Longevity & Aging · Metabolic & Cardiometabolic
chronic hyperinsulinemia increases risk of breast/colon/pancreatic/endometrial cancer
In plain terms: Does chronically high insulin raise cancer risk?
Strong support Longevity & Aging 🔬 Includes disconfirming
Part of: • Insulin & Metabolic Aging
RefutedContestedStrong support
consensus score 0.61
Yes for endometrial and colorectal cancer the association is robust, weaker/age-restricted for postmenopausal breast, and mixed for pancreatic, so the association is real but varies by cancer type.
📅 Last reviewed: 2026-07-14 ⓘ
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: All trials, pooled (Meta-analysis)
MechanismIn-vitroAnimalObservationalRCTMeta-analysis
How the studies fall
13 support 1 contradict 2 tested null 3 mixed · 19 sources, 14 independent groups
What the evidence shows
Chronically high insulin is associated with higher cancer risk, most robustly for endometrial and colorectal cancer, where Mendelian randomisation supports causality and pooled studies link HOMA-IR and C-peptide to colorectal risk. Breast and pancreatic are weaker and mixed, reverse causation complicates pancreatic, and one East Asian analysis disagreed.
The evidence (20)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Fabiani R, Squadroni V, Rosignoli P 2026 · J Pers Med | meta-analysis | mixed | moderate | Meta-analysis of 26 studies: higher triglyceride-glucose (TyG) index (insulin resistance marker) associated with increased cancer risk (categorical OR 1.33, 95% CI 1.22-1.45; continuous OR 1.14, 95% CI 1.10-1.19), strongest for GI |
| Hazelwood E, Sanderson E, Tan VY, Ruth KS, Frayling TM, Dimou N, Gunter MJ, Dossus L, Newton C, Ryan N, Pournaras DJ, O'Mara TA, Davey Smith G, Martin RM, Yarmolinsky J 2022 · BMC Med | observational | supports | high | Multivariable Mendelian randomization found genetically higher fasting insulin causally increases endometrial cancer risk and mediates part of the BMI effect. |
| Li L, Li F, Pan Z 2025 · Cancer Cell Int | observational | tested-null | low | East Asian two-sample MR found T2D genetically associated with LOWER risk of most cancers including endometrial/colorectal/breast, a disconfirming signal likely reflecting collider bias in Asian T2D GWAS. |
| Xu J, Ye Y, Wu H, Duerksen-Hughes P, Zhang H, Li P, Huang J, Yang J, Wu Y, Xia D 2016 · BMJ Open | meta-analysis | supports | moderate | Meta-analysis found fasting insulin, HOMA-IR and C-peptide each significantly associated with increased colorectal cancer risk. |
| Grote VA, Rohrmann S, Nieters A, Dossus L, Tjønneland A, Halkjær J, Overvad K, Fagherazzi G, Boutron-Ruault MC, Morois S, Teucher B, Becker S, Sluik D, Boeing H, Trichopoulou A, Lagiou P, Trichopoulos D, Palli D, Pala V, Tumino R, Vineis P, Panico S, Rodríguez L, Duell EJ, Molina-Montes E, Dorronsoro M, Huerta JM, Ardanaz E, Jeurnink SM, Beulens JW, Peeters PH, Sund M, Ye W, Lindkvist B, Johansen D, Khaw KT, Wareham N, Allen N, Crowe F, Jenab M, Romieu I, Michaud DS, Riboli E, Romaguera D, Bueno-de-Mesquita HB, Kaaks R 2011 · Diabetologia | observational | mixed | moderate | EPIC found pancreatic cancer risk related to diabetes/glycemia but C-peptide associations were weak and complicated by reverse causation from the tumor. |
