Rectal cancer is oftenly confused with colon cancer because they are both in the same part of the body. However, rectal cancer has a higher chance of recurrence than colon cancer.
What is Rectal Cancer?
Rectal cancer, as the name suggests, refers to the cancerous cells development in the rectal area. The rectum and colon are both part of the digestive system, so they are often grouped together under the term colorectal cancer. Per usual for cancer, early detection and treatment are crucial for better outcomes.
Causes and Risk Factors
The exact cause of rectal cancer is still unknown, but it involves the uncontrolled growth and multiplication of cancerous cells, which can invade and destroy healthy tissue. Certain factors can increase the risk of developing rectal cancer, including inherited gene mutations like hereditary nonpolyposis colorectal cancer (HNPCC or Lynch syndrome) and familial adenomatous polyposis (FAP). HNPCC significantly raises the risk of colon and other cancers, and in some cases, removing the colon may be recommended as a preventive measure. FAP is a rare disorder that causes polyps to develop in the lining of the colon and rectum, which can become malignant. Another risk factor is radiation therapy to the abdomen. Other conditions and lifestyle factors such can also increase the risk of rectal cancer.
Symptoms of Rectal Cancer
Rectal cancer may initially be asymptomatic, but as it progresses, common symptoms may include rectal bleeding, changes in bowel habits, a 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. Iron-deficiency anemia can also be a sign of rectal cancer due to blood loss.
Diagnosis of Rectal Cancer
Diagnosis typically involves a combination of physical exams, screening tests, colonoscopy, blood tests, and imaging tests. Physical exams may include a rectal exam to feel for lumps, while screening tests such as a fecal immunochemical test (FIT) or sigmoidoscopy may be recommended. Blood tests and imaging tests like endorectal ultrasound, CT or PET scans, and MRI can help 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
The choice of treatment for rectal cancer depends on various factors, mainly on tumor size, spread of cancer, age, and general health. Treatment options may include surgery, radiation therapy, chemotherapy, targeted therapies, cryosurgery, radiofrequency ablation, stent placement, and palliative therapy to improve overall quality of life. The specific treatment approach for each stage of rectal cancer may vary. For example, stage 0 may involve the removal of suspicious tissue during a colonoscopy, while stages 2 and 3 may require surgery, radiation therapy, and chemotherapy. Stage 4 may involve surgery in multiple areas of the body, along with radiation therapy, chemotherapy, and targeted therapies. Clinical trials are also available as an option and can provide access to innovative treatments and help advance scientific understanding.
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 percent. 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.