Early-onset colorectal cancer (EOCRC) is defined as colorectal cancer diagnosed in individuals younger than 50 years old. There is a concept that EOCRC is associated with a worse survival, while the data on literature is conflicting. Evaluation of the available data is highly needed to reach an evidence-based conclusion.
A systematic literature search was performed using Scopus (2015-2020), CENTRAL PubMed (2015-2020) for studies assessed prognosis of EOCRC in comparison with LOCRC using the relative 5-year survival (OS) as a surrogate for prognosis. Extracted information included: study identification, number of EOCRC and LOCRC patients, AJCC stage, and overall 5-year survival. Keywords and Mesh words used: prognosis, outcome, survival, young, early-onset, age of onset, colorectal cancer, rectal cancer, colon cancer. Statistical analysis was done using MedCalc Statistical Software for the meta-analysis.
Meta-analysis for a total of 428554 LOCRC and 670030 EOCRC patients of the included 9 studies showed no statistically significant difference in male ( P= 0.19 ) or female ( P= 0.20 ) as regards the incidence EOCRC when compared to LOCRC. Younger adults were1.2 more likely to present with left-sided and rectal cancer ( OR;1.20, 95% CI, 0.18 to 7.86, P= 0.84 ) than older patients, while the right colon cancer was less presented by 79% in EOCRC patients (OR; 0.79, 95%CI, 0.05 to 11.13, P= 0.86). Stage I disease was statistically significant less diagnosed in EOROC than LOCRC patients ( P< 0.001, 95%CI, 0.31 to 0.70 ), while there were no statistically significant differences for stages II, III, and IV, ( P= 0.27, 95%CI, 0.03 to 2.58), ( P= 0.84, 95%CI, 0.03 to 4.57) and ( P= 0.70, 95%CI, 0.10 to 4.62 ) respectively. There was no difference in the 5 year OS between EOCRC and LOCRC patients ( P= 0.62, 95%CI, -0.004 to 0.002). Subgroup analysis based on the stage showed a better survival in EOCRC patients in all stage groups; ( P= 0.03, 95%CI,1.34 to 21.19) for stage I, (P, 0.001, 95%CI, 2.38 to 3.64) for stage II, (P< 0.001, 95%CI, 2.20 to 4.80) for stage III, and (P= 0.009, 95%CI, 1.62 to 28.79) for stage IV.
EOCRC patients had a similar 5-year OS when compared to LOCRC while had a better 5-year OS when corrected for the disease stage.
The authors.
Quality Control Unit, Faculty of Medicine, Assiut University.
All authors have declared no conflicts of interest.