Key finding
First-degree relative with colorectal cancer associated with 1.87x risk of colorectal cancer (95% CI 1.68–2.09) in a pooled analysis of 46 studies
Evidence & causal status
Moderate
Associational; shared genetics and environment both contribute
Caveats & limitations
Reliability / bias notes: Colorectal-cancer-specific, not all cancer sites; this pooled estimate does not stratify by the relative's age at diagnosis (the under-60 cutoff used in our question could not be verified against a single landmark source)
This describes a population-level association from published research. It is not a prediction about any one individual, and association is not the same as causation unless stated otherwise above.