Around four in ten cancers are preventable with tools we already own: vaccines, tobacco control, weight, alcohol, sun and infection control.
About 40% of cancer cases and nearly half of cancer deaths in high-income countries are attributable to modifiable risk factors, tobacco above all, followed by excess body weight, alcohol, infections, diet, inactivity and ultraviolet exposure. Proven interventions exist for most of them: HPV vaccination (a single dose is now WHO-endorsed) can eliminate cervical cancer as a public health problem; hepatitis B vaccination and hepatitis C treatment prevent liver cancer; Helicobacter pylori eradication reduces gastric cancer; tobacco taxation, plain packaging and smoke-free laws are the most cost-effective measures in all of medicine; aspirin halves colorectal cancer in Lynch syndrome carriers. Yet global HPV coverage remains well below target, tobacco still kills more than eight million people a year, and prevention receives a small share of cancer research and health spending. The bottleneck is political, financial and organisational rather than scientific.
Around four in ten cancers are preventable with tools that exist now. This would fund the hard, unglamorous work of getting vaccines, screening and tobacco control to everyone, paid on results.
CHALLENGE proved exercise works in colon cancer but not how much is needed. A trial comparing doses, as we would for a drug, would tell health systems what to fund.
People with Lynch syndrome have a very high lifetime cancer risk from a predictable set of mutations. Vaccinate them against those shared mutations before cancer appears.
People with cirrhosis have a high risk of liver cancer, and those who happen to take statins seem to get it less often. A proper trial would settle whether statins should be prescribed for prevention.
Lynch syndrome tumours share predictable mutations the immune system can target. A vaccine in early trials could be tested to see if it prevents polyps and cancers in carriers.
People are invited separately for bowel, breast, cervical and lung screening, and partial participation is common. One appointment at 50 and 60, modelled on the NHS Health Check, offering every eligible test plus family history and risk assessment with navigation support, would raise uptake.
A pill on a string collects cells from the food pipe and finds Barrett's oesophagus, a precursor of cancer. Offering it in pharmacies to people on long-term heartburn drugs would find it early.
Precancer is treated by cutting away part of the cervix, which raises pregnancy risks. A vaccine that makes the immune system clear the infected cells would avoid surgery.
Obesity raises the risk of 13 cancers, and GLP-1 weight-loss drugs are already in routine use for diabetes and obesity. Observational data hint that they cut obesity-related cancers but confounding is severe, so a randomised trial in adults aged 50 to 70 with a BMI of 30 or more should make cancer the primary outcome.
A childhood vaccine against the stomach bacterium behind most stomach cancer would prevent infection for life. One trial in China showed protection; the idea has stalled.
Instead of separate screening programmes for a few cancers, assess every adult's overall cancer risk and offer blood tests, imaging and preventive treatment tuned to that risk, all inside one system that learns.
EBV infects almost everyone and causes nasopharyngeal cancer, some lymphomas and some stomach cancers. A vaccine given before infection could remove those cancers.
H. pylori eradication often fails because of antibiotic resistance. A stool DNA test showing which antibiotics will work would raise cure rates and protect antibiotics.
Sunbeds cause melanoma, especially when used young. Australia and Brazil have banned them. Other countries should follow and measure the effect.
Fear of losing insurance is a top barrier to genetic testing in surveys. Extending non-discrimination law to life and disability cover, as Canada's 2017 Genetic Non-Discrimination Act does and the US law does not, would remove that fear and raise cascade testing in families.
Most people do not know alcohol causes seven cancers. Ireland is putting cancer warnings on bottles; other countries should follow and measure the effect on drinking.
HPV throat cancer now exceeds cervical cancer in some countries and mostly affects men, who were not vaccinated. Vaccinating men up to 45 could reduce it.
People who carry the typhoid bacterium in their gallbladder long term have about four times the usual risk of gallbladder cancer. Two meta-analyses suggest offering them gallbladder removal or regular scans; no programme has tried it.
Pharmacies are everywhere and open late. They could give HPV vaccines, hand out bowel test kits, run stop-smoking clinics and offer HPV self-sampling under one roof.
The HPV vaccine prevents most cervical cancer, but false safety claims have cut uptake in several countries. Rebuild confidence locally and deliver the vaccine in schools.
We do not know whether ultra-processed food raises cancer risk because it makes people fat, or because of something in the food itself. Feeding volunteers matched diets for a few weeks and measuring cancer-relevant biology can tell the two apart.
Hepatitis C is now curable in weeks. Testing and treating where it is concentrated, and keeping those with scarring in surveillance afterwards, would cut liver cancer.
The rules that decide who gets a lung scan count cigarettes. A risk model that also uses age, sex, family history, deprivation and lung disease would find more cancers in the same number of scans, and would stop excluding people who smoke less but are more likely to get the disease.
About one in eight cancers is caused by an infection we can vaccinate against, cure or eradicate. A concerted global programme could make those cancers rare within a generation.
