Guide to Colorectal Cancer (Colon Cancer & Rectal Cancer)

Reviewed by the physicians of Columbia’s Colorectal Surgery Team, March 2024

Colorectal cancer is a term used to describe cancers of the lower part of the digestive system, the colon and rectum. It is one of the most common and aggressive cancers, but also one of the most preventable and treatable.

Key Info

Colorectal cancer can progress without causing any symptoms
Screening tests like colonoscopy help catch polyps and early cancers before they get too big
Surgery can treat colorectal cancer by removing the section of the digestive tract where the tumor is located

What is Colon Cancer?

Colon cancer is a cancer of the digestive system that starts in the colon (or large intestine). Colon cancer is the third-most-common cancer in the United States amongst both women and men, and the lifetime risk of developing colon cancer is approximately 1 in 20 (5%). Over 90 percent of cases occur after the age of 50, and in most cases, colon cancer develops slowly over many years. If diagnosed at an early stage, colon cancer is potentially curable.

What is Rectal Cancer?

Rectal cancer is cancer of the rectum: the last six inches of the digestive system that sits between the colon (large intestine) and the anus. Colon cancer and rectal cancer share many similarities, and the two are commonly referred to as ‘colorectal cancer’.

How does Colorectal Cancer Start?

Most colorectal cancers begin as a polyp, which is a growth of tissue on the lining of the colon or rectum that grows larger and can erode through the wall of the intestine. Not all polyps are dangerous, but they should be removed to make sure there is no cancer present, and/or prevent the conversion of a polyp into a cancer.

Risk Factors

You may be at increased risk if:

You or a close relative have had colon polyps or colon cancer
You have a history of inflammatory bowel disease (Crohn's Disease or Ulcerative Colitis)
You have certain genetic syndromes, like familial adenomatous polyposis (FAP) or hereditary non-polyposis colon cancer (also known as Lynch syndrome)

Symptoms

Don’t wait for symptoms to develop as colorectal cancers often do not produce any symptoms until late in the disease. Symptoms include changes in bowel habits for more than a few days; feeling the need to have a bowel movement even after having just had one, rectal bleeding, cramping or abdominal pain, weakness and fatigue, and unexpected weight loss.

Prevention & Screening

The best way to prevent colorectal cancer is examining the large intestine by colonoscopy. The death rate from colon and rectal cancers has been declining over the past two decades because of the increase in prevalence of screening and early prevention. The American Cancer Society recommends that people at average risk for colorectal cancer have a screening test (colonoscopy or other type) beginning at age 45. The five-year survival rate for colorectal cancer now stands at about 90 percent when the cancer is found and treated early. Men and women with certain colon or rectal cancer risk factors should speak with their doctors about starting screening at a younger age and possibly being screened more often than people at average risk.

Colorectal cancer screening is important because most patients with early stage cancer do not have any symptoms. Patients with colorectal cancers surgically removed at an early stage have a greater chance of being cured than those whose cancers are detected at a later stage.

All men and women over the age of 45 should be screened for colorectal cancer regardless of family or personal risk factors. A number of tests are available to screen for colon polyps or cancer.

The following may be used alone or in combination with each other:

Fecal Occult Blood Test (FOBT) – This test checks for occult (hidden) blood in the stool.
Flexible Sigmoidoscopy – This test examines the inside of the rectum and lower portion of the colon through a flexible, lighted tube. The doctor may remove polyps and collect samples of tissue or cells for closer examination.
Colonoscopy – Colonoscopy is used to detect precancerous colon polyps before they become cancerous. In this examination, a doctor looks at the inside of the rectum and entire colon through a flexible, lighted tube. The doctor may remove polyps and collect samples of tissue or cells for closer examination.
Double Contrast Barium Enema – The patient is given an enema containing a dye (barium), followed by an injection of air. X-rays of the rectum and colon are then taken. The barium outlines the intestine on the x-ray film, so that polyps and other abnormalities may be easily seen.
Virtual Colonoscopy (CT Colonography) – This test involves performing a special CT Scan (or CAT Scan) which specifically examines the colon and rectum for polyps and tumors. Just like a traditional colonoscopy, this test requires that you cleanse the colon the day prior with a bowel preparation solution (taken orally).

Diagnosis

Colorectal cancer is often diagnosed with colonoscopy. During a colonoscopy, your doctor examines the inside of the rectum and entire colon through a flexible, lighted tube. Confirmation of the diagnosis can only be made by taking a sample (biopsy) of the potentially cancerous tissue for examination by a pathologist.

