They are compiled by expert consensus and published by the World Health Organization's (WHO) International Agency for Research on Cancer (IARC).

[2][3] They are compiled by expert consensus, teams of specialists at the International Agency for Research on Cancer, who summarize information from literature.

[1][6] Each book defines the cause, mechanism, signs and symptoms, basic structure, diagnosis, epidemiology and outcomes of up to 300 types of tumours.

[3] The classifications are updated regularly by an editorial board composed mostly of practicing pathologists,[6][7] who review and agree on definitions and criteria for each tumor.

[9][10] In 2006, the fourth edition was initiated and guided by series editors Fred Bosman, Elaine S. Jaffe, Sunil R. Lakhani, and Hiroko Ohgaki.

[16] A fifth series was released in 2019, in a lighter blue and with a bold "5" on the book spine, to make it distinct from older outdated editions that might inadvertently be referred to.

"[6][1] In it, they noted that heavy reliance on expert consensus relative to structured and controlled systematic reviews may result in bias, giving undue weight to particular literature or missing relevant studies.

[6] In the first volume of the fifth series, 200 tumours or topics were marked as clinically irrelevant, and up to 130 were reported as “unknown”, with no further explanation of whether a detailed literature search was conducted.

[6] They questioned whether these problems could also be reduced by adding evidence‐based practices to the editorial process, but noted that imposing this might not be appropriate, and that some feel that "clinical judgment based on experience" has an importance that may not be emphasised from randomized controlled trials.

[6] In conclusion, they proposed four “non‐negotiables” when carrying out literature reviews that affect important decisions for the WHO Blue Book series: transparency, searching rigor, double checking, risk of bias assessment.