Per- and poly-fluoroalkyl substances exposure and risk of gastrointestinal cancers: a systematic review and meta-analysis
Bibliographic record
Abstract
BACKGROUND: Per- and poly-fluoroalkyl substances (PFASs) are a group of synthetic chemicals used since the 1940s in industrial and consumer applications. These substances are known or suspected to cause cancer, particularly kidney and testicular cancer. However, their association with other types of cancer is not well understood. This review aims to investigate the link between PFAS exposure and the risks of other cancers, including gastrointestinal cancers such as esophageal, gastric, colorectal, and pancreatic cancer. METHODS: We conducted a systematic review of literature from the International Agency for Research on Cancer Monographs, Agency for Toxic Substances and Disease Registry documents, and PubMed (up to January 2024) focusing on the association between PFAS exposure and gastrointestinal cancers. Four independent reviewers screened the studies, extracted the information, and evaluated the quality of the studies using a modified Newcastle-Ottawa Scale. Meta-analyses were performed with random-effects models, including stratified analyses and dose-response assessments. RESULTS: The meta-analysis included 17 studies. The summary relative risks (RR) of esophageal cancer for perfluorooctanoic acid (PFOA) exposure was 0.75 (95% confidence interval [CI], 0.35-1.60; n = 2), and for perfluorooctane sulfonic acid (PFOS) was 1.76 (95% CI, 0.32-9.68; n = 1). The RR for gastric cancer and PFOA was 0.59 (95% CI, 0.28-1.21; n = 2) and PFAS was 0.96 (95% CI, 0.83-1.12; n = 2). The RR for colorectal cancer and PFOA was 0.83 (95% CI, 0.65-1.06; n = 6) and PFOS was 0.71 (95% CI, 0.22-2.27; n = 4). The RR for pancreatic cancer was 1.02 (95% CI, 0.90-1.15; n = 9) and PFOS was 0.92 (95% CI, 0.76-1.11; n = 2). Stratified analyses by geographical region, study design, quality score, year of publication, gender, and outcome revealed no associations for colorectal and pancreatic cancers. No dose-response trends were identified. Publication bias was suggested for gastric cancer. CONCLUSION: Our study suggested no association between PFAS exposure and esophageal, gastric, colorectal, or pancreatic cancer. More rigorous research is needed to investigate this relationship in different settings, with precise PFAS quantification, a wider range of compounds, larger sample sizes for specific cancers, and better control for potential confounders. Our meta-analysis suggests inconclusive evidence, highlighting the need for further research.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.011 | 0.028 |
| Meta-epidemiology (narrow) | 0.003 | 0.002 |
| Meta-epidemiology (broad) | 0.017 | 0.038 |
| Bibliometrics | 0.007 | 0.009 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.004 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".