Here is a number that should stop you mid-scroll: nearly four in 10 cancer cases could be prevented. Not in some far-off future. Not with a miracle drug. Right now, with tools we already have. That is the takeaway from the World Health Organisation, which said in a July 2026 report that approximately 38 percent of cancers can currently be prevented by avoiding risk factors and implementing existing evidence-based prevention strategies. Also read | You are cancer-free, then it comes back years later: Medanta oncologist explains why
Cancer remains a leading cause of death worldwide
WHO is not saying cancer is your fault. It is saying a huge chunk is not inevitable, because prevention is about access, information, and systems, not just willpower. Cancer remains a leading cause of death worldwide, WHO said – in 2024, it accounted for nearly 10 million deaths, or nearly one in six deaths globally, and about 400,000 children and adolescents, aged up to 19, develop cancer each year.
The most common new cases in 2024 were reportedly lung (2.6 million), breast (2.4 million), colon and rectum (2.0 million), prostate (1.5 million), skin (non-melanoma) (1.1 million), and stomach (1.0 million). The most common causes of death were lung 1.86 million, colon and rectum 918,000, liver 732,000, breast 694,000, and stomach 642,000, per WHO.
What drives the preventable part?
Tobacco, alcohol, unhealthy diet, physical inactivity and air pollution are risk factors for cancer, WHO said. Nearly a quarter of cancer deaths are reportedly due to tobacco, alcohol, high body mass index, low fruit and vegetable intake, and lack of physical activity, and air pollution is an important risk factor for lung cancer. Also read | Oncologist explains hidden dangers of over the counter nutraceuticals: Know their link to cancer before it is too late
About 10 percent of cancers diagnosed in 2022 were attributed to carcinogenic infections, including Helicobacter pylori, HPV, hepatitis B, hepatitis C, and Epstein-Barr virus, WHO said. Such infections cause about 30 percent of cases in low- and lower-middle-income countries. Hepatitis B and C and some HPV types raise risk for liver and cervical cancer. HIV raises cervical cancer risk six-fold, WHO said.
Cancer, WHO explained, is a generic term for a large group of diseases that can affect any part of the body. One defining feature is rapid creation of abnormal cells that grow beyond usual boundaries and spread to other organs, a process called metastasis. Widespread metastases are the primary cause of death, WHO said.
Cancer arises when normal cells transform into tumour cells in a multi-stage process, driven by genetic factors and physical, chemical, and biological carcinogens, including ultraviolet and ionizing radiation, asbestos, tobacco smoke, alcohol, aflatoxin, arsenic, and infections. Incidence rises with age, WHO said, likely due to cumulative exposure and less effective cellular repair.
So what can reduce risk, according to WHO?
Not using tobacco, maintaining a healthy body weight, eating a healthy diet, including fruit and vegetables, doing physical activity regularly, avoiding or reducing alcohol, getting vaccinated against HPV and hepatitis B if recommended, avoiding ultraviolet radiation from the sun and tanning devices and/or using sun protection, ensuring safe use of radiation in health care, minimising occupational exposure to ionising radiation, and reducing outdoor and indoor air pollution, including radon, a radioactive gas from natural decay of uranium that can accumulate in homes, schools and workplaces.
Prevention is only half the story
Many cancers can be cured if detected early and treated effectively, WHO said. Cancer mortality falls when cases are detected and treated early through screening and diagnosis. Early diagnosis means awareness of symptoms and seeking medical advice when abnormal findings are observed, access to clinical evaluation and diagnostic tests, and timely referral for treatment. Screening aims to find findings suggestive of cancer or pre-cancer before symptoms. Examples are HPV test for cervical cancer, and mammography for breast cancer for women aged 50 to 69, per WHO.
Treatment usually includes surgery, radiotherapy, and/or systemic therapy, WHO added. Correct diagnosis is essential because every cancer type needs a specific regimen. Breast, cervical, oral, and colorectal cancers have high cure probabilities when detected early and treated according to best practices, WHO said.
But access is wildly unequal. Most countries do not fully include essential cancer care in publicly-financed health-benefit packages. Palliative care, which relieves rather than cures symptoms, is essential. Relief is possible for more than 90 percent of patients with advanced cancer, WHO said. Improved access to oral morphine is strongly recommended for moderate to severe cancer pain, suffered by over 80 percent of people with cancer in the terminal phase, WHO said.
So yes, 38 percent is hopeful. It means prevention works. It also means we are not doing enough of it, for enough people, early enough. The most useful takeaway is not guilt. It is this: know your risks, get vaccinated if eligible, do not ignore symptoms, ask about screening, and push for systems that make healthy choices possible, not just personal. Because if nearly four in 10 cases are preventable, that is not just a statistic. That is millions of lives.
Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.
