Death from colorectal cancer is highly preventable with screening. Screening can prevent cancer by detecting precancerous polyps (abnormal growths) that lead to colorectal cancer. Screening can also detect colorectal cancer at an early stage, when the cancer can be successfully treated. Colorectal cancer starts when a polyp (or polyps) grows in the colon (the large intestine) or in the rectum, and over time it transforms into cancer. If the polyps are removed through colonoscopy, the person’s chances of developing colorectal cancer are greatly decreased.
Colon Screening
The goal of colon screening is to catch colorectal cancer early enough to increase the chance for cure, which is much greater than if people wait until they have symptoms. Remember that colorectal cancer can be successfully treated when diagnosed early.
For most people, screening should start at age 50, and be repeated regularly. However, if you have a higher risk for colorectal cancer, or a family history of the disease, you may need to start screening at a younger age. It is important to know your risk for this cancer and to understand who needs to be screened.
The most important step you can take to prevent colorectal cancer is regular screening. If you’ve not had screening yet, here is your invitation.
Screening may include stool tests, such as a fecal occult blood test, a fecal immunochemical test, stool DNA tests, flexible sigmoidoscopy, or a colonoscopy.
What's Your Risk?
Colorectal cancer can result from many factors, but many times there is a connection between an individual’s genes, lifestyle, and personal or family history.
Personal or Family History Risk FactorsPeople with a history of inflammatory bowel disease, including ulcerative colitis and Crohn’s disease, and those with a family history of colorectal cancer are at an increased risk for colorectal cancer. If you have a first-degree relative—such as a parent, brother, sister, or child—who has colorectal cancer, you are at an increased risk for this cancer. Also, the age at which your family member had colorectal cancer is important, especially if he or she was under age 60.
Genetic Risk FactorsSome colorectal cancers are caused by a hereditary defect in a gene (also called a genetic mutation). Although inheriting a defective gene greatly increases the risk for this cancer, not everyone with this mutation will end up with cancer.
Some of the hereditary colorectal cancer syndromes are autosomal dominant, meaning you need to inherit only 1 defective gene from either parent; men and women are equally at risk for inheriting the defective gene. If one parent has the mutated gene, you have a 50% chance of inheriting the mutation.
Several genetic conditions may put you at increased risk for colorectal cancer, including:
- Familial adenomatous polyposis (FAP). This is a rare, hereditary disorder that causes hundreds, sometimes thousands, of polyps to develop in the lining of the colon beginning at the teenage years. If these go untreated, the risk for colorectal cancer is nearly 100%, most often before age 40. In some cases, genetic testing can help determine whether you are at risk for this cancer. Gardner’s syndrome is a variation of FAP caused by the same gene that causes FAP, but noncancerous tumors may also develop in other parts of your body, including the skin, bone, and abdomen. The risk for colorectal cancer with Gardner’s syndrome is much lower than with FAP.
- MYH-associated polyposis. Genetic testing can help determine whether you are at risk for MYH-associated polyposis, an inherited condition that is caused by mutations in the MYH gene and is similar to FAP. People with MYH-associated polyposis often develop multiple adenomatous polyps and colorectal cancer at a young age.
- Lynch syndrome. This is the most common form of inherited colorectal cancer. Patients with Lynch syndrome tend to develop relatively few colorectal polyps, but those polyps can quickly become malignant. These patients may have tumors in other organs, including the stomach, uterus, ovaries, the small intestine, and genitourinary tract, but most often in the colon or the rectum.
Age and lifestyle factors can have an impact on your risk for colorectal cancer. These factors include:
- Age, 50 years and older (the risk increases with age)
- Sedentary lifestyle
- Smoking
- Alcohol use
- Increased weight
What's New in Colorectal Treatments?
Along with traditional chemotherapy, immunotherapy and targeted therapies are the newest treatment approaches for patients with colorectal cancer.
Targeted drugsTargeted drugs are newer medications that stop tumors from growing by targeting certain growth factors that stimulate the growth of cancer cells in the tumor. In colorectal cancer, the new targeted drugs target VEGF and EGFR, the 2 growth factors associated with colorectal cancer. Current targeted therapies for colorectal cancer include:
- Avastin (bevacizumab)
- Erbitux (cetuximab)
- Stivarga (regorafenib)
- Vectibix (panitumumab)
- Zaltrap (ziv-aflibercept)
Immunotherapy uses the body’s immune system to kill cancer cells. Currently, there are no immunotherapies available for patients with colorectal cancer. However, such therapies are being developed and are now being tested in clinical trials.
The goal is to develop a vaccine that can treat colorectal cancer and prevent it from recurring (coming back). Vaccine therapy for cancer is meant to increase the patient’s immune system response to help the body fight off the cancer.
Patient Resources
- American Cancer Society
www.cancer.org/cancer/colonandrectumcancer/ - Centers for Disease Control and Prevention
www.cdc.gov/cancer/colorectal/basic_info/screening/index.htm - Exact Sciences Corporation
www.cologuardtest.com - Mayo Clinic:
www.mayoclinic.org/diseases-conditions/colon-cancer/basics/definition/con-20031877 - National Cancer Institute
www.cancer.gov/cancertopics/pdq/genetics/colorectal/HealthProfessional/page1 - National Comprehensive Cancer Network Guidelines for Patients - Colon Cancer
www.nccn.org/patients/guidelines/colon/