Gut microflora are a community of bacteria the live in the human digestive tract and help make digestion possible. Although these microflora are separate organisms from humans, they are usually harmless, and even beneficial. However they can also go wrong and cause disease. There bacteria are most beneficial in the proper balance—the negative effects of one group is canceled out by the actions of another. Imbalance leads to illness; for example, some of these bacteria prevent tumor growth in colon cancer, but others increase the growth rate. When the balance is thrown off, these bacteria can cause colon cancer to quickly get out of control.
Other things that hasten the growth of colon cancer is a protein called PLAC8. This PLAC8 protein has been linked with colon cancer for a long time, but the precise nature of the link was poorly understood until recently. While other proteins associated with cancer actually inhibit the body’s own tumor-fighting mechanisms. PLAC8 encourages tumor growth. It alters the interior of the colon so that it is easier for colon cancer to develop and spread. In particular, PLAC8 causes tumors to grow in an irregular, spiked shape, rather than the usual smooth shape; the spikes cause the cancer to be more aggressive, and grow more in the digestive tract.
Risk factors for colon cancer include a personal or family history of the disease, smoking, heavy alcohol use, and being over 50. In addition, people who are obese, who are sedentary, or who eat a high-fat diet are at heightened risk. In a study, health men with a body mass index in the obesity range were more likely to have polyps in screenings. That is why doctors are starting to focus on screenings for obese men, to catch colon cancer early on, when it is most responsive to treatment.
Obese men are also particularly advised to take measures to prevent colon cancer. Losing weight, getting more exercise, and eating more fiber and less fat is the most direct way to lower risk, but there is more that people can do. Low-dose aspirin, commonly used to prevent stroke and heart disease, can also reduce incidence of polyps.