Lymphoma of the Colon and Rectum

Lymphoma of the colon and rectum is a less common form of colorectal cancer and one that is associated with a significant absence of symptoms.

Lymphomas can develop in other parts of the body outside of the lymphatic system because lymphoid tissue can be found throughout the body. As such, 40 percent of lymphomas occur outside of the lymphatic system, most often in the gastrointestinal tract. One of the manifestations is colorectal lymphoma.

This article will discuss colorectal lymphoma, symptoms and diagnosis, and treatment options.

Understanding Colorectal Lymphoma

Colorectal lymphoma accounts for 15 to 20 percent of gastrointestinal lymphomas (compared to 50 to 60 percent in the stomach and 20 to 30 percent in the small intestine). What differentiates gastrointestinal lymphomas from all other types is the often complete lack of characteristic symptoms.

Examples include:

• The lack of enlarged lymph nodes on physical examination.
• The lack of enlarged lymph nodes on X-ray.
• The lack of abnormal blood cell values or bone marrow abnormalities.
• The lack of an abnormal spleen or liver.

Some or all of these things would be expected in a "classic" case of lymphoma. Not so with gastrointestinal lymphoma.

Symptoms and Diagnosis

Colorectal lymphoma is typically seen more in people over 50, as well as those with inflammatory bowel disease (IBD), and persons with severely compromised immune systems. Most involve a type of lymphoma called non-Hodgkin lymphoma (NHL).

Symptoms usually develop only after the formation of a tumor, by which time a person may experience symptoms like:

• Abdominal pain.
• Unexplained weight loss of more than 5 percent.
• Lower gastrointestinal bleeding and/or bloody stools.

Unlike other cancers affecting the colon or rectum, there is rarely any bowel obstruction or perforation of the bowel since the tumor itself will be pliable and soft. Most colorectal lymphomas are identified using either a computerized tomography (CT) scan or a double-contrast barium enema with X-ray.

Because of the late presentation of symptoms, half of all colorectal lymphomas are discovered at stage 4 disease, when cancer will have likely spread to other organs. Tumors that have metastasized are inherently more difficult to treat.

Treatment

Treatment of colorectal lymphoma is typically the same as any other manifestations of NHL. Depending on the cancer stage, it may involve:

• Chemotherapy administered as infusions into the veins.
• Radiotherapy used to suppress the formation of new tumors (although the treatment is associated with high rates of complications).
• Surgery to remove the primary tumor (if the cancer has yet not metastasized).

In most cases, a combination of surgical resection and chemotherapy will be used. Surgical resection involves the removal of the section of the colon with cancer, the ends of which are then reattached with sutures.

When used together, surgery and chemotherapy have been shown to increase survival times by anywhere from 36 to 53 months. In cases where metastasis has only affected one organ (as opposed to multiple organs), the practice has resulted in 83 percent of patients living for 10 years or more.

With surgery alone, relapse rates are high (74 percent), with a greater likelihood of death due to widespread (disseminated) disease. As such, chemotherapy is considered a must to better ensure longer survival times. Without it, recurrence typically occurs within five years.