Among my favorite characters in the Marvel Cinematic Universe (MCU) is King T’Challa, the title character in Black Panther (2018) who appears in other MCU movies. T’Challa was portrayed by the brilliant Chadwick Boseman—even if you are not a fan of the MCU, you might know Boseman from his portrayal of Jackie Robinson in 42 or of Thurgood Marshall in Marshall. He worked on Black Panther while terminally ill, somehow keeping this fact largely unknown and keeping it from stopping his work. He died in 2020 at the age of 43, and he was killed by early-onset colon cancer.
That cancer is on the rise. Here is how a new paper in Nature frames the problem in the first sentences of the abstract:
Incidence rates of colorectal cancer vary geographically and have changed over time. Notably, in the past two decades, the incidence of early-onset colorectal cancer, which affects individuals below 50 years of age, has doubled in many countries. The reasons for this increase are unknown.
Two things to notice about those opening sentences: 1) they clearly outline the background and the urgency of the problem; and 2) they starkly state the knowledge gap. Even without mentioning the devastating human cost, the authors compel us to read on. When we do that, we learn that they undertook a vast international quest to identify mutations that underlie this menace, and how the mutations vary (widely) across continents and in people of different ages. One major finding: colibactin, a mutagen produced by gut bacteria (certain strains of E. coli), likely explains some of the patterns of mutation that cause early-onset colorectal cancer. Interestingly, we know from previous work that the use of antibiotics and the presence of clean water seem to favor the mutagen-making bacteria, and these factors are associated with the alarming increase in this cancer in some parts of the world but not others. These clues offer hope!
Geographic and age variations in mutational processes in colorectal cancer
In Nature, 23 April 2025
From the groups of Ludmil Alexandrov (UCSD), Mike Stratton (Wellcome Sanger Institute), and Paul Brennan (International Agency for Research on Cancer (IARC/WHO)), with collaborators and co-authors from throughout the world.
Snippet by Stephen Matheson
Image credit: Figure 1a from Díaz-Gay et al. cited above (CC BY)