Scotland and Wales put a floor under the price of alcohol. Deaths from liver disease have already fallen. Cancer takes longer to show, so someone has to keep measuring for a decade.
Air pollution causes lung cancer in people who never smoked. Clean air zones and coal phase-outs should be tracked against never-smoker lung cancer rates.
Lung screening is a teachable moment. Giving cessation medicine and support by default at every scan, unless the person opts out, roughly doubles quit rates.
Stomach cancer is largely caused by a bacterium that spreads in households. Testing and treating whole families, not individuals, would stop reinfection and prevent cancer.
Bowel cancer in people under 50 is rising by 2 to 8 percent a year on both sides of the Atlantic and nobody knows why. The strongest lead is a toxin made by some gut bacteria whose damage signature is three times more common in young patients and is stamped on the colon early in life. If that is the cause, the fix is in childhood, not in a screening programme.
A three-year supervised exercise programme after chemotherapy cut recurrence and death by roughly a third in 889 patients, an effect the size of adjuvant chemotherapy. No health system has a funding line for it.
Aspirin roughly halves bowel cancer in Lynch syndrome, and a dose trial is defining how little is needed. Most carriers are still not prescribed it; the task is to fix prescribing.
Womb precancer in women with obesity is usually treated with a hormone coil or hysterectomy. Weight-loss drugs might reverse it and protect fertility.
Women can collect their own sample for the virus that causes cervical cancer; those who test positive can be treated the same day with a simple heat device. Done nationally, this could eliminate a disease that still kills hundreds of thousands of women a year.
Screening trials are judged on deaths, which take fifteen years to count, and on cancers found, which is the wrong direction. Preventing a man from turning up with cancer already in his bones happens three times as often as preventing a death, arrives years earlier, and is the outcome he cares about.
Millions of people have had weight-loss surgery or now take weight-loss drugs. Linking those records to cancer registries would show, cancer by cancer, how much reversing obesity prevents, for almost no cost.
A 5 mg tamoxifen dose halves breast cancer recurrence after precancer with far fewer side effects than the full dose. Almost nobody is prescribed it. Change who can prescribe.
Dentists see the mouth more than any doctor. A standard, recorded oral cancer examination with a referral route would catch cancers earlier at almost no cost.
Cigarettes with nicotine cut by 95% do not sustain addiction. A mandatory cap, which the FDA has proposed, could cut smoking dramatically.
Radon gas from the ground is the second biggest cause of lung cancer. Testing every home at sale and paying for fixes in high-radon areas would prevent thousands of cases.
Scotland's minimum price per unit cut alcohol deaths. Tracking alcohol-related cancer incidence over the next decade would show whether it also prevents cancer.
Adult women who missed the vaccine could get it at their screening visit. Vaccination around treatment for precancer also seems to cut recurrence.
Blood tests for bowel cancer miss most precancerous polyps, so they should not replace stool tests. But for the third of people who never do any screening, a blood test may beat nothing.
Prevention drug trials run separately in each precancer and are slow. One master protocol with shared infrastructure across Barrett's oesophagus, oral leukoplakia, lung nodules and pancreatic cysts, using regression as an intermediate endpoint and adding or dropping arms adaptively, would test several drugs at once.
Health systems earn from treating cancer, not preventing it. Paying them for lower cancer incidence and earlier stage in their population would flip the incentive.
Most people carrying a high-risk cancer gene do not know it until someone in the family gets cancer. Offer testing to all adults so carriers can be protected before that happens.
Women who never book a smear test are missed by invitation-based screening. Posting an HPV self-sampling kit as the default invitation, as the Netherlands and Australia do, reaches them, and PCR-based self-samples match clinician samples for detecting high-grade precancer.
Cytisine costs a few dollars per course and works about as well as varenicline, but is unavailable in most countries. Global approval and procurement would make quitting affordable.
Chile has paid for preventive gallbladder removal in 35 to 49 year olds with stones since 2006 without a design that can show whether it prevents cancer deaths. Targeting the operation by region, ancestry and risk score, with an evaluation built in, would answer the question the world's only such programme has left open for twenty years.
Few companies develop cancer prevention drugs because trials take decades. If regulators accepted validated precancer endpoints, as they do cholesterol for heart disease, industry would return.
Most ovarian cancers start in the fallopian tubes. Removing the tubes at hysterectomy, or instead of tying them, as British Columbia has done, appears to prevent ovarian cancer.
Where women cannot return for results, test for HPV and treat any precancer the same day with a battery-powered heat probe. This is the fastest route to WHO's cervical elimination target.
Uptake rises when the invitation comes with a booked appointment and text reminders. Make that the default in every screening programme.
Banning tobacco sales to anyone born after a set year, as the UK is doing, could end smoking within a generation. Adopting countries should coordinate evaluation so the evidence is undeniable.
Investors would fund vaccination and screening campaigns up front and be repaid by health systems only if the campaigns hit verified targets, turning future savings into money for prevention now.
