Primary prevention of pancreatic ductal adenocarcinoma (PDAC) relies on modifying lifestyle and metabolic risk factors. No population-level screening test exists for average-risk adults, and most cases are diagnosed at an advanced, incurable stage.^[1][2] Inherited syndromes account for only about 5–10% of unselected cases; the rest reflects ageing, which cannot be modified, plus modifiable exposures.^[1][2] The modifiable factors with the strongest and most consistent evidence are:

• cigarette smoking
• excess adiposity
• dysglycemia and type 2 diabetes mellitus
• heavy alcohol use

Chronic pancreatitis strongly amplifies risk, and is itself partly driven by smoking and alcohol. Smoking cessation is the highest-yield intervention, but its benefit accrues slowly: risk approaches that of never-smokers only after about 15–20 years of abstinence.^[3][4] No drug is recommended for PDAC chemoprevention outside a clinical trial.^[1]

This section covers primary prevention in the general adult population. The screening microchapter covers genetic risk assessment, germline testing, and endoscopic ultrasound/MRI surveillance of high-risk individuals. High-risk individuals include:

• familial pancreatic cancer kindreds
• carriers of BRCA1/2, PALB2 and CDKN2A variants
• people with Peutz-Jeghers syndrome or hereditary pancreatitis

• Cigarette smoking is the leading modifiable risk factor for PDAC. In a meta-analysis of 78 studies, current smokers had a pooled RR of 1.8 compared with never-smokers.^[3][2]
• Risk is dose- and duration-dependent. It rises sharply even at low cigarette counts and plateaus at about 30 cigarettes/day (RR ~2.2) and after about 30 years of smoking.^[3]
• Smoking accounts for about 21% of pancreatic cancer deaths worldwide.^[2] Population-attributable estimates range from about 11% to 32%, depending on local smoking prevalence.^[5][6]
• Cessation lowers risk, but slowly. Former smokers retain a residual RR of about 1.2 compared with never-smokers. Their risk approaches never-smoker levels only after about 15–20 years of abstinence.^[3][4]
• In the Multiethnic Cohort, each year since quitting reduced the excess smoking-related risk by about 9%. The predicted benefit was greatest when cessation occurred before age 65.^[7]
• Clinical action: Ask about tobacco use at every encounter. Offer behavioral counseling combined with pharmacotherapy: nicotine replacement therapy, varenicline, or bupropion.^[8]
• Nicotine replacement therapy is not a demonstrated carcinogen. It should not be withheld because of cancer-risk concerns.^[8]

• Obesity (BMI ≥30 kg/m²) is an independent risk factor. Across 14 cohorts, the pooled RR was about 1.47.^[1]
• Central adiposity carries comparable risk. In UK Biobank, each 1-SD increase in waist-to-hip ratio had an HR of 1.24, compared with 1.20 per 1-SD increase in BMI.^[9]
• The obesity–PDAC association is partly mediated by dysglycemia. Glucose accounted for about 16% of the BMI-associated risk and HbA1c for about 20%.^[9] This supports hyperinsulinemia/IGF-1 signaling and chronic inflammation as plausible mechanisms.
• Clinical action: Counsel patients to:
  • reach and maintain a healthy weight
  • be physically active regularly
  • follow a dietary pattern rich in fruits, vegetables, whole grains, and fiber, while limiting processed and red meat^[1][10]
• Counsel overall dietary patterns rather than specific foods or supplements.

• Diabetes has a dual relationship with PDAC.
  • Long-standing type 2 diabetes (>3 years) is associated with about a 1.5–2.0-fold increased risk.^[1][6]
  • New-onset diabetes in adults ≥50 years can be an early manifestation of occult PDAC. About 0.3–1.0% of such patients are diagnosed with PDAC within 3 years.^[1][6]
• Metabolic syndrome carries an RR of about 1.3, and this attenuates when the syndrome resolves.^[2]
• Clinical action: Optimize glycemic control and cardiometabolic health as part of routine care.
• In adults ≥50 years with unexplained new-onset diabetes, especially with weight loss, maintain a low threshold for pancreatic imaging (see screening).^[6]

• Heavy alcohol use is a modest but real risk factor. A 2025 pooled analysis included 30 prospective cohorts, about 2.49 million participants, and 10,067 cases. Compared with intake of 0.1 to <5 g/day:^[11]
  • 30 to <60 g/day: HR 1.12
  • ≥60 g/day: HR 1.32
  • each 10 g/day increment: about 3% increase in risk
• The associations are most evident at ≥15 g/day in women and ≥30 g/day in men.^[11]
  • Risk is driven by beer and spirits rather than wine.
  • The association holds irrespective of smoking status, which argues against confounding by tobacco alone.^[11][12]
• Heavy intake also raises risk indirectly by causing pancreatitis.
• Light-to-moderate intake shows little or no clear association. International expert panels have regarded the overall alcohol evidence as limited or inconclusive.^[11]
• Clinical action: Advise limiting alcohol. Counsel heavy drinkers toward abstinence or marked reduction; they derive the clearest benefit.

