GET THE FACTS

The colon and rectum are parts of the body’s digestive system and together form a long, muscular tube called the large intestine. The colon is the first 6 feet of the large intestine and the rectum is the last 8-10 inches. Treatment approaches differ between cancers of the colon or rectum and are, therefore, discussed separately. The treatment of colon cancer typically consists of surgery and/or chemotherapy and may involve several physicians, including a gastroenterologist, a surgeon, a medical oncologist and other specialists.

Care must be carefully coordinated between the various treating physicians involved in managing the cancer. Colon cancer begins in polyps (growths inside of the colon). The cells that line the polyps undergo mutations (gene changes) that lead to cancer. If not detected early, the cancer may invade adjacent organs and spread through the lymph and blood systems throughout the body to the liver, lungs and other organs.

Pathology Report

Most cancer patients will undergo a biopsy or other procedure to remove a sample of tissue for examination by a pathologist in order to diagnose their disease. A pathologist is a physician specializing in the diagnosis of disease based on examination of tissues and fluids removed from the body. Upon examination, the pathologist determines if the tissue sample contains normal, pre-cancerous or cancerous cells and then writes a report with his or her findings. The ensuing report is called a pathology report and is used by the primary doctor in conjunction with other relevant tests or X-rays to make a final diagnosis and determine a treatment strategy. By having a basic understanding of what the pathologist is looking for and the structure of the report, you may better understand your pathology report. Having a copy of your pathology report for your personal records is highly recommended. Your primary doctor should be able to address specific questions you have about your pathology report.

Staging: Determining the stage of the cancer or the extent of the spread requires a number of tests and is ultimately confirmed by surgical removal of the cancer and exploration of the abdominal cavity. The following tests may be used to look for cancer in the chest, abdomen and pelvis.

Computed Tomography (CT) Scan: A CT scan is a technique for imaging body tissues and organs, during which X-ray transmissions are converted to detailed images, using a computer to synthesize X-ray data. A CT scan is conducted with a large machine positioned outside the body that can rotate to capture detailed images of the organs and tissues inside the body. This method is more sensitive and precise than an X-ray.

Magnetic Resonance Imaging (MRI): MRI uses a magnetic field rather than X-rays, and can often distinguish more accurately between health and diseased tissue. MRI gives better pictures of tumors located near bone than CT, does not use radiation as CT does, and provides pictures from various angles that enable doctors to construct a three-dimensional image of the tumor.

Colonoscopy: Because 3-5% of patients with a colon cancer can already have an additional cancer in their colon, colonoscopy is routinely recommended to identify whether a second cancer is present in the colon prior to surgery. During a colonoscopy, a long flexible tube that is attached to a camera is inserted through the rectum, allowing physicians to examine the internal lining of the colon for polyps or other abnormalities. Patients are given medication to minimize discomfort. The physician may perform a biopsy in order to collect samples of suspicious tissues or cells for closer examination.

Ultrasound: Ultrasound is a technique that uses sound waves to differentiate tissues based on varying tissue density.

PET/CT Scan: Positron emission tomography–computed tomography (better known by its acronym PET-CT or PET/CT) is a medical imaging technique using a device which combines both a positron emission tomography (PET) scanner and an x-ray computed tomography (CT) scanner, so that images acquired from both devices can be taken sequentially, in the same session, and combined into a single superposed image.

Surgery: Upon completion of the clinical staging evaluation, surgery is performed to remove the cancer along with part of the normal adjacent colon and determine the level of spread within the colon and abdomen. Surgery is performed through an abdominal incision or through a laparoscope. Laparoscopic surgery is less invasive and involves the insertion of surgical instruments through very small incisions in the abdomen

Stages

Stage 1

Overview

Following colon cancer surgery, the cancer is classified as a Stage I colon cancer if the final pathology report shows that the cancer is confined to the lining of the colon. Stage I cancer does not penetrate the wall of the colon into the abdominal cavity, has not spread to any adjacent organs or local lymph nodes and cannot be detected in other locations in the body.

Stage 2

Overview

Following surgical removal of colon cancer, the cancer is referred to as Stage II if the final pathology report shows that the cancer has penetrated the wall of the colon into the abdominal cavity, but does not invade any of the local lymph nodes and cannot be detected in other locations in the body.

Adjuvant Chemotherapy

The delivery of cancer treatment following local treatment with surgery is referred to as “adjuvant” therapy and may include chemotherapy, radiation therapy, and/or targeted therapy.

Stage 3

Overview

Following surgical removal of colon cancer, the cancer is classified as Stage III if the final pathology report shows that the cancer has spread to the lymph nodes but not to distant sites in the body. The following is a general overview of treatment for Stage III colon cancer. Treatment may consist of surgery, chemotherapy, targeted therapy (drugs which act by a different mechanism than chemotherapy to target tumor cells) and/or radiation. Multi-modality treatment, which is treatment using two or more techniques, is increasingly recognized as an important approach aimed at cure or prolongation of survival.

Adjuvant Chemotherapy

The delivery of cancer treatment following local treatment with surgery is referred to as “adjuvant” therapy and may include chemotherapy, radiation therapy, and/or targeted therapy. Adjuvant chemotherapy is administered to patients with Stage III colon cancer for the purpose of reducing the

Stage 4

Overview

Colon cancer is classified as Stage IV if the cancer has spread to distant locations in the body; this may include the liver, lungs, bones, distant lymph nodes or other sites. While it is commonly thought that patients diagnosed with Stage IV colon cancer have few treatment options, certain patients can still be cured of their cancer, and others can derive significant benefit from additional treatment.

Patients with Stage IV colon cancer can be broadly divided into two groups:

  • Those with widespread, metastatic cancer that cannot be treated with surgery (sometimes called unresectable cancer)
  • Those with cancer that has metastasized to a single site

When the site of metastasis is a single organ (such as the liver), and the cancer is confined to a single defined area within the organ, patients may benefit from local treatment directed at that single metastasis, which may include surgery, or other liver-directed techniques such as radiofrequency ablation, radiation, embolization, or cryotherapy.

The following is a general overview of treatment for Stage IV colon cancer. Treatment may consist of surgery, radiation, chemotherapy, targeted therapy, or a combination of these treatment techniques. Multi-modality treatment, which is treatment using two or more techniques, has become an important approach for increasing a patient’s chance of cure or prolonging survival. In some cases, participation in a clinical trial utilizing new, innovative therapies may provide the most promising treatment. Circumstances unique to each patient’s situation may influence how these general treatment principles are applied.

Clinical trials

New chemotherapy drugs continue to be developed and evaluated in patients with recurrent cancers in clinical trials. The purpose of a phase I clinical trial is to evaluate the safety of new drugs in order to determine the best way of administering the drug. The purpose of a phase II clinical trial is to investigate whether the drug has any anticancer activity in patients. For more information on clinical trials, go to www.clinicaltrials.gov.

Recurrent Colon Cancer

When colon cancer has returned following an initial treatment with surgery, radiation therapy, and/or chemotherapy or has stopped responding to treatment, it is said to be recurrent or relapsed.

Patients with recurrent colon cancer can be broadly divided into two groups:

  • 1 Persons with cancer that can be surgically removed with the goal of a cure
  • 2 Persons with more widespread cancer

Colon cancer may metastasize to the liver, lung, or other locations. When the site of metastasis is a single organ, such as the liver, and the cancer is confined to a single defined area within the organ, patients may benefit from local treatment directed at that single metastasis. The majority of patients have unrespectable or widespread disease. Historically, treatment outcomes for these patients were poor. However, new combinations of chemotherapy drugs and use of targeted therapies have improved outcomes.