Colorectal cancer is a disease in which cells in the colon or rectum grow out of control. The colon is the large intestine or large bowel. The rectum is the passageway that connects the colon to the anus. Sometimes it is called colon cancer, for short.
Key Takeaways.
- Colorectal cancer is a common and serious disease that affects the colon or rectum.
- Colorectal cancer may not cause symptoms at first, but some signs to watch for are changes in bowel habits, blood in the stool, abdominal pain, and weight loss.
- Colorectal cancer can be caused by genetic or environmental factors, such as age, family history, diet, and lifestyle.
- Colorectal cancer can be treated with surgery, chemotherapy, radiation therapy, targeted therapy, or immunotherapy, depending on the stage and type of the cancer.
- Colorectal cancer can be prevented or detected early by screening and healthy habits.
Symptoms of Colorectal Cancer.
Many people with colorectal cancer do not have symptoms at first. But some common symptoms are:
- A change in bowel habits, such as diarrhea, constipation, or narrowing of the stool.
- Rectal bleeding or blood in the stool.
- Abdominal pain, cramps, gas, or bloating.
- A feeling that the bowel does not empty completely.
- Weakness, fatigue, or weight loss without reason.
Causes and Risk Factors of Colorectal Cancer.
The exact cause of colorectal cancer is not known.
- Age: Most people with colorectal cancer are older than 50. But, the number of younger people with colorectal cancer is increasing.
- Family history: Having a relative with colorectal cancer or certain inherited genetic conditions can increase your risk.
- Personal history: Having had colorectal cancer, polyps, or inflammatory bowel disease can increase your risk.
- Diet: Eating a lot of red meat, processed meat, or fat, and not enough fruits, vegetables, and fiber can increase your risk.
- Lifestyle: Smoking, drinking alcohol, being overweight, or not being physically active can increase your risk.
Types of Colorectal Cancer.
Adenocarcinomas and Their Subtypes.
Adenocarcinomas start in the cells that line the inside of the colon or rectum. They often begin as polyps, which are growths of tissue that can become cancerous. Adenocarcinomas can be further classified into subtypes, such as:
- Mucinous adenocarcinoma: made up of about 60 percent mucus, which may make the cancer cells more aggressive and spread faster than typical adenocarcinomas. It accounts for 10 percent to 15 percent of all colorectal cancers.
- Signet ring cell adenocarcinoma: named for its appearance under a microscope, as the cancer cells look like rings with a hole in the center. It is usually very aggressive and hard to treat. It accounts for fewer than 1 percent of all colorectal cancers.
Gastrointestinal Carcinoid Tumors.
These are tumors that start in the hormone-making cells of the digestive tract. They are usually slow-growing and may not cause symptoms until they spread to other organs.
Primary Colorectal Lymphomas.
These are cancers that start in the lymphatic system, which is part of the immune system. They are rare in the colon and rectum, but more common in the stomach and small intestine.
Gastrointestinal Stromal Tumors.
These are tumors that start in the interstitial cells of Cajal, which are cells that help control the movement of food through the digestive tract. They can occur anywhere in the gastrointestinal tract, but are more common in the stomach and small intestine.
Leiomyosarcomas.
These are cancers that start in the smooth muscle cells of the colon or rectum. They are very rare and tend to grow and spread quickly.
Melanomas.
These are cancers that start in the pigment-producing cells of the skin or other organs. They are very rare in the colon and rectum, but more common in the anus.
Can Colorectal Cancer Kill You?
Yes, colorectal cancer can kill you. Colorectal cancer is the fourth most common cancer and the fourth leading cause of cancer-related deaths in the United States. The survival rate of colorectal cancer depends on the stage, type, and location of the cancer, as well as the patient’s age, health, and treatment options. The earlier the cancer is detected and treated, the better the chances of survival.
The 5-year relative survival rate for localized colorectal cancer is 90% to 91%, but it drops to 73% to 74% for regional cancer and 13% to 18% for distant cancer. Some reasons that may lower the survival rate are:
- Having a family history of colorectal cancer.
- Having certain genetic mutations.
- Having a poor diet, smoking, drinking alcohol, being overweight, or being physically inactive.
Treatments for Colorectal Cancer.
- Surgery: the main treatment for most colorectal cancers. It involves removing the cancer and some surrounding healthy tissue. Sometimes, they may have to remove a part or all of the colon or rectum. This can affect how the patient passes stool.
- Chemotherapy: the use of drugs to kill cancer cells or stop them from growing. It may be given before or after surgery, or alone for advanced cancers. It can cause side effects such as hair loss, nausea, vomiting, and fatigue.
- Radiation therapy: the use of high-energy rays or particles to destroy cancer cells or shrink tumors. It may be given before or after surgery, or alone for advanced cancers. It can cause side effects such as skin irritation, diarrhea, and bladder problems.
- Targeted therapy: the use of drugs that target specific features of cancer cells, such as genes or proteins. It may be given with chemotherapy or alone for advanced cancers. It can cause side effects such as skin problems, high blood pressure, and bleeding.
- Immunotherapy: the use of drugs that help the body’s immune system fight cancer. It may be given alone or with other treatments for advanced cancers. It can cause side effects such as rash, fever, and inflammation.
Prevention of Colorectal Cancer.
Some ways to prevent colorectal cancer or find it early are:
Screening.
The process of checking for cancer or polyps before there are any symptoms. Screening tests can find and remove polyps before they turn into cancer. It can also find cancer at an early stage, when it is easier to treat. Screening tests include stool tests, colonoscopy, sigmoidoscopy, and CT colonography. The recommended age and frequency of screening can be different depending on the risk level and the type of test.
Healthy Habits.
Eating a balanced diet, limiting red meat and processed meat, eating more fruits, vegetables, and fiber, avoiding smoking and excessive alcohol, maintaining a healthy weight, and being physically active can lower your risk of colorectal cancer.
Other Cancer Resources From Medspurs.
Article Sources.
Here are the sources I used to write this article on colorectal cancer:
- What Is Colorectal Cancer? | How Does Colorectal Cancer Start? | American Cancer Society
- Memorial Sloan Kettering Cancer Centerhttps://www.mskcc.org › types › c…Colon Cancer
- Wikipediahttps://en.m.wikipedia.org › wikiColorectal cancer
- MD Anderson Cancer Centerhttps://www.mdanderson.org › colo…What is Colorectal Cancer? Symptoms, Risk Factors & Treatments
- National Cancer Institute (.gov)https://www.cancer.gov › patientGastrointestinal Neuroendocrine Tumors Treatment (PDQ®)
- National Institutes of Health (NIH) (.gov)https://pubmed.ncbi.nlm.nih.gov › …Primary colorectal lymphomas
- National Cancer Institute (.gov)https://www.cancer.gov › patientGastrointestinal Stromal Tumors Treatment (Adult) (PDQ®)
- National Institutes of Health (.gov)https://pubmed.ncbi.nlm.nih.gov › …Leiomyosarcoma of the colon and rectum
- What Is Anal Cancer? | Types of Anal Cancer | American Cancer Society
- Centers for Disease Control and Prevention (.gov)https://www.cdc.gov › cancer › sta…Colorectal Cancer Statistics
- Colorectal Cancer Survival Rate: Understanding What It Means for You