• Chronic pancreatitis markedly elevates PDAC risk. The reported HR is about 7.8, compared with about 3.5 for acute pancreatitis.^[5]
• Much of the acute pancreatitis–PDAC association near diagnosis reflects reverse causation, because tumor-induced ductal obstruction can itself cause pancreatitis.
• Mendelian randomization data do not support acute pancreatitis as causal. Chronic pancreatitis, by contrast, appears causal.^[13]
• Smoking and alcohol are shared drivers of both pancreatitis and PDAC. Stopping both is therefore the principal lever for reducing pancreatitis-mediated risk.^[4][10]

• Certain occupational exposures, such as some pesticides and petrochemicals, have been implicated in PDAC. Workplace exposure reduction is reasonable, although the evidence remains preliminary.^[1][10]

• No drug is recommended for PDAC chemoprevention outside a clinical trial.^[1]
• Aspirin: Observational data are suggestive but inconsistent, and no confirmatory randomized trials exist.
  • A 2026 meta-analysis of 6 cohorts found a pooled HR of 0.80. Heterogeneity was high (I² ~70%) and GRADE certainty was low. In an exploratory subgroup analysis, the HR in patients with diabetes was 0.59.^[14]
  • In a Hong Kong cohort of 343,966 patients with type 2 diabetes, aspirin use was associated with lower PDAC risk (time-dependent aHR 0.58).^[15]
  • In a UK Biobank nested case-control study, the OR for regular aspirin use was 0.80 overall and 0.60 among participants with diabetes.^[16]
  • Bleeding risk must be weighed individually.
• Statins and metformin: Protective associations exist but are hypothesis-generating, inconsistent, and unconfirmed by randomized trials.^[1] For example, statin use had an OR of 0.61 (95% CI 0.43–0.88) in an Italian case-control study.^[17]
• Infections: A 2025 umbrella review identified hepatitis B and hepatitis C co-infection as a risk factor.^[18] However, infections are not validated targets for PDAC prevention.
  • For Helicobacter pylori, overall meta-analytic estimates are non-significant.
  • A strain-specific signal persists for CagA-negative strains.^[19]

1. Screen for and treat tobacco use at every encounter with counseling plus pharmacotherapy. This is the single highest-yield preventive step.^[3][8]
2. Promote healthy weight, regular physical activity, and a high-fiber diet rich in fruits and vegetables, with limited processed and red meat.^[1][10]
3. Optimize glycemic and metabolic health. Evaluate unexplained new-onset diabetes in adults ≥50 years, especially with weight loss, for possible occult PDAC.^[6]
4. Advise limiting alcohol, with abstinence or marked reduction for heavy drinkers.^[11]
5. Do not prescribe aspirin, statins, or metformin solely to prevent PDAC. Base their use on established cardiometabolic indications, and offer clinical-trial participation to high-risk individuals.^[1]

• Low-to-moderate alcohol intake: Associations are weak and regionally inconsistent. In the 2025 pooled analysis, no association was observed in East Asian cohorts.^[11]
• Aspirin, statins, and metformin: Observational data suggest possible protection, but randomized trials have not confirmed it. Any benefit may be concentrated in patients with diabetes.^[14][15][16]
• Early-onset PDAC: Incidence is rising in younger adults. This underscores the need to address smoking, alcohol, obesity, and metabolic dysfunction earlier in life.^[20]

• Do not reassure recent quitters that their risk has already normalized. Residual excess risk persists for 1–2 decades, and the benefit grows with each year quit.^[3][7]
• Do not attribute all diabetes in older adults to type 2 disease. New-onset diabetes after age 50 with weight loss may be a paraneoplastic clue.^[6]
• Reducing heavy alcohol use prevents both pancreatitis and part of the PDAC risk.^[11]
• Avoid recommending specific supplements or “superfoods” for prevention; they lack supporting evidence. Counsel overall dietary patterns instead.^[1]
• Avoid overstating low-dose alcohol risk while underemphasizing the clear risk of heavy drinking.^[11]

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