Old vs new: Risk factors predicting early onset colorectal cancer

Colorectal cancer (CRC) is the second leading cause of all cancer related deaths in the United States and Europe. Although the incidence has been decreasing for individuals' ≥ 50, it has been on the rise for individuals < 50.

To identify potential risk factors for early-onset CRC.

A population-based cohort analysis using a national database, Explorys, screened all patients with an active electronic medical record from January 2012 to December 2016 with a diagnosis of CRC. Subgroups were stratified based on age (25 - 49 years vs ≥ 50 years). Demographics, comorbidities, and symptom profiles were recorded and compared between both age groups. Furthermore, the younger group was also compared with a control group consisting of individuals aged 25-49 years within the same timeframe without a diagnosis of CRC. Twenty-data points for CRC related factors were analyzed to identify potential risk factors specific to early-onset CRC.

A total of 68860 patients were identified with CRC, of which 5710 (8.3%) were younger than 50 years old, with 4140 (73%) between 40-49 years of age. Multivariable analysis was reported using odds ratio (OR) with 95%CI and demonstrated that several factors were associated with an increased risk of CRC in the early-onset group versus the later-onset group. These factors included: African-American race (OR 1.18, 95%CI: 1.09-1.27, P < 0.001), presenting symptoms of abdominal pain (OR 1.82, 95%CI: 1.72-1.92, P <0.001), rectal pain (OR 1.50, 95%CI: 1.28-1.77, P < 0.001), altered bowel function (OR 1.12, 95%CI: 1.05-1.19, P = 0.0005), having a family history of any cancer (OR 1.78, 95%CI: 1.67-1.90, P < 0.001), gastrointestinal (GI) malignancy (OR 2.36, 95%CI: 2.18-2.55, P < 0.001), polyps (OR 1.41, 95%CI: 1.08-1.20, P < 0.001), and obesity (OR 1.14, 95%CI: 1.08-1.20, P < 0.001). Comparing the early-onset cohort versus the control group, factors that were associated with an increased risk of CRC were: male gender (OR 1.34, 95%CI: 1.27-1.41), P < 0.001), Caucasian (OR 1.48, 95%CI: 1.40-1.57, P < 0.001) and African-American race (OR 1.25, 95%CI: 1.17-1.35, P < 0.001), presenting symptoms of abdominal pain (OR 4.73, 95%CI: 4.49-4.98, P < 0.001), rectal pain (OR 7.48, 95%CI: 6.42-8.72, P < 0.001), altered bowel function (OR 5.51, 95%CI: 5.19-5.85, P < 0.001), rectal bleeding (OR 9.83, 95%CI: 9.12-10.6, P < 0.001), weight loss (OR 7.43, 95%CI: 6.77-8.15, P < 0.001), having a family history of cancer (OR 11.66, 95%CI: 10.97-12.39, P < 0.001), GI malignancy (OR 28.67, 95%CI: 26.64-30.86, P < 0.001), polyps (OR 8.15, 95%CI: 6.31-10.52, P < 0.001), tobacco use (OR 2.46, 95%CI: 2.33-2.59, P < 0.001), alcohol use (OR 1.71, 95%CI: 1.62-1.80, P < 0.001), presence of colitis (OR 4.10, 95%CI: 3.79-4.43, P < 0.001), and obesity (OR 2.88, 95%CI: 2.74-3.04, P < 0.001).

Pending further investigation, these potential risk factors should lower the threshold of suspicion for early CRC and potentially be used to optimize guidelines for early screening.