| Yang C, Xing B, Zhang Z, Jia Y, Peng L 2026 · Medicine | observational | supports | low | Two-sample MR found genetically higher IGF-1 causally associated with increased colorectal (OR 1.22) and esophageal cancer risk. |
| Karmali R, Dalovisio A, Borgia JA, Venugopal P, Kim BW, Grant-Szymanski K, Hari P, Lazarus H 2015 · Blood Rev | mechanism | supports | moderate | Review details dysregulated insulin/IGF-1 signaling activating PI3K/Akt/mTOR and RAS/MAPK mitogenic pathways linking metabolic syndrome to malignancy. |
| Gaudet MM, Patel AV, Teras LR, Sun J, Campbell PT, Stevens VL, Jacobs EJ, Gapstur SM 2013 · Cancer Causes Control | observational | supports | moderate | CPS-II nested case-control: high C-peptide associated with postmenopausal breast cancer (T3 vs T1 OR 1.63, 1.08-2.45), attenuated after BMI adjustment. |
| Huang W, Jin X 2026 · Medicine (Baltimore) | observational | tested-null | low | NHANES 2011-2018 cross-sectional study (n=8116 women): higher Body Roundness Index associated with 14% higher odds of gynecological cancer (OR 1.14) and highest quartile 1.71-fold greater odds; adiposity indices, not insulin direc |
| Autier P, Koechlin A, Boniol M, Mullie P, Bolli G, Rosenstock J, Boyle P 2013 · Cancer Causes Control | meta-analysis | contradicts | moderate | MA of prospective studies, BREAST cancer only (insulin: 6 articles, 1,890 cases; C-peptide: 5 articles, 1,759 cases), highest vs lowest quantile: 'SRR and 95 % CI were 1.08 (0.66-1.78) for insulin and 1.04 (0.77-1.41) for C-peptide.' 'Restricting the analysis to women diagnosed with breast cancer before or after menopause did not alter results.' A null on this directional claim, so contradicts; high heterogeneity for insulin. |
| Jenab M, Riboli E, Cleveland RJ, Norat T, Rinaldi S, Nieters A, Biessy C, Tjønneland A, Olsen A, Overvad K, Grønbaek H, Clavel-Chapelon F, Boutron-Ruault MC, Linseisen J, Boeing H, Pischon T, Trichopoulos D, Oikonomou E, Trichopoulou A, Panico S, Vineis P, Berrino F, Tumino R, Masala G, Peters PH, van Gils CH, Bueno-de-Mesquita HB, Ocké MC, Lund E, Mendez MA, Tormo MJ, Barricarte A, Martínez-García C, Dorronsoro M, Quirós JR, Hallmans G, Palmqvist R, Berglund G, Manjer J, Key T, Allen NE, Bingham S, Khaw KT, Cust A, Kaaks R 2007 · Int J Cancer | observational | supports | high | EPIC nested case-control (1,078 cases): highest vs lowest C-peptide quintile OR 1.56 (1.16-2.09) for colorectal cancer, stronger for colon. |
| Verheus M, Peeters PH, Rinaldi S, Dossus L, Biessy C, Olsen A, Tjønneland A, Overvad K, Jeppesen M, Clavel-Chapelon F, Téhard B, Nagel G, Linseisen J, Boeing H, Lahmann PH, Arvaniti A, Psaltopoulou T, Trichopoulou A, Palli D, Tumino R, Panico S, Sacerdote C, Sieri S, van Gils CH, Bueno-de-Mesquita BH, González CA, Ardanaz E, Larranaga N, Garcia CM, Navarro C, Quirós JR, Key T, Allen N, Bingham S, Khaw KT, Slimani N, Riboli E, Kaaks R 2006 · Cancer Epidemiol Biomarkers Prev | observational | mixed | moderate | EPIC found no overall C-peptide-breast cancer association; elevated risk only in nonfasting women over 60 (OR 2.03), so hyperinsulinemia link is age/postmenopausal-restricted. |
| Cust AE, Allen NE, Rinaldi S, Dossus L, Friedenreich C, Olsen A, Tjønneland A, Overvad K, Clavel-Chapelon F, Boutron-Ruault MC, Linseisen J, Chang-Claude J, Boeing H, Schulz M, Benetou V, Trichopoulou A, Trichopoulos D, Palli D, Berrino F, Tumino R, Mattiello A, Vineis P, Quirós JR, Agudo A, Sánchez MJ, Larrañaga N, Navarro C, Ardanaz E, Bueno-de-Mesquita HB, Peeters PH, van Gils CH, Bingham S, Khaw KT, Key T, Slimani N, Riboli E, Kaaks R 2007 · Int J Cancer | observational | supports | moderate | EPIC: top vs bottom C-peptide quartile RR 2.13 (1.33-3.41) for endometrial cancer, attenuated to 1.56 after BMI adjustment. |
