Cancer Prevention: What the Latest Evidence Actually Supports (2026)

Here is the single most useful sentence in all of cancer epidemiology:

Up to 42% of cancer cases in US adults are attributable to modifiable risk factors. The other 58% is, broadly speaking, biology and bad luck.

That number comes from Islami et al., published in CA: A Cancer Journal for Clinicians in 2018 (PMID 29160902), and it remains the most rigorous population-attributable-fraction analysis of modifiable cancer risk in a developed country. Forty-two percent of incident cancers. Forty-five percent of cancer deaths. Not a motivational statistic — an actuarial one.

That framing matters because the wellness and longevity industry has a bad habit around cancer. One side sells dread ("everything causes cancer"). The other side sells false control ("take this compound and you won't get it"). Both are wrong, and both are corrosive. The real picture is narrower, harder, and more useful: a handful of behaviors and medical interventions have very strong evidence, most "cancer-fighting" supplements have failed their randomized trials, and a significant fraction of cancer will happen regardless of what you do — because cancer is fundamentally a disease of cell division, and every cell division carries a small error rate.

This article walks through what the data actually says in 2026. Where the evidence is strong, we'll say so. Where it's weak, we'll say that too. No product pitches. No promises.

TL;DR — Key Takeaways

• ~42% of US cancers are attributable to modifiable risk factors (Islami et al. 2018, PMID 29160902); the largest is cigarette smoking at 19% of cases and 29% of deaths.
• Ranking of modifiable risks by US attributable fraction: smoking (19%) >> excess body weight (7.8%) > alcohol (5.6%) > UV radiation (4.7%) > physical inactivity (2.9%) > poor diet (~3% combined) > infections (HPV, HepB, H. pylori).
• The 2018 WCRF/AICR report identifies body fatness as a convincing cause of 12 cancers and alcohol as a convincing cause of 7.
• Screening with proven mortality benefit: low-dose CT for high-risk smokers (NLST, PMID 21714641), colonoscopy/FIT for colorectal (NordICC, PMID 36214590), mammography ages 40–74, HPV testing for cervical, PSA (individualized) for prostate.
• Vaccines that prevent cancer: HPV vaccine cuts invasive cervical cancer ~88% when given before age 17 (Lei et al. NEJM 2020, PMID 32997908); hepatitis B vaccine has reduced childhood liver cancer ~80% in vaccinated cohorts.
• Failed in RCTs: beta-carotene (ATBC, CARET — actually increased lung cancer in smokers), vitamin E + selenium (SELECT), high-dose vitamin D (VITAL), most antioxidant megadoses.
• Mostly unproven despite popularity: curcumin, green tea extract, resveratrol, most "anti-cancer" botanicals for primary prevention in humans.
• The honest summary: don't smoke, stay lean, move, drink less, get screened on schedule, get vaccinated. That is almost all of the actionable evidence.

Part 1 — The 42% That's Preventable

The definitive US estimate comes from Islami and colleagues at the American Cancer Society, who applied population attributable fraction (PAF — the percentage of disease that would disappear if a given risk factor were removed from the population) to 26 cancer types using national risk-factor prevalence data and relative-risk estimates from the published literature.

Their headline numbers, for US adults 30 and older:

A few observations before we go further.

First, smoking dwarfs everything else. It is the single most important public-health intervention in cancer prevention, full stop. If you are a current smoker and you do one thing on this list, quit. The benefits begin within weeks and accumulate across decades. Doll and Peto's 50-year follow-up of British doctors (PMID 15213107) showed that lifetime smokers lose roughly 10 years of life expectancy, but quitting by age 40 avoids more than 90% of the excess mortality risk. Jha et al. in NEJM (PMID 23343063) confirmed the same pattern in a modern US cohort.

Second, the 58% "not preventable" figure isn't a counsel of despair. It reflects the unavoidable biology of being a multicellular organism. Every time a stem cell divides, there is a small probability of a somatic mutation (a DNA change that happens in one cell during your lifetime, not inherited). Most mutations are harmless. Some are catastrophic. A 2015 Tomasetti-Vogelstein analysis in Science famously argued that stem cell division rates alone explain a majority of inter-tissue cancer risk variation, which is why pancreatic and small-intestine cancer rates are so different despite identical environmental exposures. You can reduce the 42%. You cannot eliminate the other 58%.