Treatment

The primary treatment for cancers of the colon and rectum is surgery. For cancers that have not spread, surgery alone often provides a cure.

Depending on the location and stage of your cancer, your doctor may recommend chemotherapy and/or radiation therapy either before or after surgery.

Surgical Options for Colorectal Cancer

Endoscopic/endoluminal resection: If cancer is confined within a polyp that can be completely removed through the colonoscope, no other therapy may be necessary. This is called an endoscopic or endoluminal resection. However, follow up colonoscopies at 1 to 3 year intervals are advised.

Colectomy/proctectomy: In many cases, depending upon the location and extent of the cancer, removal of the portion of the colon or rectum containing the cancer is required. This is known as a “colon resection” or “colectomy.” When a colon or rectal resection is required, between 8 to 12 inches of colon are usually removed; the exact length will vary from patient to patient, but the goal is always to remove the entire segment of colon that contains the cancer. The segment's adjoining mesentery (a membrane that connects the intestine to the abdomen and which contains blood vessels and lymph nodes), is also removed. This is because colon cancers can involve the lymph nodes and invade the blood vessels directly.

The procedure can be performed either laparoscopically/robotically (using small incisions and special miniaturized instruments) or via an open surgery called laparotomy.

Laparoscopic surgery: Laparoscopic surgery is the standard of care for the majority of colorectal procedures. Compared to open surgery, the benefits of laparoscopy include: less postoperative pain and therefore less pain medication, faster healing for a quicker return home, and smaller, less noticeable scars. During laparoscopic surgery, the surgeon utilizes a small incision through which a "port" is placed to inflate the abdominal cavity with gas. A camera is then introduced through the port to help visualize the inside of the abdominal cavity on a television monitor. Surgery is performed with instruments through additional ports placed via small incisions in the abdominal wall.
Robotic Surgery: During robotic surgery, the surgeon sits at a console that includes a large, high definition computer screen and controls to manipulate the surgical instrumentation. Across the room at the operating table, narrow arms with tiny surgical tools and a miniature camera are inserted through two to four tiny incisions in the patient’s abdomen. From the console, the surgeon has an excellent magnified view and can move the instrumentation to carefully perform each step of the operation. All of the colorectal surgeons at Columbia are trained in the use robotic technology for the surgical treatment of colon and rectal cancer as well as other non-cancerous conditions.

Anastomosis: After the segment is removed, the two remaining ends of the bowel are joined together to reconnect the intestine. This reconnection is called an anastomosis.

The only tumor location that prohibits anastomosis is the very distal rectum, within a finger's reach of the anus. Patients with tumors in this uncommon location have a number of treatment options available, including surgery, chemotherapy and radiation therapy. Our surgical team is specialized in complex procedures such as intersphincteric proctectomy, colonic J pouch, and coloplasty, which often allow preservation of the sphincter and minimize the need for a permanent ostomy even in difficult situations.

While colorectal tumors frequently can be removed without the need for a permanent ostomy, some patients may unfortunately require a complete rectal resection, also called an abdomino-perineal resection, and a permanent colostomy, which is a small opening, or stoma, in the abdominal wall through which feces exits the body.

If a stoma is necessary, specially trained nurses, in addition to your physician, will assist in its initial care. Today this is simpler than in the past. The stoma nurse is a professional trained in the care and teaching of patients requiring colostomy. He or she is available for questions before and after your surgery at NewYork-Presbyterian/Columbia, and is an invaluable source of information, medical care and support.

Advanced And Recurrent Cancer

Even colon or rectal cancer that invades other nearby structures (locally advanced cancer) or comes back (recurrent cancer) but has not spread in many distant sites may be curable, provided the tumor can be removed with clear margins (“clearance”). Removal of locally advanced or recurrent cancer poses special challenges and needs specific expertise. When such tumors are surgically resected, a portion or entirety of the adjacent involved organ may need to be removed to achieve clearance. Special care is taken to preserve the function of other organs in the vicinity.

In some instances with extensive cancers, our surgeons work collaboratively with radiation oncologists to administer radiation (intraoperative radiation (IORT)) or chemotherapy (intraperitoneal chemotherapy) at the time of surgery. These techniques help precisely target the radiation or chemotherapy directly to the specific area(s) of the cancer in the abdomen and pelvis, allowing for the direction of maximal dosage to the cancer while minimizing collateral damage to other organs that sometimes occurs with conventional external treatment. The Columbia surgeons and oncologists have extensive experience with these techniques that are available at few other centers.

