Cancer is thought to be caused by a number of factors including; gender, diet and genetic pre-dispositions. However it looks like microorganisms are another name to be added to that list.
The Hepatitis C & B Viruses cause Liver Cancer, Human Papilloma Virus (HPV) causes Cervical Cancer, Helicobacter pylori is associated with Stomach Cancer & more recently the throat/oral bacterium Fusobacterium and its association with Colon Cancer.
What does this mean? Well there is currently a highly effective vaccine for Hepatitis B. This should mean that the incidence should decrease, however increased alcohol consumption and obesity also increase the risk of this type of cancer.
In the past few years a vaccine against HPV has been developed and is now given to teenage girls to prevent them from getting the virus and decreasing the risk of Cervical Cancer. HPV has also been linked to throat cancer and causes genital warts. If this vaccine is effective against the disease then hopefully the vaccine can be administered to other ‘at risk’groups.
H. pylori has been found in gastric ulcers and, as well as other factors, increases the risk of stomach cancer. In the last few weeks scientists have now found a link between the oral/throat bacterium Fusobacterium and colon cancer. The scientists found the organism was present in the colon of individuals with the disease.
|Fusobacterium necrophorum gram stain under the microscope|
Fusobacterium species are bacteria which thrive in low oxygen environments (they are also rather smelly and give us bad breath). They are found in the mouth and contribute to dental plaque and sore throats. The reason I’m talking a bit more about this organism is because I studied it for my undergraduate dissertation. I studied the organism Fusobacterium necrophorum and its association with ‘Persistent sore throat syndrome’. F. necrophorum was found to be the second commonest cause of bacterial sore throats in the UK, particularly amongst young adults.
Fusobacteriumin Colon Cancer? It can cause disease in the upper respiratory tract, what’s not to say it couldn’t further down? Well TWO teams of scientists identified the bacterium to be present in colon cancer patients. The organism is rarely found in the healthy colon, but has been found in patients with a disease known as Ulcerative Colitis (inflammation of the digestive tract), which itself is a risk factor for Colon Cancer.
Further research is needed, but if Fusobacterium is a risk factor for Colon Cancer then diagnostic tests could be developed. As well as this antibiotics and vaccines could be trialled to see if they have an effect on prevention and treatment of the cancer.
So some cancers seem to have a microbiological risk factor. This has seen us take a new look at Cancer and ways to treat it. However the best action is prevention so reducing the risks such as drinking, smoking and obesity as well as these microbiological risks is essential.