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The American Cancer Society (ACS) estimates that there will be 106,180 new cases of colon cancer and 44,850 new cases of rectal cancer in the United States in 2022. Colorectal cancer is the third most common cancer in the U.S. And among cancers that affect all sexes, it is the second leading cause of death. The incidence varies around the world. It is more common in countries with a higher economic status, but according to a 2021 analysis, it is more likely to affect people with low incomes. Fatality rates have fallen due to medical advances. And, as the 2021 analysis observes, numbers of diagnoses in people younger than 50 are rising, possibly due to improvements in screening. Below, learn about the symptoms and treatments of colorectal cancer. Also, find out about the risk factors. A person can take steps to limit some of them. Symptoms Share on PinterestVadym Terelyuke/Getty ImagesColorectal cancer may not cause symptoms in the early stages. If it does, they may include:changes in bowel habitsdiarrhea constipationa feeling that the bowel does not empty fullyblood in feces that makes it look dark brown or blackbright red blood from the rectumabdominal pain and bloatingfeeling full, even when a long time has passed since a mealfatigue or tirednessunexplained weight lossanemia If a doctor finds signs of anemia during a routine medical check, they may suggest screening for colorectal cancer. Or, they may diagnose it during routine screening. Around 40% of people with this type of cancer receive the diagnosis when the disease is in an early stage. The symptoms can be similar to those of many other health conditions. Anyone with concerns about these symptoms should seek medical advice. Early signs Among people who receive a diagnosis of colorectal cancer after reporting symptoms:37% have blood in feces or from the rectum34% have abdominal pain23% have anemia Among those who receive the diagnosis after seeking emergency medical care:57% have a blockage in their bowel25% have peritonitis, or inflammation of the stomach lining18% have a perforation, or hole, in their bowel Some people only notice symptoms in the later stages, when the cancer has spread to the lungs, liver, or other areas. The symptoms can depend on the area affected. If cancer spreads to the liver, a person may have jaundice, which causes yellowing of the whites of the eyes. If a person has white or light brown skin, it may also appear yellowish. If cancer affects the lungs, it can cause difficulty breathing or a cough. Causes and risk factors The cause of colorectal cancer is unclear, but it likely stems from a combination of genetic and environmental factors. According to research from 2022, around 70% of cases develop for no clear reason, while 10% seem to result from inherited syndromes, and 20% happen in family clusters. Some other colorectal cancer risk factors may include:being over the age of 50being malehaving a low incomehaving a diet low in fiber and high in animal protein, saturated fats, and calorieshaving a diet high in red or processed meatsconsuming alcoholsmokinghaving low levels of physical activitybeing overweight or having obesityhaving inflammatory bowel diseasehaving type 2 diabeteshaving certain genetic featureshaving had breast, ovary, or uterine cancerhaving undergone radiation therapy for abdominal cancer in childhoodhaving polyps in the colon or rectum Polyps are sometimes precancerous. Learn about one type, called sessile polyps, that can develop in the colon. Increased risk among Black Americans Research from 2018 concludes that Black Americans are more likely to develop and die from colorectal cancer than any other group of people in the U.S. As the ACS report, the chance of having this type of cancer is at least 20% higher for Black people than for white people, and the fatality rate is 40% higher for Black people. The ACS cites socioeconomic factors and inequity in screening and other aspects of healthcare, as well as inequity in employment, diet, and other factors related to daily life. The authors of the 2018 analysis say that identifying whether colorectal cancer affects Black people in distinct ways requires further research. They add that this type of investigation might lead to more effective treatment. What is health inequity? Learn more here. Screening The American College of Physicians recommends regular screening for people who:have a personal or family history of colorectal cancerare Black Americans aged 45 years or overare not Black, over 50, and have an average riskhave Crohn’s disease, Lynch syndrome, or adenomatous polyposis A doctor will recommend a specific screening schedule. For example, they may recommend a stool test every 2 years and a colonoscopy or sigmoidoscopy every 10 years. People should also be aware of the differences between precancerous lesions and polyps and cancerous polyps.Everyone aged 50 or older has a risk of developing precancerous lesions or polyps. A colonoscopy is the gold-standard approach to removing these. During the procedure, a doctor can also check for cancerous polyps. Diagnosis Screening can detect polyps before they become