Colorectal Cancer

Over 1.8 million new colorectal cancer cases and 881,000 deaths are estimated to occur in 2018, accounting for about 1 in 10 cancer cases and deaths. Overall, colorectal cancer ranks third in terms of incidence but second in terms of mortality.

Recent study has shown that Pakistan falls into a low incidence region/category for colorectal cancer. The crude incidence rate is 3.2% in both males and females. Most significantly, however, the incidence appears to be rising, particularly in males. This study also suggested that given an aging population, a strong tradition of consanguineous marriages, and a high prevalence of colorectal cancer risk factors, including a trend towards a more “westernized” dietary intake, this low incidence may, in fact, be an artifact. This data may also be an underestimation of colorectal cancer in Pakistan because the registry is voluntary and some cases may have gone unreported.

Your risk of getting colorectal cancer increases as you get older. More than 90% of cases occur in people who are 50 years old or older. Other risk factors include:

• Inflammatory bowel disease such as Crohn’s disease or ulcerative colitis.
• A personal or family history of colorectal cancer or colorectal polyps.
• A genetic syndrome such as familial adenomatous polyposis (FAP) or hereditary non-polyposis colorectal cancer (Lynch syndrome).

Lifestyle factors that may contribute to an increased risk of colorectal cancer include:

• Lack of regular physical activity.
• A diet low in fruit and vegetables.
• A low-fiber and high-fat diet.
• Overweight and obesity.
• Alcohol consumption.
• Tobacco use.

In most cases, people who have these symptoms do not have cancer. Still, if you have any of these problems, it is a sign that you should go to the doctor so the cause can be found and treated, if needed:

• A change in bowel habits, such as diarrhea, constipation, or narrowing of the stool, that lasts for more than a few days
• A feeling that you need to have a bowel movement that is not relieved by doing so
• Rectal bleeding
• Dark stools, or blood in the stool
• Cramping or abdominal (belly) pain
• Weakness and fatigue
• Unintended weight loss

Screening for colon cancer

Doctors recommend certain screening tests for healthy people with no signs or symptoms in order to look for early colon cancer. Finding colon cancer at its earliest stage provides the greatest chance for a cure. Screening has been shown to reduce your risk of dying of colon cancer.

People with an average risk of colon cancer can consider screening beginning at age 50. But people with an increased risk, such as those with a family history of colon cancer, should consider screening sooner. African-Americans and American Indians may consider beginning colon cancer screening at age 45.

Several screening options exist — each with its own benefits and drawbacks. Talk about your options with your doctor, and together you can decide which tests are appropriate for you. If a colonoscopy is used for screening, polyps can be removed during the procedure before they turn into cancer.

Diagnosing colon cancer

If your signs and symptoms indicate that you could have colon cancer, your doctor may recommend one or more tests and procedures, including:

• Using a scope to examine the inside of your colon. Colonoscopy uses a long, flexible and slender tube attached to a video camera and monitor to view your entire colon and rectum. If any suspicious areas are found, your doctor can pass surgical tools through the tube to take tissue samples (biopsies) for analysis and remove polyps.
• Blood tests: No blood test can tell you if you have colon cancer. But your doctor may test your blood for clues about your overall health, such as kidney and liver function tests.

Your doctor may also test your blood for a chemical sometimes produced by colon cancers (carcinoembryonic antigen or CEA). Tracked over time, the level of CEA in your blood may help your doctor understand your prognosis and whether your cancer is responding to treatment.

Staging colon cancer

Once you’ve been diagnosed with colon cancer, your doctor will order tests to determine the extent (stage) of your cancer. Staging helps determine what treatments are most appropriate for you.

Staging tests may include imaging procedures such as abdominal, pelvic and chest CT scans. In many cases, the stage of your cancer may not be determined until after colon cancer surgery.

The stages of colon cancer are:

• Stage I: The cancer has grown through the superficial lining (mucosa) of the colon or rectum but hasn’t spread beyond the colon wall or rectum.
• Stage II: The cancer has grown into or through the wall of the colon or rectum but hasn’t spread to nearby lymph nodes.
• Stage III: The cancer has invaded nearby lymph nodes but isn’t affecting other parts of your body yet.
• Stage IV: The cancer has spread to distant sites, such as other organs — for instance, to your liver or lung.

The type of treatment your doctor recommends will depend largely on the stage of your cancer. The three primary treatment options are surgery, chemotherapy and radiation.

Surgery for early-stage colon cancer

If your colon cancer is very small, your doctor may recommend a minimally invasive approach to surgery, such as:

• Removing polyps during a colonoscopy: If your cancer is small, localized and completely contained within a polyp and in a very early stage, your doctor may be able to remove it completely during a colonoscopy.
• Endoscopic mucosal resection: Removing larger polyps may require also taking a small amount of the lining of the colon or rectum in a procedure called an endoscopic mucosal resection.
• Minimally invasive surgery: Polyps that can’t be removed during a colonoscopy may be removed using laparoscopic surgery. In this procedure, your surgeon performs the operation through several small incisions in your abdominal wall, inserting instruments with attached cameras that display your colon on a video monitor. The surgeon may also take samples from lymph nodes in the area where the cancer is located.

Surgery for invasive colon cancer

If the cancer has grown into or through your colon, your surgeon may recommend:

• Partial colectomy: During this procedure, the surgeon removes the part of your colon that contains the cancer, along with a margin of normal tissue on either side of the cancer. Your surgeon is often able to reconnect the healthy portions of your colon or rectum. This procedure can commonly be done by a minimally invasive approach (laparoscopy).
• Surgery to create a way for waste to leave your body: When it’s not possible to reconnect the healthy portions of your colon or rectum, you may need an ostomy. This involves creating an opening in the wall of your abdomen from a portion of the remaining bowel for the elimination of stool into a bag that fits securely over the opening. Sometimes the ostomy is only temporary, allowing your colon or rectum time to heal after surgery. In some cases, however, the colostomy may be permanent.
• Lymph node removal: Nearby lymph nodes are usually also removed during colon cancer surgery and tested for cancer.

