Consensus checked against original sources: Adiposity and Early-Onset Colorectal Cancer

Cutoff: 13 October 2026. Consensus supports discovery and checks of specific source aspects; it is not a primary study, a full-paper audit or a causal probability meter.

Age threshold and male colon estimate

Consensus cites the pooled European cohort for a55percent male colon-risk increase per five BMI units while discussing a before50 proposition. Original Methods explicitly define early onset as before55 to increase power; Results confirm HR1.55 for male colon cancer, female BMI HR1.03, and weaker rectal associations. The number is correctly attributable to this paper, but it does not directly verify the registered before50 endpoint or a proximal-only causal mechanism. Original PMID41422343. Access: full_text_partial.

Case-control odds versus prospective hazard and age scope

Consensus describes timed BMI-at20 and30 estimates of2.56 and2.06 as hazard-level elevations. The original German study is a retrospective population-based case-control analysis using logistic regression and odds ratios, with cases younger than55 and recalled earlier weight. These estimates are neither prospective hazards nor strictly before50 cancer outcomes. Original PMID34914944. Access: abstract_metadata.

Broader MR versus timed early-onset causal identification

Consensus recognizes that traditional BMI instruments describe lifelong exposure, but its opening asserts that prospective and genetic analyses demonstrate the before50 proposition. Original MR Methods use overall and site-specific CRC outcome consortia without a before50 estimate; IVW and weighted-median positives coexist with heterogeneity and imprecise alternative estimators. This strengthens the broader causal link under assumptions while leaving age and timed-exposure transfer explicit. Original PMID33327948. Access: full_text_partial.

Direct prospective association and effect-size range

Consensus presents obesity associations around1.5-1.9 as consistent prospective evidence. The original NHSII report provides a directly before50 endpoint:114 cancers in85256 women, obesity RR1.93 versus a lean-reference range and a BMI risk gradient. It is an observational female cohort with a linked disclosure correction, not a genetic or randomized exposure experiment and not proof of uniform effects across sex and site. Original PMID30326010. Access: abstract_metadata.

Majority of incidence growth claim

Consensus categorically states adiposity does not explain most incidence growth, largely citing reviews and site patterns. The Korean original computes local BMI-attributable fractions around ten percent under causal assumptions, while its outcome and exposure prevalence are specific to that cohort. This is informative but does not establish a global decomposition or disprove a majority contribution everywhere. The review therefore says a majority-growth claim is unestablished, rather than presenting its negation as proved. Original PMID40971243. Access: abstract_metadata.

Consistency, age interaction and population growth

Consensus emphasizes a consistent adiposity relationship but did not visibly incorporate the requested AllofUs counterpoint. That original found no age-specific BMI effect in a retrospective matched sample. Lack of age interaction is not a zero overall causal effect and does not by itself explain incidence trends; it is retained as a scope and precision boundary. Original PMID42610385. Access: abstract_metadata.

Inherited syndromes versus all susceptibility variants

Consensus gives a broad inherited-syndrome range, mentioning Lynch syndrome. The unselected original finds pathogenic susceptibility variants in16percent of450 cases, spanning Lynch, APC, MUTYH and other genes. These categories must not be collapsed into a Lynch-only percentage or treated as a population attributable fraction for incidence growth. Original PMID27978560. Access: abstract_metadata.

Microbial aspect, mutational timing and provider omissions

Consensus describes microbial/antibiotic exposures as investigational but gives no visible original colibactin source detail in its response. The examined original publisher Methods/Results distinguish historical mutation signatures from current pks-positive bacteria and infer early clonal timing from tumor evolution. This supports a specific organism-genotoxin mechanism more strongly than generic dysbiosis, without establishing universal microbial causation or a directly measured childhood infection date. Original PMID40267983. Access: full_text_partial.

Methods

Consensus was used to identify literature and cross-check specific claims about design, endpoints, scope and research gaps. Those aspects were checked against original primary abstracts/status records and selected original Methods/Results passages. Consensus output was not treated as original full text. Provider search omissions are not evidence that a study does not exist. Source access and examination receipts are retained. Scite use or monthly unavailability is recorded per case; provider citation counts do not change causal grades.