Short answers, pulled from the story.
In 2026, colorectal cancer became the primary cause of cancer-related mortality among Americans younger than age 50. This demographic shift overturned decades of medical assumptions that the disease was exclusively an affliction of the elderly. Deaths among people under 50 have increased by approximately 1.1% per year since 2005.
The APC gene is the most commonly mutated gene in the development of colorectal cancer. This gene normally prevents the accumulation of beta-catenin protein, but when it fails, beta-catenin accumulates and activates proto-oncogenes that drive cell division. Approximately 75 to 95% of colorectal cancer cases occur in people with little or no genetic risk.
Consumption of red meat and processed meats increases the risk of colorectal cancer, while the International Agency for Research on Cancer classifies processed meat as a group I carcinogen. Drinking five glasses of water a day and consuming calcium found in dairy products may decrease the risk of colorectal cancer and adenomatous polyps.
Tumors are consistently associated with reduced microbial diversity and the enrichment of specific taxa capable of promoting inflammation and immune modulation. Fusobacterium species are enriched in colorectal cancer tissue compared with adjacent normal mucosa, and Streptococcus gallolyticus is associated with colorectal cancer in 25 to 80% of people with bacteremia.
In 2018, the American Cancer Society modified their previous screening guideline for colorectal cancer from age 50 down to age 45. This change followed the recognition of increasing cases of early-onset colorectal cancer and reflected the urgent need to adapt to the changing demographics of the disease.
Colorectal cancer disproportionately affects black Americans, where the rates are the highest of any racial or ethnic group in the US. Black Americans are about 20% more likely to get colorectal cancer and about 40% more likely to die from it than most other groups.