Colorectal Cancer and Cystic Fibrosis
Advances in the understanding and treatment of CF have led to longer life expectancies than ever before. While this is a positive development within the world of CF, it does mean that other conditions that often present later in life may be rising in the aging CF population. One of these potentially co-occurring conditions is colorectal cancer.
The overall risk of getting colorectal cancer is increased by five to ten times in those with CF compared to the general population. This risk increases to 20-30 times higher for those with CF who have also received an organ transplant.1-3
What is colorectal cancer?
The term colorectal cancer refers to cancer that starts in either the colon (colon cancer) or rectum (rectal cancer). Colorectal cancer often starts as a polyp (a small growth) in the colon or rectum that gets larger and invades the walls of the gastrointestinal tract around them. However, it’s important to note that not all polyps cause colorectal cancer. Many are benign, or non-cancerous. If your doctor or healthcare provider tells you that you have a polyp, it does not mean that you certainly have colorectal cancer. A sample of a colorectal polyp can be taken and analyzed further to determine what kind it is.2
If not diagnosed and treated, these cancers can progress to invade many other structures throughout the body, and become metastatic. There are treatment options for colorectal cancer, however, it can be life-threatening if it is not discovered until later stages. This is why it’s important to undergo regular screening for colorectal cancer, especially if you are at an increased risk.
Not everyone with colon cancer will experience symptoms. Those that do may experience blood in the stool, general abdominal pain, changes in bowel habits, or weight loss.2 It’s important to let your doctor or healthcare provider know if you are experiencing these issues as soon as possible.
Why do individuals with CF have a higher risk of getting colorectal cancer?
More information is needed to determine exactly why individuals with CF are at a higher risk of getting colorectal cancer. However, there are some theories as to why this occurs. First, some experts believe that the CFTR (cystic fibrosis transmembrane conductance regulator) gene mutation that is common in cystic fibrosis may play a role in the development of colorectal cancer in CF individuals.
A higher rate of cell turnover (the rate at which cells die and new ones are created to replace them) in the gastrointestinal system has also been thought to play a role in colorectal cancer within those with CF. Long-term mucus-related obstruction and inflammation within the body may also contribute. Another potential reason for the heightened risk may be due to a potential increase in the amount of radiation an individual with CF is exposed to in the form of CT scans or x-rays, among other radiation-involving procedures.1
The risk among those with organ transplants may be higher due to immunosuppressive medications required after transplant. When a person’s immune system isn’t working or is suppressed, their ability to recognize and fight potential cancers is decreased. Additionally, those who receive a transplant may have an increased life expectancy. A longer life expectancy may increase the chances of developing cancer later in life.1 Much more research is needed to fully understand the link between cystic fibrosis and colorectal cancer.
What can those with cystic fibrosis do to decrease their risk?
An important step for anyone, especially those with CF, to take in order to reduce their risk of colorectal cancer is to undergo regular screening. This will allow for earliest possible detection and treatment of a developing cancer.
A colonoscopy is a procedure in which a long, small tube is inserted into the rectum while an individual is sedated or asleep. The tube has a video camera which is used to look at the rectum and colon. Special tools can be used to remove any polyps during the colonoscopy, and these will be sent to a lab for further review.2
It is recommended for the general population to receive colonoscopies beginning at age 50. However, those with CF should be screened starting at 40 years old and every three to five years after, depending on their specific situation. Those with an organ transplant may need to be screened starting at age 30, or within two years after transplant.1-3 Regardless of whether you have had an organ transplant, your healthcare provider will let you know what screening schedule is most appropriate for you.
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