Third, most of that 42% is governed by a small number of behaviors. Smoking + weight + alcohol + UV alone account for ~37% of the total. Everything else — diet, activity, infections, environmental exposures — competes for the remaining sliver. Prioritize accordingly.

Part 2 — Modifiable Risk Factors, Ranked by Impact

1. Tobacco (smoking + smokeless)

Evidence grade: overwhelming. Tobacco is a confirmed cause of at least 12 cancers, including lung, larynx, oral cavity, pharynx, esophagus, stomach, pancreas, liver, kidney, bladder, cervix, and acute myeloid leukemia. The US Surgeon General's reports from 1964 through 2020 provide the primary synthesis.

The key numbers:

• Smokers have ~15–30× the lung cancer risk of never-smokers.
• Lifetime smokers lose ~10 years of life expectancy (Doll & Peto 2004; Jha 2013).
• Cessation benefits are strongly time-dependent: quitting by 30 is near-total recovery of baseline risk; quitting by 40 avoids >90% of excess mortality; quitting at 50 still avoids ~half; quitting at 60 still extends life.

Vaping / e-cigarettes: long-term cancer data are immature. They are almost certainly less carcinogenic than combustible tobacco but almost certainly not risk-free. For an established smoker, switching is harm reduction; for a never-smoker, they are a risk without a benefit.

2. Excess body weight

Evidence grade: convincing. The IARC Working Group in 2016 (Lauby-Secretan et al., NEJM, PMID 27557308) concluded there is sufficient evidence that absence of excess body fat reduces the risk of 13 cancers: esophageal adenocarcinoma, gastric cardia, colon and rectum, liver, gallbladder, pancreas, postmenopausal breast, endometrium (uterus), ovary, kidney, meningioma, thyroid, and multiple myeloma.

Mechanisms are plausible and multiple: chronic low-grade inflammation, elevated insulin and IGF-1 (insulin-like growth factor 1, a hormone that promotes cell growth), elevated circulating estrogens from adipose-tissue aromatase (especially relevant for postmenopausal breast and endometrial cancer), altered bile acid metabolism in the colon, and adipokine signaling.

What "excess body weight" means in the literature is imperfect: most studies use BMI (body mass index — weight divided by height squared), which is a crude proxy for adiposity. Waist circumference and waist-to-hip ratio are better markers of visceral fat, which appears to drive most of the metabolic risk. The practical target: sustain a body composition where visceral fat is low. The tool for measuring this well is DEXA (dual-energy X-ray absorptiometry), available at most sports medicine and imaging centers.

3. Alcohol

Evidence grade: convincing. Alcohol is a Group 1 carcinogen (IARC Monograph Vol. 100E, 2012) and a convincing cause of cancers of the mouth, pharynx, larynx, esophagus (squamous), liver, colon and rectum (men), and female breast (both pre- and postmenopausal).

The comprehensive dose-response meta-analysis is Bagnardi et al., British Journal of Cancer 2015 (PMID 25422909). Risk increases linearly for several cancers even at "light" intake. The 2018 Global Burden of Disease alcohol analysis in the Lancet (PMID 30146330) concluded there is no safe level of alcohol consumption when total health risk is considered, and in January 2025 the US Surgeon General issued a formal advisory calling for updated cancer warning labels on alcohol.

The honest framing: one drink a day meaningfully raises breast cancer risk. Two drinks a day meaningfully raises colorectal and liver risk. This is not moralism; it's a dose-response curve. If you drink, drinking less is better. If you don't drink, there is no cancer-prevention reason to start.

4. Ultraviolet radiation

Evidence grade: convincing. UV (from sun and tanning beds) causes basal cell carcinoma, squamous cell carcinoma, and melanoma. The practical tools are obvious and boring: shade, clothing, hats, broad-spectrum sunscreen, and avoidance of tanning beds. Indoor tanning before age 35 raises melanoma risk by ~60%. Tanning beds are Group 1 carcinogens.

5. Physical inactivity

Evidence grade: strong, especially for colon and endometrial cancer. The largest single analysis is Moore et al. in JAMA Internal Medicine 2016 (PMID 27183032), a pooled analysis of 1.44 million adults across 12 cohorts. Higher leisure-time physical activity was associated with lower risk of 13 of 26 cancers examined, with risk reductions of 10–42%, including esophageal adenocarcinoma, liver, lung, kidney, gastric cardia, endometrial, myeloid leukemia, myeloma, colon, head and neck, rectal, bladder, and breast.

