoCRC), defined as a CRC before 50 years, is confirmed globally. CRC pathogenesis has been associated with several risk factors (family history, germline pathogenic variants, obesity, alcohol, physical activity, red meat, and a Western diet). Design: an international, multicenter, retrospective case-control study of prospectively enrolled patients; low-risk intervention study as it will perform a fecal occult blood test Endpoint: predictive power of a semi-quantitative food frequency questionnaire (SQFFQ) developed for eoCRC. Cases: Patients with a recent diagnosis of eoCRC (within 2 years from enrollment). Controls: matched by age (matching range ± 5 years) and sex. Healthy volunteers will be mainly enrolled among workers within the participating hospital center. The enrolled healthy volunteers will perform a fecal occult blood test. Variables of interest: age, sex, ethnicity, BMI at the time of eoCRC diagnosis and at 18 years old, country, tobacco smoking at the time of eoCRC diagnosis and at 18 years old, sitting time, TV-viewing time, moderate-to-vigorous physical activity (MVPA), waist circumference (cm), home blood pressure levels (mmHg), fasting blood glucose (mg/dl), regular consumption of aspirin/NSAID, calcium and folate supplements, oral contraceptive agents, post-menopausal hormones and years of consumptions, if the filled questionnaire reflects diet for the last 5-10 years before. Cases only: date of eoCRC diagnosis, symptoms at diagnosis, eoCRC localization, eoCRC stage, histological diagnosis, type of surgery, and date (if performed), chemotherapy and radiotherapy (if performed), vital status and duration of follow-up, family history of CRC and other cancers (uterus, ovary, stomach, small intestine, urinary tract/bladder/kidney, bile ducts, brain, pancreas, skin tumors), type of germline pathogenetic variant (if performed). Before the case-control study, three non-consecutive 24-hour Dietary Recalls (24hDRs) will validate the SQFFQ. The SQFFQ will be administered to the validation study group during three non-consecutive calls, including one non-weekday (30-minute 24-h-recall computer-aided personal interview). Primary Objective To measure the relative risk of specific dietary and lifestyle factors (smoking habit, alcohol intake, physical activity) for early-onset colorectal cancer in countries where eoCRC incidence is increasing versus stable/decreasing

The study aims to collect high quality clinical data on lifestyle and patient biomaterials prior to start or during / after treatment of early-onset colorectal cancer (EOCRC) and to inform on treatment and survival outcomes of EOCRC patients.