Surgery for advanced cancer

If your cancer is very advanced or your overall health very poor, your surgeon may recommend an operation to relieve a blockage of your colon or other conditions in order to improve your symptoms. This surgery isn’t done to cure cancer, but instead to relieve signs and symptoms, such as bleeding and pain.

In specific cases where the cancer has spread only to the liver but your overall health is otherwise good, your doctor may recommend surgery to remove the cancerous lesion from your liver. Chemotherapy may be used before or after this type of surgery. This approach provides a chance to be free of cancer over the long term.

Chemotherapy

Chemotherapy uses drugs to destroy cancer cells. Chemotherapy for colon cancer is usually given after surgery if the cancer has spread to lymph nodes. In this way, chemotherapy may help reduce the risk of cancer recurrence and death from cancer. Sometimes chemotherapy may be used before surgery as well, with the goal of shrinking the cancer before an operation. Chemotherapy before surgery is more common in rectal cancer than in colon cancer.

Chemotherapy can also be given to relieve symptoms of colon cancer that has spread to other areas of the body.

Radiation therapy

Radiation therapy uses powerful energy sources, such as X-rays, to kill cancer cells, to shrink large tumors before an operation so that they can be removed more easily, or to relieve symptoms of colon cancer and rectal cancer. Radiation therapy either alone or combined with chemotherapy is one of the standard treatment options for the initial management of rectal cancer followed by surgery.

Targeted drug therapy

Drugs that target specific malfunctions that allow cancer cells to grow are available to people with advanced colon cancer, including:

• Bevacizumab
• Cetuximab
• Panitumumab
• Ramucirumab
• Regorafenib
• Ziv-aflibercept

Targeted drugs can be given along with chemotherapy or alone. Targeted drugs are typically reserved for people with advanced colon cancer.

Some people are helped by targeted drugs, while others are not. Researchers have recently made progress in determining who is most likely to benefit from specific targeted drugs. Until more is known, doctors carefully weigh the possible benefit of targeted drugs against the risk of side effects and the cost when deciding whether to use these treatments.

Immunotherapy

Some patients with advanced colon cancer have a chance to benefit from immunotherapy with antibodies such as pembrolizumab and nivolumab. Whether a colon cancer has the chance to respond to these immunotherapies can be determined by a specific test of the tumor tissue.

Supportive (palliative) care

Palliative care is specialized medical care that focuses on providing relief from pain and other symptoms of a serious illness. Palliative care specialists work with you, your family and your other doctors to provide an extra layer of support that complements your ongoing care.

When palliative care is used along with all of the other appropriate treatments, people with cancer may feel better and live longer.

Palliative care is provided by a team of doctors, nurses and other specially trained professionals. Palliative care teams aim to improve the quality of life for people with cancer and their families. This form of care is offered alongside curative or other treatments you may be receiving.

Get screened for colorectal cancer: Screenings are tests that look for cancer before signs and symptoms develop. Colorectal screenings can often find growths called polyps that can be removed before they turn into cancer. These tests also can find colon or rectal cancer earlier, when treatments are more likely to be successful. The American Cancer Society recommends testing starting at age 45 for people at average risk.

Eat lots of vegetables, fruits, and whole grains: Diets that include lots of vegetables, fruits, and whole grains have been linked with a decreased risk of colon or rectal cancer. Eat less red meat (beef, pork, or lamb) and processed meats (hot dogs and some luncheon meats), which have been linked with an increased risk of colorectal cancer.

Get regular exercise. If you are not physically active, you have a greater chance of developing colon or rectal cancer. Increasing your activity may help reduce your risk.

Maintain healthy weight: Overweight or obese increases the risk of getting and dying from colon or rectal cancer. Eating healthier and increasing physical activity can help control weight.

Don’t smoke: Long-term smokers are more likely than non-smokers to develop and die from colon or rectal cancer.

Limit alcohol: Alcohol use has been linked with a higher risk of colorectal cancer. The American Cancer Society recommends no more than 2 drinks a day for men and 1 drink a day for women. A single drink amounts to 12 ounces of beer, 5 ounces of wine or 1½ ounces of 80-proof distilled spirits (hard liquor).

• https://www.cancercenter.com/colorectal-cancer/learning/
• Bray F, Ferlay J, Soerjomataram I, Siegel R, Torre L, Jemal A. Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA: A Cancer Journal for Clinicians. 2018;68(6):394-424.
• Bhurgri Y, Khan T, Kayani N, Ahmad R, Usman A, Bhurgri A, Bashir I, Hasan SH, Zaidi S. Incidence and current trends of colorectal malignancies in an unscreened, low risk Pakistan population. Asian Pac J Cancer Prev. 2011;12:703–708
• Ahmed F. Barriers to colorectal cancer screening in the developing world: The view from Pakistan. World J Gastrointest Pharmacol Ther. 2013;4(4):83-5.
• https://www.cdc.gov/cancer/colorectal/basic_info/risk_factors.htm
• https://www.cancer.org/latest-news/signs-and-symptoms-of-colon-cancer.html
• https://www.mayoclinic.org/diseases-conditions/colon-cancer/diagnosis-treatment/drc-20353674
• https://www.cancer.org/latest-news/six-ways-to-lower-your-risk-for-colon-cancer.html