cancerous. It can also detect colon cancer in the early stages, when it is easier to treat. In 80% of cases, a doctor diagnoses colorectal cancer after performing a colonoscopy because the person has symptoms. Routine screening detects 11% of cases, and 7% of people with colorectal cancer receive a diagnosis after seeking emergency care for sudden abdominal symptoms. The following are the most common screening and diagnostic procedures for colorectal cancer. Colonoscopy A colonoscopy is the gold-standard diagnostic tool for colorectal cancer. It has a high level of accuracy and can show precisely where a tumor is. The procedure involves using a long, thin, flexible tool called a colonoscope that contains a light and a camera. It allows the doctor to see the whole colon and rectum. They may remove polyps or take a sample of tissue, a biopsy, for testing during the procedure. A colonoscopy is painless, but some people take a mild sedative to help them stay calm. A person may also need to drink a laxative fluid to empty colon beforehand. Bleeding and perforation of the colon wall are rare but possible complications. Blood stool test This test checks for blood in a stool sample. Many conditions can cause blood in stool, and a positive result does not necessarily mean that cancer is present. Stool immunochemistry Also known as a fecal occult blood test, this checks for hidden blood in the lower colon. It involves using a small kit to collect a stool sample at home. What are some other causes of rectal bleeding? Stool DNA test This test checks for several DNA markers that colon cancer or precancerous polyps shed into stool. A person collects an entire bowel movement at home for testing in a lab. If the result is positive, a colonoscopy is necessary. It is worth keeping in mind that this test cannot detect every DNA marker of cancer. Flexible sigmoidoscopy This procedure involves using a sigmoidoscope, a flexible, thin, lighted tube, to examine the rectum and sigmoid colon — the last part of the colon before the rectum. The test takes a few minutes and is not painful, but it might be uncomfortable. There is a small risk of perforating the colon’s wall. Barium enema X-ray Barium is a contrast dye that can reveal any unusual features on an X-ray. A healthcare professional introduces it into the bowel as an enema. A doctor may recommend a colonoscopy for closer investigation following a barium enema X-ray. CT colonography This produces images of the colon. It is less invasive than a colonoscopy, but if it reveals a mass, the person needs a colonoscopy. Imaging scans Ultrasound, CT, or MRI scans can show if cancer has spread to another part of the body. Treatment The best approach to treatment for colorectal cancer depends on several factors. These include:the size and location of tumors and the cancer’s stagewhether the cancer is recurrentthe person’s overall health Options include chemotherapy, radiation therapy, and surgery. Also, palliative care can help manage the symptoms, such as pain, and improve the quality of life. Surgery Surgery is the primary treatment for colorectal cancer that is limited to the colon. It aims to remove cancerous tissue, including tumors and affected lymph nodes, and prevent the cancer from spreading. The surgeon usually reconnects the bowel after removing cancerous areas, but they may need to create a stoma for drainage into a colostomy bag. This is often temporary. Surgery may remove all traces of early stage cancer. In the later stages, surgery cannot stop the cancer from spreading, but removing a blockage can help ease any symptoms. Surgery for colon cancer may be open, involving a large incision. It may instead be laparoscopic, a less invasive type of surgery that requires tiny incisions. The surgeon typically uses robotic devices during the surgery. The most common types of colon cancer surgery include: Local excision This involves removing early cancerous tissues. During the procedure, a surgeon removes polyps and some colon tissue. Colectomy A colectomy involves removing some or all of the colon. If the surgery is partial, the surgeon reattaches the remaining segments. Other names for this approach are a hemicolectomy, a partial colectomy, or a segmental resection. A total colectomy involves removing the whole colon. This is less common, and a surgeon may only recommend it if there are many polyps, for example. Removing blockages Sometimes a cancerous growth blocks all or a portion of the colon. When this happens, a surgeon may place a stent to open the colon. If a stent will not work or the blockage is serious, they may perform a colectomy and connect one end of the remaining portion of the colon into a stoma through which stool can flow. Chemotherapy Chemotherapy drugs destroy cancerous cells throughout the body. This may help treat colon cancer or shrink a tumor before surgery. It can also help relieve symptoms in the later stages. This approach, however, can have widespread adverse effects, as it affects both cancerous and healthy cells. Targeted therapy This involves taking drugs that target specific proteins to slow or prevent the growth of cancerous cells. The adverse effects are usually less