The current HHS guideline — 150–300 minutes per week of moderate activity or 75–150 of vigorous activity, plus two resistance training sessions — is the evidence-based target. More is modestly better up to perhaps ~300 minutes/week; above that, cancer-specific returns flatten.

6. Diet

This is where the wellness industry does most of its damage. Here is what actually holds up after decades of prospective cohorts and a handful of randomized trials:

Holds up (convincing or probable, per WCRF/AICR 2018):

• Processed meat (bacon, ham, sausages, hot dogs, deli meat) is a Group 1 carcinogen and a convincing cause of colorectal cancer (Bouvard et al., Lancet Oncology 2015, PMID 26514947).
• Red meat (beef, pork, lamb) is a probable cause of colorectal cancer at high intake.
• Dietary fiber and whole grains are convincing protective for colorectal cancer.
• Mediterranean-pattern diet showed a significant reduction in breast cancer incidence in the PREDIMED trial's EVOO (extra-virgin olive oil) arm (Toledo et al. JAMA Intern Med 2015, PMID 26365989). This is one of the few randomized diet-and-cancer findings at all.
• Dairy / calcium is probable protective for colorectal.

Weak or inconsistent:

• Soy and breast cancer (appears neutral to slightly protective; not harmful at dietary doses).
• Coffee (probably protective for liver and endometrial cancer at moderate intake).
• Specific "superfoods" (blueberries, broccoli sprouts, turmeric as food). Plausible, not proven.

Failed or harmful in trials:

• Low-fat dietary pattern for breast cancer prevention (Women's Health Initiative — null).
• Beta-carotene supplementation in smokers — actively harmful (see below).

The practical synthesis: eat mostly plants, lots of fiber, fish a couple times a week, olive oil, minimal processed meat, modest red meat, modest alcohol. That is more or less what PREDIMED tested. It is also more or less what every major cancer society recommends. The Mediterranean-pattern label is a convenient handle but the underlying principle is simply: dietary fiber and plant diversity up, ultra-processed food down.

7. Infections

About 13% of cancers globally are attributable to infections. The big ones:

• HPV → cervical, anal, oropharyngeal, vulvar, vaginal, penile cancer.
• Hepatitis B and C → hepatocellular carcinoma (liver cancer).
• H. pylori → non-cardia gastric cancer and gastric lymphoma.
• Epstein-Barr virus → nasopharyngeal carcinoma and some lymphomas.

The HPV and HepB pieces are the most actionable (vaccines — see Part 5). H. pylori is diagnosable with a breath or stool test and curable with a 2-week antibiotic course; screening in high-prevalence populations reduces gastric cancer incidence.

Part 3 — Screening: The Tests That Actually Save Lives

Screening is where cancer prevention gets technical. "Early detection" sounds universally good, but in fact a screening test is only worth doing if large randomized trials show it reduces mortality — not just finds more cancers. Many historically popular screens failed that test. The ones below passed.

Colorectal cancer — strong evidence

Colorectal cancer is the screening success story. Multiple large RCTs — UK Flexible Sigmoidoscopy Trial (Atkin et al. Lancet 2010, PMID 20430429), Minnesota FOBT, and the NordICC colonoscopy trial (Bretthauer et al. NEJM 2022, PMID 36214590) — consistently show that screening reduces colorectal cancer incidence and mortality. Colonoscopy is the most complete test (it finds and removes precancerous polyps during the same procedure); FIT (fecal immunochemical test) is non-invasive, annual, and nearly as effective at population level.

Current guideline (USPSTF 2021): start at age 45 for average-risk adults, continue through 75, individualize 76–85. Earlier if family history.

Lung cancer — strong evidence, narrow eligibility

The National Lung Screening Trial (NEJM 2011, PMID 21714641) showed a 20% reduction in lung cancer mortality with annual low-dose CT in high-risk current and former smokers. The Dutch-Belgian NELSON trial (de Koning et al. NEJM 2020, PMID 31995683) replicated the finding: 24% reduction in men, 33% in women.

Current guideline (USPSTF 2021): annual low-dose CT for adults 50–80 with a 20 pack-year smoking history who currently smoke or quit within the past 15 years. If you qualify, this is one of the highest-yield screens in medicine. Uptake in eligible patients is still below 20% in the US — a major unmet opportunity.