Colorectal Cancer With Distant Spread: When colorectal cancer spreads to distant locations in the body, the pieces of tumor deposited elsewhere are called metastases. In several instances, even colorectal cancer with distant spread can be managed with surgery in conjunction with other therapies. Our colorectal surgeons work closely with world-class hepatic surgeons for liver metastases and thoracic surgeons for lung metastases who are able to remove the tumors in these sites in addition to the primary tumor in the colon and rectum. A multidisciplinary team consisting of these surgeons, radiation oncologists and medical oncologists works together to determine the best strategy and the timing of the various therapies and surgery individualized to each patient to attempt a cure even in these challenging situations.

FAQs about Colon and Rectal Surgery

Once it has been determined that I have a growth in my colon or rectum, will I need additional diagnostic studies?

If your problem was diagnosed using a digital rectal exam, or through fecal occult blood testing (Hemoccult® test), you will need additional evaluation, most likely by colonoscopy, which examines the entire colon and rectum, or, at least, by sigmoidoscopy, which examines the final two feet of the colon and the rectum. These examinations are important not only to determine the extent of the current problem, but also to look for other abnormalities, which might also be present and could influence your best course of treatment. Your physician will determine which test is best for you.

Prior to having surgery on my colon or rectum, will I need any additional preoperative evaluation?

A variety of laboratory examinations, including chest X-ray, EKG, CBC (complete blood count), chemistries, coagulation parameters, are routinely required. If you are anemic or there is risk for significant blood loss, a sample of your blood will be held at the blood bank to expedite replacement blood in your type if transfusion becomes necessary. A CT or CAT scan of the abdomen and pelvis may be ordered by your physician. This study can help to evaluate the local or metastatic (spread) of any cancer. For rectal cancers, a transrectal ultrasound, which determines the depth of a tumor and possible lymph node involvement, can also help in determining the best treatment options. Other special studies may be dictate by your general state of health. For example, if you have emphysema, a pulmonologist may be consulted and perform pulmonary function tests or an arterial blood gas. Your surgeon will evaluate the necessity of such studies.

Prior to my sigmoidoscopy or colonoscopy, or colorectal surgery, will I require any special bowel preparation?

So that the lining of the colon can well-visualized during colonoscopy, it is necessary to remove the stool using laxatives taken by mouth. Popular choices include GoLytely®, Nulytely®, Fleet® Phosphosoda, and Magnesium Citrate. Preparation for sigmoidoscopy, a test that views only the lower portion of the colon, is routinely done with enemas (often, Fleet® enemas). Your physician will choose a regimen which will allow the most comfort while appropriately cleansing your colon. Preparation for an abdominal colon resection or rectal excision requires that your colon be cleansed of stool and bacteria. This cleansing allows for a safer anastomosis (joining of two pieces of bowel), and decreases the incidence of wound infection. Your physician will choose the appropriate regimen for you, which may include oral antibiotics such as erythromycin, neomycin, or ciprofloxacin. It is very important that, whichever plan is established, you follow the prescription completely. If you are unable to complete the plan, your surgery may need to be cancelled or rescheduled. Please call your physician's office with any problems.

What is a stoma, and will I need one?

A stoma, commonly referred to as a colostomy or ileostomy, is an artificial opening in the abdomen created during surgery that allows elimination of stool after the operation. It is necessary if passage to the anus is interrupted after the operation. The colostomy may be temporary, to give the colon a chance to heal, or permanent (in 10 to 15 percent of cases) if the lower part of the rectum has been removed. In most cases, if a stoma will be permanent, your surgeon will be able to tell you this prior to the procedure. However, if your anastomosis (rejoining of the bowel) is low, or there are other factors encountered during the operation that cause your surgeon to be concerned about your safety, a temporary stoma may be required. This "protecting" or "diverting" stoma may be in the form of a colostomy or ileostomy brought to the skin's surface before the anastomosis, thus allowing time for healing without being bathed by stool and bacteria. The stoma may be closed or reconnected at a later date, after healing of your anastomosis has taken place. This healing is confirmed by a radiologic study, such as a gastrograffin enema, and/or by direct visualization, which will view the lining and may offer an opportunity to dilate a narrowed ("strictured") area. Caring for a stoma is enhanced by specially-trained nurses called "enterostomal" therapists. They help teach you about stoma care, skin care, and appliance management. They can also introduce you to other patients with stomas ("stomates") so that you can learn from their experiences. Thanks to the expertise of our team, even patients who have otherwise been counselled as needing a permanent ostomy (external ‘bag’) at other centers might be candidates for alternatives that maintain continence and ensure normal intestinal continuity.

