What is the leading cause of cancer death worldwide?

The leading cause of cancer death worldwide is lung cancer. Global estimates for 2022 recorded about 1.8 million lung-cancer deaths, more than any other single cancer type.

Lung cancer includes several diseases, but the two broad groups are non-small-cell lung cancer and small-cell lung cancer. Non-small-cell cancers make up most cases and include adenocarcinoma, squamous-cell carcinoma, and large-cell carcinoma. Because early lung cancer may cause few noticeable symptoms, many cases are diagnosed after the disease has advanced, when treatment is more difficult.

Tobacco smoking remains the principal risk factor, but it is not the only one. Second-hand smoke, outdoor and indoor air pollution, radon, asbestos, diesel exhaust, and other workplace exposures can also contribute. Lung cancer can occur in people who have never smoked, including through causes that remain incompletely understood.

The wording “worldwide” matters. Rankings can differ by sex, country, and whether one measures new cases or deaths. Breast cancer leads cancer incidence and mortality among women globally in some datasets, while lung cancer remains the overall leader for cancer deaths across both sexes.