Colorectal Cancer which is also referred by the name of Colon or Rectal Cancer can be defined as a malignant condition which affects the colon and rectum. According to the American Cancer Society, colorectal cancer is the second leading cause in females and third leading cause of fatalities in males. It is estimated that approximately 1 in every 21 males and 1 in every 23 females get affected with colorectal cancer in the United States at some time in their lives.[1,2,3]
There is no known cause for this condition but there are certain risk factors that increase the vulnerability of a person towards colorectal cancer. These include people above the age of 50 being most at risk. Alcohol abuse, obesity and sedentary lifestyle are yet another risk factor for colorectal cancer. A family history of colorectal cancer also increases the risk. Additionally, people with a history of irritable bowel disease, Crohn disease and ulcerative colitis are also at increased risk for developing colorectal cancer.[1,2,3]
However, a new study has shown a clear association of blood infections, both bacterial and viral, with colorectal cancer. Experts believe that this finding is not surprising as the intestine is exposed to high volumes of bacteria and viruses which increase the risk.[1,2,3] This article discusses the link between colorectal cancers and blood infections.
The Link Between Blood Infections And Colorectal Cancer
A new research has highlighted that blood infections both viral and bacterial have an association with colorectal cancer. There are two types of bacteria namely aerobic and anaerobic. While aerobic bacteria require oxygen to thrive and grow, anaerobic bacteria do not require it to function. These bacteria occur naturally in the human body, mostly in the stomach. In most cases, these bacteria do not result in any infections but when these bacteria cause an infection it occurs generally in and around the area where they are located.[2,3]
There had been various studies conducted that proved a clear association between certain types of anaerobic bacteria to colorectal cancer. The researchers wanted to investigate this further and conducted large scale studies. This study was done in Denmark in 2007 and 2016 and over 2 million people were enrolled for the study. To analyze, data of more than 45,000 types of blood infections were collected that included those present in the blood of the people who enrolled in the study.[2,3]
The data was then compared to the information present in the Danish Colorectal Cancer Group database. The researchers specifically looked for fresh cases of colorectal cancer that were diagnosed following a blood infection that was seen to be associated with colorectal cancer. The study gave startling results in that of the 45,000 people who had blood infection 49% went on to develop colorectal cancer. Of these 49%, approximately 1% developed cancer within the very first year of the diagnosis of the blood infection.
The researchers after a thorough analysis concluded that anaerobic blood infections significantly increased the risk for colorectal cancer. As an example, people with known Clostridium septicum were 42 times more likely to develop colorectal cancer than people with people who had blood infections caused by aerobic bacteria within a span of a year. The study also showed only 0.5% of people in the control group who did not have any bacterial infection ended up developing colorectal cancer compared to 21% of those who had Clostridium septicum infection.
However, the co-author of the study Dr. Urik Justesen noted that even though there was a clear link between blood infections and increased risk for colorectal cancer the causal relationship between them was not entirely clear. He stated that it was not clear whether it was the infection that was causing the cancer directly or whether the blood infection was caused by the cancer. He stated that this needed more research on people with cancer who had blood infections.
He states that the future studies will focus more on the specific bacteria in people with colorectal cancer to identify certain characteristics that could be a potential factor in cancer development. He further added that the results of the study would be a major breakthrough in colorectal cancer screening and treatments.