How will my pain be managed after the surgery?

In the immediate postoperative period, you will receive some form of analgesia which you can control, termed Patient Controlled Anesthesia ("PCA"). This may be a device with a button you push to deliver intravenous medication to yourself, or in the form of an epidural catheter, with the same opportunity to self-administer additional pain medication. The epidural catheter is similar to that placed in women who are in labor and is very safe. It seems to block the input of pain sensation, and therefore, if effective, will block the response to pain. Once you are able to take pain medicine by mouth, these other methods will be removed. Interim forms of pain management include intravenous or intramuscular injections given by the nursing staff.

How long will I need to stay in the hospital after my surgery?

The length of hospital stay varies depending on the individual and the type of surgery. In general, the length of stay ranges from 4 to 10 days. Most surgeons will keep their patients in the hospital until they can take food and pain medicine by mouth, are urinating, and having bowel movements. Individual practices may vary, so this issue should be discussed with your surgeon prior to your surgery. Special needs or concerns (for example, in the elderly who require assisted living) may require that special arrangements be made prior to the surgery. These concerns should be discussed with your physician, family and friends well in advance so that proper arrangements can be made.

How will the diagnosis of colon or rectal cancer affect my family?

It is common that a diagnosis of cancer may both frighten and upset your family. However, there are now several therapeutic options available to patients, and these should be discussed at length with your surgeon and with your family prior to making final decisions. Letting your family know will give them time to adjust, and help you make decisions in a time when your own decision-making processes may be more difficult. Additionally, if it appears that you have a family history of colon, ovarian, endometrial, gastric, or pancreatic cancer, it is important for your family members to be screened as well. Colon cancer, as mentioned above, may be preventable in its early stages.

Preparing for your First Appointment

If you have recently had any imaging studies performed, such as an MRI or CT scan, it is very important to bring a copy of the study as well as the imaging report. The findings of your imaging study will help your physician decide if you need a procedure and if so, what kind. If you have had the imaging study performed at NewYork-Presbyterian Hospital/Columbia University Irving Medical Center, we will be able to access the reports internally. However, if your imaging study was performed at an outside facility, we strongly encourage you to obtain a copy of the images and accompanying report ahead of time to bring with you to your consultation. If you do not have these items with you, we may have to request them directly from the facility that performed the study. That extra step can delay your diagnosis and treatment.

Before your first appointment, please download and print the following two forms, fill them out, and bring them with you to your appointment.

Authorization Form For Release Medical Records
Registration Form (English | Español )

Next Steps

If you or someone you love is in need of care for a colorectal issue, we’re here to help. Our team is available for consultations, second opinions, and to perform any colorectal procedure, should one be necessary. Call us at (212) 342-1155 or request an appointment online.

Our colorectal surgeons have the highest level of expertise in endoscopic and surgical procedures for colorectal cancer. Our experience with technological innovations such as robotic surgery and transanal endoscopic microsurgery (TEMS) allows for a minimally invasive approach in many circumstances, with the possibility of organ preservation in some instances. Our surgeons have earned national and international recognition for their expertise in minimally invasive and laparoscopic surgery, and routinely train other surgeons across the country. Our overall surgical outcomes are highly favorable compared to national averages.

Surgical expertise allows wide resection of even locally advanced cancers while preserving normal structures and function thus maintaining quality of life. Given their experience in complex and reoperative abdominal and pelvic surgery, our surgeons have a special expertise in techniques that avoid a permanent ostomy (external bag) even for advanced and very low rectal and other rare cancers related to the intestine, colon and rectum.

Efforts are constantly underway to streamline the care of colorectal cancer with a simultaneous emphasis on promoting a positive experience and support for patients and their family members. The appointment of a Nurse navigator dedicated to the care of patients with colon and rectal cancer is unique to Columbia University Irving Medical Center. As the point of immediate contact, this liaison helps to streamline appointments for the optimal investigation, management and follow-up of patients with colorectal cancer and provides resources for the support of patients and families dealing with the difficulties of a diagnosis of colorectal cancer.