Cancer prevention roadmap: tobacco control and vaccines → biomarker-guided chemoprevention → interception in carriers

Anything that raises the chance of developing a cancer: smoking, alcohol, obesity, sunlight, certain infections, inherited genes, age. Having a risk factor does not mean getting cancer, and many cancers occur without any known one.

Vaccines that prevent the viral infections behind cervical, throat, anal, and liver cancers. The most effective anti-cancer intervention ever created.

Drugs or surgery for people at high inherited risk, before any cancer appears.

The original targeted cancer drug (1977): a pill that blocks oestrogen's effect on breast cancer and halves recurrence, still essential for premenopausal women.

IARC is the WHO's cancer agency, responsible for global cancer statistics (GLOBOCAN), carcinogen classification, and prevention research.

Stopping smoking after a cancer diagnosis improves survival, reduces treatment complications and second cancers, and is the single most effective supportive intervention that oncology services still routinely fail to deliver.

A vaccine against nine HPV types that prevents about 90% of cervical cancers, and now works with a single dose.

A swab tested for the virus that causes cervical cancer, more accurate than the Pap smear and doable at home.

One round of HPV testing in rural Indian villages halved deaths from cervical cancer within eight years, while a Pap smear or a visual check did not, which is why HPV tests are now the world's preferred screen.

Destroying precancerous cervical cells with a heated or frozen probe in under a minute, the tool that makes screen-and-treat possible where there are no surgeons.

A test of the DNA you were born with, to find inherited risk genes such as BRCA or Lynch syndrome.

The company that made BRCA testing a business, now selling hereditary panels and the myChoice, EndoPredict and Prolaris tumour tests.

Removing the fallopian tubes, where most ovarian cancer starts, during other pelvic surgery or in women at inherited risk.

Daily low-dose aspirin lowers bowel cancer risk in people with Lynch syndrome and appears to cut recurrence in bowel cancers with a particular mutation. In healthy older people it caused more harm than good.

The UN health agency that sets global cancer policy: the cervical cancer elimination strategy, the essential medicines list, the childhood cancer initiative and the classification of tumours.

People with cirrhosis or chronic hepatitis B get a liver ultrasound and a blood test every six months so cancer is caught while it is still curable.

Finding and removing polyps before they become cancer. Colonoscopy prevents cancer; stool and blood tests catch it early and get more people screened.

The first randomised trial of colonoscopy screening: being invited cut the risk of bowel cancer by about a fifth, but fewer than half of those invited attended, so the effect on deaths was small.

One shot of HPV vaccine was 97.5% effective against the two most dangerous HPV types, making it realistic to vaccinate the whole world.

When an Indian vaccine trial was halted midway, thousands of girls had had only one shot; following them for ten years showed one dose protected as well as three, changing the world's vaccination policy.

India's first home-made HPV vaccine, protecting against the two virus types that cause most cervical cancers and the two that cause genital warts, at a price meant for a national programme.

The world's largest vaccine maker by doses, which developed CERVAVAC, India's first home-made HPV vaccine, so that cervical cancer prevention no longer depends on imported shots.

A swab tested for the virus that causes cervical cancer, more accurate than the Pap smear and doable at home.

Destroying precancerous cervical cells with a heated or frozen probe in under a minute, the tool that makes screen-and-treat possible where there are no surgeons.

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.

Many women never book a smear test. Sending a self-sampling kit by post, as the Netherlands and Australia do, reaches them and is just as accurate.

One shot for girls and a mail-in swab for women could hit the WHO 90-70-90 targets at a fraction of the cost of the traditional three-dose, clinic-based model.

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.

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.

In healthy older people, daily low-dose aspirin did not extend disability-free life and, unexpectedly, was linked with more cancer deaths. It changed guidelines against routine aspirin in the elderly.

A Nordic trial showing that three years of low-dose aspirin roughly halves recurrence in bowel cancers carrying a particular set of mutations, a biomarker-directed use of a drug that costs pennies.

Add-Aspirin is an 11,000-patient trial across four common cancers in the UK, Ireland and India asking whether cheap daily aspirin after curative treatment stops cancer coming back.

