Young-onset colorectal cancer is associated with a personal history of type 2 diabetes
Mikaeel RR., Symonds EL., Kimber J., Smith E., Horsnell M., Uylaki W., Tapia Rico G., Hewett PJ., Yong J., Tonkin D., Jesudason D., Poplawski NK., Ruszkiewicz AR., Drew PA., Hardingham JE., Wong S., Frank O., Tomita Y., Patel D., Vatandoust S., Townsend AR., Roder D., Young GP., Parry S., Tomlinson IP., Wittert G., Wattchow D., Worthley DL., Brooks WJ., Price TJ., Young JP.
Background: Colorectal cancer (CRC) is rising in incidence in young adults, and this observation is currently unexplained. We investigated whether having a personal history of type 2 diabetes mellitus (T2D) was a potential risk factor for young-onset colorectal cancer (YOCRC). Methods: The South Australian Young Onset (SAYO) CRC study is a series of young adults with CRC below age 55. Ninety unrelated YOCRC cases were recruited to the study. Personal history and detailed family history of T2D were obtained at face-to-face interview and confirmed from medical records. Whole exome sequencing was conducted on germline DNA from each CRC case. Controls for personal history studies of T2D were 240 patients with proven clear colonoscopies and no known CRC predispositions. Results: The median age of YOCRC cases was 44 years (18–54) and of controls was 45 years (18–54), and 53% of both cases and controls were females (P = 0.99). Left-sided (distal) CRC was seen in 67/89 (75%) of cases. A personal history of T2D was confirmed in 17/90 (19%) YOCRC patients compared with controls (12/240, 5%; P