Estimates of the worldwide incidence and mortality from 36 cancers and for all cancers combined for the year 2018 are now available in the GLOBOCAN 2018 database, compiled and disseminated by the International Agency for Research on Cancer (IARC). This paper reviews the sources and methods used in compiling the cancer statistics in 185 countries. The validity of the national estimates depends upon the representativeness of the source information, and to take into account possible sources of bias, uncertainty intervals are now provided for the estimated sex‐ and site‐specific all‐ages number of new cancer cases and cancer deaths. We briefly describe the key results globally and by world region. There were an estimated 18.1 million (95% UI: 17.5–18.7 million) new cases of cancer (17 million excluding non‐melanoma skin cancer) and 9.6 million (95% UI: 9.3–9.8 million) deaths from cancer (9.5 million excluding non‐melanoma skin cancer) worldwide in 2018.

American Cancer Society; Centers for Disease Control and Prevention; Swiss Re; Swiss Cancer Research foundation; Swiss Cancer League; Institut National du Cancer; La Ligue Contre le Cancer; Rossy Family Foundation; US National Cancer Institute; and the Susan G Komen Foundation.

Our study briefly reviews the data sources and methods used in compiling the International Agency for Research on Cancer (IARC) GLOBOCAN cancer statistics for the year 2020 and summarises the main results. National estimates were calculated based on the best available data on cancer incidence from population‐based cancer registries (PBCR) and mortality from the World Health Organization mortality database. Cancer incidence and mortality rates for 2020 by sex and age groups were estimated for 38 cancer sites and 185 countries or territories worldwide. There were an estimated 19.3 million (95% uncertainty interval [UI]: 19.0‐19.6 million) new cases of cancer (18.1 million excluding non‐melanoma skin cancer) and almost 10.0 million (95% UI: 9.7‐10.2 million) deaths from cancer (9.9 million excluding non‐melanoma skin cancer) worldwide in 2020. The most commonly diagnosed cancers worldwide were female breast cancer (2.26 million cases), lung (2.21) and prostate cancers (1.41); the most common causes of cancer death were lung (1.79 million deaths), liver (830000) and stomach cancers (769000).

Cancer Incidence in Five Continents (CI5), a longstanding collaboration between the International Agency for Research on Cancer and the International Association of Cancer Registries, serves as a unique source of cancer incidence data from high‐quality population‐based cancer registries around the world. The recent publication of Volume X comprises cancer incidence data from 290 registries covering 424 populations in 68 countries for the registration period 2003–2007. In this article, we assess the status of population‐based cancer registries worldwide, describe the techniques used in CI5 to evaluate their quality and highlight the notable variation in the incidence rates of selected cancers contained within Volume X of CI5. We also discuss the Global Initiative for Cancer Registry Development as an international partnership that aims to reduce the disparities in availability of cancer incidence data for cancer control action, particularly in economically transitioning countries, already experiencing a rapid rise in the number of cancer patients annually.