Daily low-dose aspirin lowers bowel cancer risk in people with Lynch syndrome and appears to cut recurrence in bowel cancers with a particular mutation. In healthy older people it caused more harm than good.

A Swedish trial found that cheap aspirin roughly halved recurrence in colorectal cancer patients with a particular tumour mutation. Nobody is going to market it, so health systems must adopt it deliberately.

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.

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.

Removing the fallopian tubes, where most ovarian cancer starts, during other pelvic surgery or in women at inherited risk.

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.

GLP-1 agonists, the new weight-loss injections, lower weight by 15-20%. Early observational data suggest fewer obesity-related cancers in people who take them, but no trial has yet tested cancer as an outcome.

People with severe obesity who have weight-loss surgery develop about a third fewer cancers over the following decade, especially womb and other hormone-related cancers, than similar people who do not.

Excess body fat is an established cause of at least thirteen cancers, including womb, oesophagus, kidney, liver, bowel, pancreas and postmenopausal breast cancer. It is the second largest preventable cause of cancer after smoking in many countries.

Obesity raises the risk of 13 cancers. Weight-loss drugs are now widely used; a large trial should test whether they actually prevent cancer, not just diabetes and heart disease.

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.

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.

Alcohol causes at least seven cancers and there is no safe threshold. Price, availability and cancer warning labels are the tools that work; most people still do not know alcohol causes cancer.

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.

Hepatitis B causes most liver cancer worldwide, and cheap tablets suppress it. Treating everyone infected, not just those with liver damage, would prevent many cancers.

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.

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.

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.

A test of the DNA you were born with, to find inherited risk genes such as BRCA or Lynch syndrome.

Most people who carry a high-risk cancer gene do not know it until they or a relative gets cancer.

Anyone with ovarian, pancreatic, metastatic prostate or mismatch-repair-deficient cancer should be tested for inherited mutations, but many are not. Make it an automatic, opt-out lab step.

When someone tests positive for a BRCA or Lynch mutation, relatives are told only if the patient passes the message on. Most do not. Letting clinics contact relatives directly, with consent, could double testing.

Most people with BRCA or Lynch mutations do not know until they get cancer. Testing everyone once for a short list of high-impact genes would find them in time to prevent it.

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.

A score built from hundreds of common gene variants that says whether your inherited risk of a cancer is higher or lower than average, now being tested as a way to decide who is screened and how often.

Common gene variants shift a person's cancer risk several-fold. A one-time genetic score could tell each person when to start breast, bowel or prostate screening.

Genetic risk scores were built mostly on Europeans and work worse in others. Funding non-European cohorts and setting a portability standard would prevent screening that widens inequality.

UK Biobank is the richest population cohort for linking genes, blood and imaging to who later develops cancer.

Vaccinating people who do not have cancer yet but are very likely to get it, against the antigens their future tumour will carry.

Vaccines against mutations or proteins shared by many patients, so they can be made in advance.

Vaccinate people with BRCA or Lynch mutations against the antigens their future cancers will express, before any cancer exists.

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 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.

BRCA1 breast cancers seem to grow from cells driven by the RANK signal. Denosumab blocks it and is already used for bone. A trial is testing whether it prevents these cancers.

Prevention trials are slow and run separately. A shared platform trial across precancers like Barrett's, oral leukoplakia, lung nodules and pancreatic cysts would test many drugs faster.

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.

Three different ways a cancer stops killing someone: stop it before it starts, remove every last cell, or hold it in check for life. Each needs different technology.

Around four in ten cancers are preventable with tools we already own: vaccines, tobacco control, weight, alcohol, sun and infection control.

Money goes to the cancers and questions that are easy or popular, not the ones with the greatest burden or where a dollar would do most.

The system pays the same for a drug that adds two months as for a cure, so companies race to copy rather than to cure.

Seven in ten cancer deaths happen in low- and middle-income countries, where radiotherapy, pathology, surgery and drugs are scarce.

Finding more cancer is not the same as saving lives. Screening also finds cancers that would never have hurt anyone, and treats them.

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.

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.

ICMR's cancer prevention institute near Delhi, focused on the cancers India can prevent: cervical cancer through HPV screening and vaccination, and oral cancer through tobacco control.