It has been found people diagnosed with Type 2 diabetes are at an increased risk for colorectal carcinoma, or cancer. Diets causing inflammation have been linked to such cancer and a species of bacteria, according to a study reported on in April 2018 in the Journal Clinical Gastroenterology and Hepatology.

Scientists at Harvard Medical School in the United States and Huazhong University in China compared the nutrition of the participants in the Nurses' Health Study and Health Professionals Follow-up Study. The participants kept diaries of the foods that they ate over the years. Based on eighteen foods associated with pollution, researchers ranked the participants' diets according to the empirical dietary inflammatory pattern (EDIP). This score tells investigators the amount of inflammation likely to be present.

A total of 124,433 participants suffered 951 cases of colorectal cancer over a 28 year period. The ones with the highest EDIP scores were at the highest risk for colon and rectal cancer linked with the bacterial species Fusobacterium nucleatum. The investigators concluded inflammatory regimes change the bacterial species in the colon and rectum and encourage the growth of colon and rectal cancer. Since Type 2 diabetes is a disease of inflammation, this could be the link between this condition and colorectal cancer.

Fusobacterium nucleatum is known for causing a great many diseases, including periodontitis, a disease-causing loss of teeth as well as inflammatory bowel disease (Crohn's disease and ulcerative colitis). Drinking green and black tea are of interest as being a possible way to prevent periodontitis caused by this bacteria. Penicillin antibiotics, as well as other antibiotics such as metronidazole and piperacillin, are prescribed for treatment.

In 2015 the Journal of the American Diabetes Association, Diabetes Care, noted a study in which people with Type 2 diabetes had a 30 percent higher risk of colorectal cancer than non-diabetics. Obese people with Type 2 diabetes who had been unusually overweight for four years or over also had an increased risk of this kind of cancer.

Screening for colorectal cancer can include looking for …

  • blood in the stool,
  • searching for abnormal DNA, or
  • viewing the colon and rectum directly with fiber optics (a tube with a light at the end). How often this should be done depends upon the risk factors and should be discussed with one's doctor.

Treatment for colorectal cancer includes …

  • surgery,
  • chemotherapy, and
  • radiation.

Surgery is undertaken to remove the diseased section of the colon and sometimes the adjacent lymph nodes. Then chemotherapy or radiation can be used to prevent new tumors from growing.

Chemotherapy treatments include …

  • 5-Fluorouracil (5-FU),
  • irinotecan (Camptosar)
  • oxaliplatin (Eloxatin),
  • trifluridine and tipiracil (Lonsurf),
  • capecitabine (Xeloda), and
  • vincristine.

Often two or more of these drugs are combined, which makes them work better.