Rectal Cancer

What is Rectal Cancer?

Rectal cancer is a type of cancer that forms in the tissues of the rectum, which is the last part of the large intestine before reaching the anus. It typically starts as small growths called polyps on the inner lining of the rectum and can spread to other parts of the body if left untreated.

How Rectal Cancer Develops

Rectal cancer can originate from various types of polyps, the most common being adenomatous polyps, also known as adenomas. Over time, some of these cells within polyps can accumulate genetic mutations that cause them to become cancerous. Factors that may contribute to the development of rectal cancer include age, family history, diet, and lifestyle choices such as smoking or heavy alcohol use.

Certain inherited conditions like Lynch syndrome, also known as Hereditary Nonpolyposis Colorectal Cancer (HNPCC), or familial adenomatous polyposis (FAP) can also contribute to Rectal Cancer concerns.

Types of Rectal Cancer

There are different types of rectal cancer, depending on the type of cells that are affected. These include:

  • Adenocarcinomas: These are the most common type of rectal cancer, accounting for about 95% of cases. They form in glandular cells that produce mucus to lubricate the inner lining of the rectum.
  • Carcinoid tumors: These are rare, slow-growing tumors that form in the hormone-producing cells of the rectum.
  • Gastrointestinal stromal tumors (GISTs): These are rare and can develop in the rectum’s muscle or connective tissue layers.


Early stages of rectal cancer may not have any noticeable symptoms. As the cancer progresses, common signs and symptoms may include:

  • Blood in the stool or bleeding from the rectum
  • Persistent change in bowel habits, like diarrhea or constipation
  • Abdominal pain or discomfort
  • Feeling of incomplete bowel movement
  • Unexplained weight loss

If you experience any of these symptoms, it is important to consult a doctor for further evaluation and potential diagnosis.

Diagnosis of Rectal Cancer

Rectal cancer is diagnosed through a combination of clinical evaluation and diagnostic tests. Physicians often start with a detailed medical history and perform a physical examination, which may include a digital rectal exam (DRE). Diagnostic tests typically follow and can include:

  • Colonoscopy: A procedure allowing doctors to view the entire colon and rectum with a camera-equipped flexible tube and, if needed, to take tissue samples or remove polyps.
  • Flexible Sigmoidoscopy: Similar to a colonoscopy, it only examines the lower part of the colon.
  • Biopsy: The removal of a small tissue sample for examination under a microscope to determine if cancer cells are present.
  • Imaging Tests: This could include a Computerized Tomography (CT) scan, Magnetic Resonance Imaging (MRI), or Ultrasound to ascertain the extent of cancer and whether it has spread.

Early detection and diagnosis are crucial in the management and treatment of rectal cancer, often improving the likelihood of a successful treatment outcome.

Risk Factors

While the exact causes of rectal cancer are still unknown, certain risk factors may increase a person’s chances of developing it. These include:

  • Age: Rectal cancer is more common in older adults, with the average age at diagnosis being 63.
  • Personal or family history: Having a personal history of colon or rectal polyps or inflammatory bowel disease (IBD) or a family history of colorectal cancer can increase the risk.
  • Lifestyle factors: A diet high in red and processed meats, low in fruits and vegetables, and lack of physical activity may increase the risk.
  • Smoking and alcohol consumption: These habits have been linked to an increased risk of developing rectal cancer.
  • Obesity: Being overweight or obese can also increase the risk of developing rectal cancer.


Treatment for rectal cancer depends on the stage and location of the cancer, as well as a person’s overall health.

There is a variety of specific treatments used to combat rectal cancer, categorized based on the stage and individual patient factors:

  • Surgery: Approaches vary from local excision for early-stage cancer to more extensive operations like Total Mesorectal Excision (TME) for advanced cases.
  • Chemotherapy: Drugs can be used to shrink tumors before surgery or to eliminate any remaining cancer cells post-operatively.
  • Radiation Therapy: Often combined with chemotherapy, this treatment can reduce the size of tumors and kill cancer cells, using high-energy rays.
  • Targeted Therapy: Focuses on specific genes and proteins involved in cancer growth, suited for certain types of rectal cancer.
  • Immunotherapy: A newer form of treatment that helps the immune system recognize and attack cancer cells more effectively.

Each of these treatments may be used alone or in combination, depending on a variety of factors, including the cancer’s specific characteristics and the patient’s preferences and overall health.


While there is no guaranteed way to prevent rectal cancer, there are steps that can be taken to reduce the risk:

  • Regular screening: It is recommended to start colorectal cancer screening at age 50 for average-risk individuals, and earlier for those with risk factors or a family history.
  • Healthy lifestyle choices: Eating a balanced diet rich in fruits, vegetables, and whole grains, maintaining a healthy weight, and staying physically active can lower the risk of developing rectal cancer.
  • Quitting smoking and limiting alcohol consumption: These habits have been linked to an increased risk of colorectal cancer, so avoiding or reducing them can help lower the risk.

What Happens If Left Untreated

If rectal cancer is left untreated, the consequences can be severe and potentially life-threatening. Cancer cells can continue to grow and multiply, which may lead to the tumor increasing in size and invading nearby organs and tissues. Without intervention, the cancer might also spread to distant parts of the body—a process known as metastasis—which can affect the liver, lungs, and other areas.

This progression can cause further complications, hinder the functionality of affected organs, and significantly reduce a patient’s quality of life. Ultimately, without treatment, rectal cancer can be fatal. Individuals must seek prompt medical attention if they experience any symptoms or are at an elevated risk for colorectal cancers.