severe than those of chemotherapy because these drugs only target cancerous cells. Immunotherapy This drug-based treatment helps the immune system detect and eliminate cancerous cells. It may benefit some people with advanced colorectal cancer. Possible adverse effects include an autoimmune reaction, in which the body mistakenly attacks its own cells. Radiation therapy This involves using high-energy beams of radiation to destroy cancerous cells and prevent them from multiplying. A doctor may recommend it to help shrink a tumor before surgery for rectal cancer. They may also use it alongside chemotherapy, in an approach known as chemoradiation. It can have long- and short-term adverse effects. Ablation Ablation involves using microwaves, radiofrequency, ethanol, or cryosurgery to destroy a tumor without removing it. A surgeon delivers the therapy using a probe or needle guided by ultrasound or CT imagery. Palliative and end-of-life care If colorectal cancer spreads to organs beyond the colon, progressing to stage 4, it is not possible to cure it. Other options may include:surgery to remove a blockageradiation therapy or chemotherapy to reduce the size of tumorspain relieftreatment for side effects of medicationcounselinghospice care Stages The “stage” of cancer refers to how far it has spread. Determining the stage helps doctors choose the most appropriate treatment. There are different guidelines for staging. One set of guidelines is:Stage 0: This is the earliest stage, also known as carcinoma in situ. The cancer is only in the inner layer of the colon or rectum.Stage 1: The cancer has grown through the inner layer of the colon or rectum but has not spread beyond the wall of the rectum or colon.Stage 2: The cancer has grown through or into the wall of the colon or rectum but has not yet reached nearby lymph nodes.Stage 3: The cancer has reached nearby lymph nodes but not other parts of the body.Stage 4: The cancer is present in other parts of the body, such as the liver or lungs. Sometimes, treatment eliminates the cancer but it comes back in the same area or another one. This is called “recurrent” cancer. Outlook The outlook for someone with colorectal cancer depends on different factors, including their age, their overall health, and the stage of the cancer at diagnosis. The ACS provides 5-year survival rates. These reflect the likelihood of living for at least another 5 years after the diagnosis, compared with a person who does not have colorectal cancer. The ACS gives survival rates using these stages:Local: The cancer has stayed in its original location.Regional: The cancer has spread to nearby tissues.Distant: It has reached more distant parts of the body. This table shows the estimated 5-year survival rates for a person with colon cancer.Stage5-year survival rateStage 1 (local)91%Stage 2 (regional)72%Stage 3 (distant)14%Overall64% This table shows the estimated 5-year survival rates for a person with rectal cancer:Stage5-year survival rateStage 1 (local)90%Stage 2 (regional)73%Stage 3 (distant)17%Overall67% Here, learn more about the life expectancy for people with stage 4 colon cancer. Prevention Colorectal cancer can affect anyone, and it is not possible to prevent it. However, taking some steps may help reduce the risk. Nutrition Dietary measures that may help include:eating plenty of fiber, fruits, and vegetableslimiting the intake of red and processed meats.opting for healthy fats, such as from avocados, olive oil, fish oils, and nuts, rather than saturated fats Exercise and weight Moderate, regular exercise may help lower the risk of colorectal cancer. Exercise can also help reduce the risk of obesity, which is linked with colorectal and other cancers. Aspirin Experts have found that taking aspirin may help reduce the risk in some people, but speak with a doctor about this first. Vaccines Researchers are investigating the potential for vaccines to prevent colorectal cancer. One option that has been successful in mice is a vaccine that stops polyps from becoming cancerous. This might, one day, benefit people with a high risk. Summary Colorectal cancer is a leading cause of cancer-related death. Treatment in the early stages can remove cancerous cells and increase the likelihood of a positive outcome. It is important to take any signs of colorectal cancer seriously. They can also indicate other potentially severe health problems. However, symptoms of this cancer may not appear until the later stages. Anyone with a risk of developing colorectal cancer should ask a doctor about screening. Having regular screening improves the chances of an early diagnosis. Last medically reviewed on April 7, 2022Colorectal CancerCancer / OncologyGastroIntestinal / GastroenterologyMedically reviewed by Youssef (Joe) Soliman, MD — By Yvette Brazier and Zawn Villines on April 7, 2022 Latest newsWhat sets 'SuperAgers' apart? Their unusually large neuronsOmega-3 may provide a brain boost for people in midlifeSeasonal affective disorder (SAD): How to beat it this fall and winterCDC: Monkeypox in the US 'unlikely to be eliminated in the near future'Why are more women prone to Alzheimer's? 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