Breast cancer — strong evidence

Mammography reduces breast cancer mortality by approximately 20% in screened women ages 50–70, per the independent UK Marmot review (Lancet 2012, PMID 23117178), with a tradeoff of roughly one overdiagnosis per three cancers detected.

Current guideline (USPSTF 2024): biennial mammography starting at age 40 through 74. Earlier and more intensive for women with known genetic risk (BRCA1/2) or strong family history.

Cervical cancer — strong evidence + rapidly improving via HPV testing

HPV testing has largely replaced or joined cytology (Pap smear) because it's more sensitive. The Ronco et al. pooled European RCT analysis in Lancet 2014 (PMID 24192252) showed HPV-based screening was 60–70% more effective than cytology at preventing invasive cervical cancer.

Current guideline: HPV test every 5 years from age 25 or 30 (some countries) through ~65.

Prostate cancer — individualized

This is the most contested screen. The European ERSPC trial (Schröder et al. Lancet 2014, PMID 25108889) showed a 21% reduction in prostate cancer mortality with PSA screening. The US PLCO trial was initially null but was later shown to be contaminated (many men in the "control" arm had PSA testing anyway). On balance, there is a real but modest mortality benefit, accompanied by real overdiagnosis and overtreatment harms.

Current guideline (USPSTF 2018): individualized decision ages 55–69 after a discussion of benefits and harms. Men with African ancestry or first-degree family history are higher risk.

What doesn't earn a screen (for average-risk adults)

Whole-body MRI, circulating tumor DNA "liquid biopsy" panels (Galleri and others), CA-125 for ovarian cancer, full-body CT — none of these currently have mortality-benefit RCT data in average-risk populations. They find things. Whether finding those things helps you live longer is, as of 2026, unproven. Some will probably prove out. Some will prove to be net harmful. If you choose to do them, do so with eyes open about the evidence grade.

Part 4 — Vaccines: The Quietly Revolutionary Piece

Vaccines are the most underdiscussed cancer-prevention intervention in the longevity space, which is odd because the effect sizes are enormous.

HPV vaccine

Lei et al. in NEJM 2020 (PMID 32997908) followed 1.67 million Swedish girls and women and found that HPV vaccination before age 17 was associated with an ~88% reduction in invasive cervical cancer. Falcaro et al. in Lancet 2021 (PMID 34741816) reported near-elimination of cervical cancer among UK women vaccinated at ages 12–13.

The HPV vaccine also prevents a significant share of anal, oropharyngeal, vulvar, vaginal, and penile cancers. It is approved in the US through age 45; catch-up vaccination in adults up to 26 is routinely recommended and up to 45 is shared-decision.

Hepatitis B vaccine

Universal childhood HepB vaccination in Taiwan produced roughly an 80% reduction in childhood hepatocellular carcinoma in the vaccinated cohort compared with unvaccinated. HepB vaccine is part of the standard childhood schedule in most countries and is recommended for all unvaccinated adults under 60 (and selectively for older adults at risk).

Neither of these is a "longevity hack." They are just the highest-yield cancer prevention interventions that exist, full stop, and they belong in every honest cancer-prevention article.

Part 5 — What Doesn't Work: The Supplement Graveyard

This section is where the longevity space gets the most uncomfortable. Cancer prevention is the one field where supplements have been tested in large, well-designed randomized trials, and the results have been overwhelmingly negative — sometimes spectacularly negative.

Beta-carotene — actively harmful in smokers

• ATBC trial (Alpha-Tocopherol, Beta Carotene), NEJM 1994 (PMID 8127329): 29,000 Finnish male smokers given beta-carotene (20 mg/day) had an 18% higher lung cancer incidence and 8% higher total mortality than placebo.
• CARET trial, NEJM 1996 (PMID 8602180): beta-carotene + retinol in 18,000 smokers and asbestos workers increased lung cancer 28% and mortality 17%. Trial stopped early for harm.

Two large, well-designed trials both showed active harm. Beta-carotene supplementation in smokers is one of the most clearly disproven interventions in modern preventive medicine.

Vitamin E and selenium — null and then harmful

The SELECT trial (Lippman et al. JAMA 2009, and Klein et al. JAMA 2011, PMID 21990298) randomized 35,000 men to vitamin E, selenium, both, or placebo for prostate cancer prevention. The primary endpoint was null. Extended follow-up found vitamin E alone increased prostate cancer incidence by 17%.

