Rectal cancer is often mistaken for colon cancer since both occur in adjacent parts of the digestive tract. However, rectal cancer has a higher risk of recurrence compared to colon cancer.
What is Rectal Cancer?
Rectal cancer is the development of cancerous cells in the rectum, which, along with the colon, forms part of the digestive system. Because of this close relationship, rectal and colon cancers are often collectively called colorectal cancer. As with most cancers, early detection and treatment are critical for better outcomes.
Causes and Risk Factors
The exact cause of rectal cancer remains unknown, but it generally involves the uncontrolled growth of abnormal cells that can invade and damage healthy tissue. Several factors may increase the risk of developing rectal cancer, including inherited genetic mutations such as hereditary nonpolyposis colorectal cancer (HNPCC or Lynch syndrome) and familial adenomatous polyposis (FAP). HNPCC significantly increases the risk of colon and other cancers, sometimes leading to preventive removal of the colon. FAP is a rare condition that causes numerous polyps in the colon and rectum, which can become cancerous. Additional risk factors include prior radiation therapy to the abdomen, as well as other medical conditions and lifestyle choices.
Symptoms of Rectal Cancer
Rectal cancer may not cause symptoms in its early stages, but as it advances, common signs can include rectal bleeding, changes in bowel habits, a persistent feeling of incomplete bowel emptying, pain during bowel movements, diarrhea or constipation, blood or mucus in the stool, unintentional weight loss, unexplained fatigue, and abdominal discomfort, gas, cramps, or pain. Additionally, iron-deficiency anemia”often caused by chronic blood loss”can also indicate rectal cancer.
Diagnosis of Rectal Cancer
Diagnosing rectal cancer usually involves multiple approaches, including physical examinations, screening procedures, colonoscopy, blood tests, and imaging studies. A physical exam may include a rectal examination to detect lumps or abnormalities. Screening tests, such as a fecal immunochemical test (FIT) or sigmoidoscopy, can help identify signs of cancer early. Blood tests may be used to check for anemia or tumor markers. Imaging techniques like endorectal ultrasound, CT scans, PET scans, and MRI are essential to determine the extent and stage of the cancer.
Stages of Rectal Cancer
Rectal cancer is staged based on how far it has spread and the progression of the disease. Staging helps determine the most appropriate treatment options depending on how far the disease has spread. The stages of rectal cancer include:
- Stage 0 (carcinoma in situ): Abnormal cells are found only in the innermost layer of the rectum wall.
- Stage 1: Cancer cells have spread beyond the innermost layer but have not reached the lymph nodes.
- Stage 2: Cancer cells have spread into or through the outer muscle layer of the rectum wall but not to
lymph nodes. In stage 2B, the cancer may have spread into the abdominal lining. - Stage 3: Cancer cells have spread through the outermost muscle layer of the rectum and to one or more lymph nodes. Stage 3 is further subdivided into substages based on the extent of lymph node involvement.
- Stage 4: Cancer cells have spread to distant sites, such as the liver or lungs.
Treatment Methods
Treatment for rectal cancer is tailored to several factors, including tumor size, cancer stage, patient age, and overall health. Common treatment options include surgery, radiation therapy, chemotherapy, targeted therapies, cryosurgery, radiofrequency ablation, stent placement, and palliative care to enhance quality of life. The choice of therapy varies by stage”for instance, stage 0 may only require removal of suspicious tissue during a colonoscopy, while stages 2 and 3 typically need a combination of surgery, radiation, and chemotherapy. Stage 4 treatment may involve multiple surgeries, radiation, chemotherapy, and targeted therapies. Participation in clinical trials is also an option, offering access to new and emerging treatments while contributing to scientific research.
* Liv Hospital Editorial Board has contributed to the publication of this content .
* Contents of this page is for informational purposes only. Please consult your doctor for diagnosis and treatment. The content of this page does not include information on medicinal health care at Liv Hospital .
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Frequently Asked Questions
Can rectal cancer be prevented?
Regular screenings, starting at age 45 or earlier depending on risk factors, can help detect colorectal cancer early. Adopting a healthy lifestyle, such as engaging in regular physical activity, avoiding smoking, and consuming a diet high in vegetables and fiber while limiting red and processed meats, can also help reduce the risk.
What is the survival rate for rectal cancer?
Advances in treatment have improved the overall outlook for rectal cancer. The 5-year survival rate for all stages combined is 67 %. However, survival rates vary depending on the stage of the cancer. For localized rectal cancer, the 5-year survival rate is 89 percent, while for regional and distant stages, it is 72 percent and 16 percent, respectively. It's important to note that these figures are based on data from 2010 to 2016, and current survival rates may differ.
Are there complications associated with rectal cancer?
Rectal cancer can spread to surrounding tissues, lymph nodes, and organs, increasing the risk of developing secondary cancers in areas such as the anus, colon, kidneys, lungs, small intestine, and vagina.