Rectum, Cancer of: Symptoms, Causes & Treatment

Introduction to Rectal Cancer

Rectal cancer is a type of colorectal cancer that starts in the rectum, the last several inches of the large intestine. The rectum is responsible for storing stool before it is eliminated from the body. When abnormal cells grow and form a tumor in the rectal tissue, it can lead to rectal cancer. According to the American Cancer Society, rectal cancer is the second most common type of colorectal cancer, accounting for about 1 in 3 cases.

Symptoms of Rectal Cancer

Common symptoms of rectal cancer include:

• Rectal bleeding or blood in the stool
• Changes in bowel habits, such as constipation or diarrhea
• Abdominal discomfort or cramping
• Feeling of incomplete bowel emptying
• Fatigue and weakness
• Unexplained weight loss

It’s important to note that these symptoms can also be caused by other conditions, such as hemorrhoids or inflammatory bowel disease. If you experience any of these symptoms persistently, it’s essential to consult with a healthcare provider for proper diagnosis.

Causes and Risk Factors

The exact cause of rectal cancer is not fully understood, but several factors can increase the risk of developing the disease:

• Age: The risk of rectal cancer increases with age, with most cases diagnosed in individuals over 50.
• Family history: Having a family member with colorectal cancer or certain inherited genetic syndromes, such as Lynch syndrome or familial adenomatous polyposis (FAP), can increase the risk.
• Personal history of polyps or inflammatory bowel disease: Individuals with a history of colorectal polyps or conditions like Crohn’s disease or ulcerative colitis have a higher risk of developing rectal cancer.
• Lifestyle factors: A diet high in red and processed meats, lack of physical activity, obesity, smoking, and heavy alcohol consumption can all contribute to an increased risk of rectal cancer.

Diagnosis of Rectal Cancer

If rectal cancer is suspected based on symptoms or risk factors, several diagnostic tests may be performed:

• Digital rectal exam (DRE): A doctor inserts a gloved, lubricated finger into the rectum to feel for any abnormalities.
• Colonoscopy: A thin, flexible tube with a camera is inserted into the rectum and colon to visually inspect for polyps or tumors. If any suspicious areas are found, a biopsy can be taken for further analysis.
• Imaging tests: CT scans, MRI, or endorectal ultrasound may be used to determine the extent of the cancer and if it has spread to nearby organs or lymph nodes.
• Blood tests: Carcinoembryonic antigen (CEA) levels may be checked, as elevated CEA can be a marker for rectal cancer.

Staging of Rectal Cancer

If rectal cancer is diagnosed, the next step is to determine the stage of the cancer. Staging helps doctors plan the most appropriate treatment and assess the prognosis. The TNM staging system is commonly used:

• T (Tumor): Indicates the size and extent of the primary tumor.
• N (Nodes): Describes if the cancer has spread to nearby lymph nodes.
• M ( Metastasis): Specifies if the cancer has metastasized to distant organs.

Based on the TNM classification, rectal cancer is assigned a stage from 0 to IV, with stage 0 being the earliest and stage IV being the most advanced.

Treatment Options

Treatment for rectal cancer depends on various factors, including the stage of the cancer, the patient’s overall health, and personal preferences. Common treatment options include:

• Surgery: The primary treatment for rectal cancer is often surgery to remove the cancerous portion of the rectum and surrounding lymph nodes. Surgical techniques include local excision for early-stage tumors, low anterior resection, or abdominoperineal resection for more advanced cases.
• Radiation therapy: Radiation may be used before surgery to shrink the tumor or after surgery to reduce the risk of recurrence. It can also be used as a palliative treatment to relieve symptoms in advanced cases.
• Chemotherapy: Chemotherapy drugs may be given before or after surgery to destroy cancer cells and reduce the risk of recurrence. In some cases, chemotherapy may be combined with radiation therapy (chemoradiation).
• Targeted therapy: Targeted drugs, such as bevacizumab or cetuximab, may be used to specifically target and inhibit the growth of cancer cells with certain genetic mutations.
• Immunotherapy: Immunotherapy drugs, such as pembrolizumab or nivolumab, can help the body’s immune system recognize and attack cancer cells.

A multidisciplinary team of specialists, including surgeons, medical oncologists, and radiation oncologists, work together to develop an individualized treatment plan for each patient.

Prevention of Rectal Cancer

While not all cases of rectal cancer can be prevented, certain lifestyle modifications and screening measures can help reduce the risk:

• Regular screening: Colonoscopy is the most effective screening tool for detecting and removing precancerous polyps before they develop into cancer. The U.S. Preventive Services Task Force recommends regular screening starting at age 45 for average-risk individuals.
• Healthy diet: Eating a diet rich in fruits, vegetables, and whole grains while limiting red and processed meats may help lower the risk of rectal cancer.
• Physical activity: Engaging in regular physical activity and maintaining a healthy weight can reduce the risk of rectal cancer.
• Avoiding tobacco and excessive alcohol: Quitting smoking and limiting alcohol intake can help decrease the risk of developing rectal cancer.

Prognosis and Survival Rates

The prognosis for rectal cancer depends on various factors, including the stage at diagnosis, the patient’s overall health, and response to treatment. According to the National Cancer Institute’s SEER database, the overall 5-year relative survival rate for rectal cancer is 67.3%. However, survival rates are significantly higher when the cancer is caught and treated in its early stages.

Regular screening, early detection, and advancements in treatment options have contributed to improved outcomes for individuals with rectal cancer. It’s important for patients to work closely with their healthcare team to develop a personalized treatment plan and follow-up care to monitor for any signs of recurrence.

If you have any concerns about rectal cancer or are experiencing symptoms, don’t hesitate to speak with your healthcare provider. Early detection and prompt treatment can make a significant difference in the outcome of rectal cancer.