Vitamin D — null for total cancer incidence

The VITAL trial (Manson et al. NEJM 2019, PMID 30415629) randomized 25,000 adults to 2,000 IU/day vitamin D3 or placebo. Over 5.3 years, there was no reduction in total cancer incidence (the primary endpoint). Secondary analyses hinted at a possible reduction in cancer mortality with longer follow-up, but the primary endpoint was null. Vitamin D is important for bone health and is reasonable to replete if you are deficient. It is not, on current evidence, a cancer prevention tool.

Multivitamins — a tiny, ambiguous signal

The Physicians' Health Study II (Gaziano et al. JAMA 2012, PMID 23162860) found an 8% reduction in total cancer incidence in men taking a daily multivitamin over 11 years. Modest, borderline significant, not replicated in women. This is the single "positive" large supplement trial in cancer prevention and the effect is small.

Antioxidant supplements generally

The Cochrane systematic review of antioxidant supplements (Bjelakovic et al. 2012, PMID 22419320) — 78 trials, 296,000 participants — found no benefit on mortality and, for beta-carotene, vitamin E, and high-dose vitamin A, a small increase in mortality.

The popular botanicals

Curcumin, green tea catechins (EGCG), resveratrol, quercetin, sulforaphane, and similar plant compounds have interesting preclinical data (cell culture, animal models) and thin-to-absent human RCT data for cancer prevention. That doesn't make them fraudulent. It makes them unproven. If a supplement label or influencer claims "cancer-fighting," the correct translation is usually "there was a Petri dish paper."

The honest summary on supplements for primary cancer prevention: almost nothing has proven benefit, several things have proven harm, and the supplement industry's track record in this field is the worst in preventive medicine. Get your nutrients from food. Correct documented deficiencies. Be skeptical of the rest.

Part 6 — A Realistic Role for Supplements (the Footnote)

To be maximally clear, because this space has been abused: the role of dietary supplements in evidence-based cancer prevention is, at best, small and specific.

• Correct documented deficiencies. If bloodwork shows genuine vitamin D deficiency, repleting is reasonable for bone and general health — not because it will prevent cancer.
• Folate for people planning pregnancy — relevant to neural tube defects, not cancer prevention in adults.
• Calcium and vitamin D may have modest colorectal-adenoma benefit in some trials, but the effect is small and the VITAL primary endpoint was null for total cancer.
• Aspirin (not a supplement, but an over-the-counter intervention) has data from Rothwell et al. Lancet 2011 (PMID 21144578) and others showing long-term use reduces colorectal cancer mortality — but the USPSTF in 2022 pulled back prior primary-prevention recommendations because the bleeding risk is meaningful and the net benefit is individual. Do not start aspirin on your own; discuss with your doctor.

Nothing else in the supplement aisle has convincing randomized evidence for cancer prevention in an average-risk adult. If that is disappointing, it is also clarifying.

Part 7 — What You Can Do (the Evidence-Based Action List)

If you want your effort to track the data, here is the rank-ordered list.

1. Don't smoke. If you smoke, quit. This is 29% of cancer deaths and by far the single largest lever. Use whatever combination of counseling, nicotine replacement, varenicline, or bupropion works for you; the best quit strategy is the one that succeeds.
2. Stay lean, particularly around the abdomen. Excess visceral fat drives 13 cancers. The target is not a magazine body; it's a waist circumference and body composition that keeps fasting insulin and inflammatory markers low. For most people, that means resistance training, protein sufficiency, enough sleep, and consistent energy balance.
3. Move most days. 150–300 minutes/week moderate activity (brisk walking, cycling, swimming) plus 2 resistance sessions is the threshold. More is modestly better up to ~300 minutes; diminishing returns beyond.
4. Drink less alcohol. There is no safe level for cancer risk. If you drink, fewer drinks and fewer drinking days is straightforwardly better. If you don't drink, don't start.
5. Get screened on schedule. Colonoscopy or FIT from age 45. Mammography from age 40 (biennial). HPV testing from age 25–30. Low-dose CT if you meet the lung screening criteria. PSA after informed discussion if you are a man 55–69. These are the screens with mortality-benefit RCT data.
6. Get vaccinated. HPV (through age 45 is allowable). Hepatitis B if unvaccinated. These are the highest-effect-size cancer prevention interventions in existence.
7. Eat a Mediterranean-pattern diet. Lots of plants, fiber, olive oil, fish, legumes, nuts. Modest red meat. Minimal processed meat. This is what PREDIMED tested and what the WCRF/AICR synthesis supports.
8. Sun-protect. Shade, clothing, hats, broad-spectrum sunscreen. No tanning beds ever.