| Yoon YS, Keum N, Zhang X, Cho E, Giovannucci EL 2015 · Metabolism | meta-analysis | supports | moderate | Meta-analysis linked hyperinsulinemia/insulin resistance markers to increased risk of colorectal adenoma, the CRC precursor. |
| Wolpin BM, Bao Y, Qian ZR, Wu C, Kraft P, Ogino S, Stampfer MJ, Sato K, Ma J, Buring JE, Sesso HD, Lee IM, Gaziano JM, McTiernan A, Phillips LS, Cochrane BB, Pollak MN, Manson JE, Giovannucci EL, Fuchs CS 2013 · J Natl Cancer Inst | observational | supports | high | Pooled prospective cohorts: higher prediagnostic insulin and proinsulin associated with increased pancreatic cancer risk. |
| Dashti SG, English DR, Simpson JA, Karahalios A, Moreno-Betancur M, Biessy C, Rinaldi S, Ferrari P, Tjønneland A, Halkjær J, Dahm CC, Vistisen HT, Menegaux F, Perduca V, Severi G, Aleksandrova K, Schulze MB, Masala G, Sieri S, Tumino R, Macciotta A, Panico S, Hiensch AE, May AM, Quirós JR, Agudo A, Sánchez MJ, Amiano P, Colorado-Yohar S, Ardanaz E, Allen NE, Weiderpass E, Fortner RT, Christakoudi S, Tsilidis KK, Riboli E, Kaaks R, Gunter MJ, Viallon V, Dossus L 2021 · Cancer Epidemiol Biomarkers Prev | observational | supports | high | EPIC causal mediation analysis identified C-peptide (hyperinsulinemia) as a mediator of the adiposity-endometrial cancer link in postmenopausal women. |
| Ghadirzadeh B, Nejati Z, Moradveisi B, Moradi Y 2026 · Acta Diabetol | meta-analysis | supports | high | Updated meta-analysis (35 studies) found diabetes associated with endometrial cancer, pooled RR 1.64 (1.50-1.80), independent of adiposity. |
| Rinaldi S, Cleveland R, Norat T, Biessy C, Rohrmann S, Linseisen J, Boeing H, Pischon T, Panico S, Agnoli C, Palli D, Tumino R, Vineis P, Peeters PH, van Gils CH, Bueno-de-Mesquita BH, Vrieling A, Allen NE, Roddam A, Bingham S, Khaw KT, Manjer J, Borgquist S, Dumeaux V, Torhild Gram I, Lund E, Trichopoulou A, Makrygiannis G, Benetou V, Molina E, Donate Suárez I, Barricarte Gurrea A, Gonzalez CA, Tormo MJ, Altzibar JM, Olsen A, Tjonneland A, Grønbaek H, Overvad K, Clavel-Chapelon F, Boutron-Ruault MC, Morois S, Slimani N, Boffetta P, Jenab M, Riboli E, Kaaks R 2010 · Int J Cancer | meta-analysis | supports | moderate | EPIC plus meta-analysis of 10 prospective studies found a modest positive association of serum IGF-I with colorectal cancer (RR 1.07 per SD). |
| Simpson A, Petnga W, Macaulay VM, Weyer-Czernilofsky U, Bogenrieder T 2017 · Target Oncol | mechanism | supports | moderate | Review documents insulin/IGF-1R and INSR-A signaling driving proliferative/anti-apoptotic (mitogenic) pathways, the mechanistic basis for hyperinsulinemia promoting cancer. |
| Chen S, Jiang F, Wang J, Li J, Tan W, Ren J, Zhang M, Feng D 2026 · World J Urol | observational | supports | moderate | UK Biobank cohort (n=410,766, 13.65y follow-up): each 1-SD increase in insulin-resistance score (METS-IR) associated with 26% higher renal cell carcinoma risk (HR 1.26, 95% CI 1.12-1.43); combined high METS-IR+inflammation HR 2.40 |
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