One dose of HPV vaccine protects as well as two or three. Halving the doses frees supply to vaccinate far more girls, boys and young adults.
People most at risk of lung cancer are least likely to attend hospital screening. Manchester showed mobile scanners in car parks reach them. Make this the default model.
Hepatitis B causes most liver cancer worldwide, and generic tenofovir suppresses it for under 30 dollars a year. Treating everyone infected, not just those with liver damage, as WHO's 2024 guidelines allow, would cut liver cancer incidence because viral load predicts it and antivirals reduce it in cirrhotics.
About one lung cancer in five happens to someone who never smoked, and they are outside every screening programme in the world. The genomes show it is a different disease that grows more slowly, which is exactly the kind of cancer a screening test could catch.
The only randomised trial of screening colonoscopy cut bowel cancer by 18 percent because only 42 percent of the people invited turned up. A test that is 20 percent more sensitive but is taken by the same people buys far less than an invitation that 20 percent more people accept.
For colon cancer survivors, a prescribed, supported exercise programme is now an evidence-based treatment with a survival benefit comparable to many drugs. Health systems will need to fund exercise consultants as they fund chemotherapy. The trial does not tell us whether unsupervised advice achieves the same.
If a childhood exposure to colibactin-producing Escherichia coli writes APC mutations into the colon decades before a tumour appears, then the rise in early-onset bowel cancer may be preventable by something done in childhood rather than by screening alone.
The only national prophylactic cholecystectomy programme in the world has run for nearly twenty years without a design that can show whether it works. Targeting by region and risk, and building in an evaluation, is the obvious next step.
It reframes air quality as cancer policy rather than respiratory policy, and it explains the shape of lung cancer in never-smokers: the mutations are common and mostly silent, and what differs is whether something inflames the tissue enough to let one of them grow.
A colonoscopy probably does reduce bowel cancer risk for the person who has it, but a programme that offers colonoscopy achieves much less if most people decline. Programmes based on stool tests with high uptake may deliver as much population benefit at lower cost and risk.
There is no safe level of alcohol for cancer risk, and the risk is highest for cancers of the mouth, throat, oesophagus, liver, bowel and breast. Public awareness is low; most people do not know alcohol causes breast cancer. Warning labels and minimum pricing are the policy levers being debated.
School-based vaccination at 12-13 with high uptake nearly abolishes cervical cancer in vaccinated cohorts, even with a vaccine covering only two HPV types. Screening intervals and the future of cervical screening can now be redesigned around vaccination status.
The document that defines who is offered a scan in the United States, and therefore the document any argument about the screening eligibility gap has to engage with. Eligibility is still defined by pack-years and years since quitting rather than by an individual risk estimate.
Shares A single 'cancer check at 60' appointment bundling all screening tests, Make a two-minute mouth cancer check part of every dental visit, A swallowable sponge test for reflux patients, offered in pharmacies, Jade Goody.
Shares Treat everyone with chronic hepatitis B to prevent liver cancer, Put cytisine, a cheap plant-based quit-smoking pill, on every essential medicines list, Same-day HPV test and heat treatment of precancer by nurses in low-income settings, HPV self-testing with same-day treatment as the national cervical programme.
Shares Katie Couric, Once-only flexible sigmoidoscopy screening in prevention of colorectal cancer: a multicentre randomised controlled trial, Markey Cancer Center, University of Kentucky, Increasing incidence of colorectal cancer in young adults in Europe over the last 25 years.
Shares Ban life and disability insurers from using genetic results, Get every Lynch syndrome carrier onto the right dose of aspirin, Population germline screening for hereditary cancer genes with cascade testing, IBIS-I: five years of tamoxifen keeps preventing breast cancer for at least 20 years.
Shares Community-tailored HPV vaccine confidence campaigns with school-based delivery, Effects of a combination of beta carotene and vitamin A on lung cancer and cardiovascular disease, Controlled feeding trials to separate ultra-processing from calories, Cancer warnings on alcohol labels, evaluated as a natural experiment.
Shares Effect of screening on oral cancer mortality in Kerala, India, HPV screening for cervical cancer in rural India (Osmanabad), Vaccine efficacy against persistent HPV 16/18 infection at 10 years after one, two and three doses of quadrivalent HPV vaccine in girls in India, Osmanabad cervical screening trial (HPV testing vs cytology vs VIA).
Shares Decide who is screened for lung cancer by individual risk, not by pack-years, Measurement of prostate-specific antigen in serum as a screening test for prostate cancer, Treat lung cancer in never-smokers as its own disease, with its own detection programme, Treat screening uptake, not test sensitivity, as the thing to optimise, and settle the age extension with a trial rather than a model.
Shares Tobacco 21, Systematic review with meta-analysis: the relationship between chronic Salmonella typhi carrier status and gall-bladder cancer, Family Smoking Prevention and Tobacco Control Act 2009, Cholecystectomy or ultrasound surveillance for chronic typhoid carriers in endemic regions.