If you do those eight things, you will have done essentially everything that has strong evidence behind it. Everything else — including the entire "cancer-fighting supplement" category — is debate material, not actionable medicine.

FAQ

Is cancer mostly genetic or environmental? Mostly neither, in the usual sense of those words. Only ~5–10% of cancers are driven by clearly inherited high-penetrance mutations (BRCA1/2, Lynch syndrome, Li-Fraumeni, etc.). Roughly 42% are attributable to known modifiable risk factors. The remainder reflect the cumulative somatic mutation burden that comes with cell division over time — essentially, biological chance in cells that divide a lot. "Bad luck" is an imprecise but not inaccurate shorthand for that residual.

Does stress cause cancer? There is no convincing evidence that psychological stress directly causes cancer. There is evidence that chronic stress contributes to behaviors that do cause cancer (smoking, drinking, poor sleep, inactivity, weight gain) and may affect treatment outcomes and immune function. Reducing stress is good for you. Marketing it as a direct cancer prevention tool overstates the data.

Should I take vitamin D to prevent cancer? No — not for cancer prevention. The VITAL trial found no effect on total cancer incidence at 2,000 IU/day over 5.3 years. Vitamin D is worth repleting if you are deficient, for bone and general health. It is not a cancer prevention intervention.

What about sugar "feeding" cancer? Cancer cells consume glucose avidly, which is how PET scans work — but dietary sugar does not selectively feed tumors. What sugar does do is contribute to weight gain, insulin resistance, and metabolic dysfunction, which are legitimate cancer risk factors. So the indirect path (sugar → excess adiposity → cancer) is real. The direct path ("sugar feeds tumors") is a misinterpretation of metabolic biology.

Are organic vegetables better for cancer prevention than conventional? The cancer-relevant variable in diet is whether you eat the vegetables at all, and in what variety. Large cohort analyses have not found meaningful cancer-incidence differences between organic and conventional consumption, and eating more conventional vegetables beats eating fewer organic ones by a wide margin.

I'm already doing everything right. What else can I do? Beyond the eight-item list above, there is genuinely little with strong evidence. If you have a strong family history, see a genetic counselor. If you have specific risk factors (Barrett's esophagus, familial adenomatous polyposis, prior radiation, etc.), individualized surveillance plans exist. Otherwise, the marginal returns on additional interventions are small and uncertain.

What about the new multi-cancer early detection (MCED) blood tests like Galleri? Interesting technology; immature evidence. MCED tests can detect cell-free DNA signals from multiple cancers in a single draw, but as of 2026 no MCED test has randomized-controlled-trial evidence of mortality benefit in average-risk adults. That may change. For now, they are best used inside research studies or in clearly defined high-risk populations, not as routine screening.

Closing: The Discipline of Saying "We Don't Know"

Cancer is the field where preventive medicine is at its most honest. It is a field where beta-carotene supplements — which looked good in observational data and were universally assumed to be safe — actively killed smokers in randomized trials. Where vitamin E, which was supposed to reduce prostate cancer, modestly increased it. Where "superfoods" perform well in cell culture and disappear in humans.

The discipline the data enforces is this: trust only interventions that have been tested at scale in people, with the right endpoints, and replicated. When you apply that standard, the list of cancer prevention tools gets small, boring, and unignorable. Don't smoke. Stay lean. Move. Drink less. Get screened. Get vaccinated. Eat plants and fiber. Protect your skin.

Everything outside that list is either untested, disproven, or marketing. A genuinely useful article on cancer prevention has to say so, even when the cultural incentives run the other way.

The 42% that is preventable is enormous — it is millions of lives globally, every year. The 58% that isn't is the price of being a living system built from dividing cells. Acting on the first half is not a guarantee, and pretending otherwise is its own kind of harm. But it is by far the best hand anyone has figured out how to play.

This article is educational content and not medical advice. Screening schedules and individual risk vary — discuss personal prevention strategy with a qualified clinician.