The Blue Books Are Back!

When it comes to cancer, the classification of tumors is integral to accurate diagnosis. It also informs research into cancer causation, prevention, and treatment, making a consensus vital for pathologists around the world (1). That’s what the World Health Organisation (WHO)’s Classification of Tumors series – colloquially known as the Blue Books – have been providing for over half a century. But in a rapidly evolving field that no longer relies solely on histopathological features, there is a need for more frequent updates on the way tumors are classified.

That’s why, this year, a new and improved series of Blue Books will return for its fifth edition. Ian Cree, Head of the WHO Classification of Tumors Group, says that the redesigned books feature “a number of major improvements that will drastically improve readability, accessibility, and practicality.” The revamped series will include a modernized layout with two columns of text instead of three (allowing for more and larger images), a multidimensional approach to classification, and tabs on the pages of different chapters to avoid confusion when moving between sections.

“We have done a lot of work on usability because these are essentially bench books, so pathologists need to be able to access them quickly and easily to aid diagnosis and classification,” Cree explains. One worry is that people may use outdated versions of the book by mistake – so the new Blue Books will be a distinctive lighter blue and feature a clear “5” on the spine.

Following extensive feedback, this will also be the first Blue Book series to appear in full online. “The dedicated website will be launched in September and will include up to nine books – two to three of the new fifth series and six of the latest books from the fourth series,” explains Cree. The full classifications will be added to the website as they are developed, and the use of whole slide images promises an immersive digital experience.

The first book in the fifth series, expected in September, will describe digestive system tumors. Prepared by 168 authors and editors and contributed to by hundreds of pathologists across 22 different countries, the book has taken about 15 months to prepare. “The respondents that we surveyed wanted revisions roughly every four years; to deliver that, we’ve had to improve the process at every point,” says Cree. “We now feel that the optimal time to develop each book is about a year.” Along with the usual 12 books, the new series will also include collected works for pediatric tumors, hereditary tumors, and neuroendocrine tumors.