Table 1.
Studies that investigated associations of colorectal cancer with small molecules in plasma or serum from prospective cohorts
| Cohort | Cases/Controls | Follow-upa (y) | Analytical method | Design | Exposure variable | Likely associations | Ref. |
|---|---|---|---|---|---|---|---|
| WHI-OS | 835/835 | 5.2 | LC-MS | Targeted | Choline and its metabolites | TMAO (+); betaine/choline ratio (−) | [26] |
| EPIC [1] | 1367/2323 | 3.7 | LC-MS | Targeted | Methionine and choline metabolites | Methionine, choline, and betaine (−) | [27] |
| EPIC [2] | 95/95 | 14.7 | LC-MS | Targeted | 8 Ultra-long-chain hydroxylated fatty acids | All associations (−) diminished with time to diagnosis (reverse causality) | [22] |
| EPIC [3] | 1238/1238 | 3.8 | Colorimetry and turbidimetry | Targeted | Triglycerides, cholesterol, and lipoproteins | HDL (−) | [19] |
| PLCO | 254/254 | 7.8 | LC-MS and GC-MS | Semi-targeted | 278 Annotated metabolites detected in > 80% of specimens | Glycochenodeoxycholate (+) in women but not men | [25] |
WHI-OS Women’s Health Initiative Observational Study, EPIC European Prospective Investigation into Cancer, GC-MS gas chromatography-mass spectrometry, HDL high-density lipoprotein cholesterol, LC-MS liquid chromatography-mass spectrometry, PLCO Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, TMAO trimethylamine-N-oxide, WHI-OS Women’s Health Initiative-Observational Study, (+) positively associated with CRC, (−) negatively associated with CRC
aMean period of follow-up