Colorectal cancer is now the leading cause of cancer death in people under 50, the only one of the five leading causes still rising. That is not alarm, it is the data.
Screening in the United States starts at 45. But half of all colorectal cancers diagnosed before 50 occur in people under 45, outside the net entirely, and about 70 percent of early-onset cases carry no family history to flag them. Only 37 percent of the newly eligible are up to date.
What is driving it, nobody can yet say. Diet is the best-established and least specific lead, the microbiome thinner, childhood colibactin exposure the newest and, by its own discoverer's account, still only a hypothesis.
A birthday under the screening line is not proof anyone is already looking. A symptom that persists warrants attention regardless.
