Colorectal Cancer

Colon and rectal cancer are cancers that involve the lowest part of the digestive system: the large intestine and the rectum.Tests that monitor or screen for colorectal cancer are important tools in finding colon and rectal cancer at an early stage.

COLORECTAL CANCER SYMPTOMS

The most common symptoms of colon and rectal cancer include:

• Stomach pain or frequent gas pains
• Change in bowel habits
• Blood in the bowel movements
• Feeling weak or tired
• Low iron level (iron deficiency anemia)
• Black or dark-colored stools

COLORECTAL CANCER DIAGNOSIS

A colonoscopy is often used to look inside the rectum and large intestine. Cancers growing within the large intestine and rectum can be seen during a colonoscopy, and a biopsy can be done, confirming the presence of a cancer.

Staging

Once a colorectal cancer is diagnosed, the next step is to determine its stage. Staging is a system used to describe the aggressiveness and spread of a cancer. The stage of a colorectal cancer is assigned based on:

• Whether there are signs of cancer spread on a physical exam, CT scan, or MRI of the abdomen and pelvis, chest X-ray, or other imaging tests.
• The appearance of the cancer specimen when viewed under the microscope, after it has been removed with surgery.

Colorectal cancer stages range from stage I (cancer has invaded into but not through the entire wall of the intestine), to stage IV (the cancer has spread to distant organs, such as the liver). Treatment depends on disease stage.

Earlier stages of disease (stages I through III) are referred to as localized colorectal cancers and generally treated with surgery, with or without chemotherapy.

Stage IV cancer is called advanced colorectal cancer and is generally treated with chemotherapy; some patients may benefit from surgery of the primary tumor and sometimes of metastases. Treatment of stage IV disease is covered elsewhere.

COLON CANCER TREATMENT

The treatment of colon cancer usually involves surgery, and it may also involve chemotherapy; radiation therapy is only rarely needed.

Surgery

The initial treatment of colon cancer usually involves surgery.During the surgery, the cancerous part of the colon and surrounding tissues are removed. The lymph nodes within this surrounding tissue are examined under a microscope to determine if the cancer has spread beyond the colon.

In most people, the two ends of the colon can be reconnected immediately after the cancerous part has been removed. If this can be done, it means that you will continue to have bowel movements normally, through your rectum and anus.

Chemotherapy

Chemotherapy is a treatment given to slow or stop the growth of cancer cells. Even after a colon cancer has been completely removed with surgery, cancer cells can remain in the body, increasing the risk of the cancer coming back. In some people, chemotherapy can eliminate these cancer cells and increase the chance of cure.

• In some cases, the benefits of chemotherapy (better chance of survival) clearly outweigh the possible risks (chemotherapy side effects like diarrhea, vomiting, hair loss, nerve damage, or more serious risks). Not everyone will have these side effects.
• In other cases, the benefit of chemotherapy is not worth the risks.

RECTAL CANCER TREATMENT

Most rectal cancers are treated with a combination of surgery, radiation therapy, and chemotherapy; as with colon cancers, treatment is chosen based upon disease stage.

• Stage I rectal cancer — Surgery alone may cure the cancer.
• Stage II and III — Chemotherapy and radiation therapy are typically recommended along with surgery; in general, the chemotherapy and radiation are given before surgery with additional chemotherapy given after surgery.
• Stage IV — Predominantly treated with chemotherapy, with or without surgery.

 

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