Expert Advice on Colon Cancer Treatment and Prevention Learn About Colonoscopies, Precancerous Polyps and More

Colon cancer often has no symptoms, and can go undetected for years. The good news? It’s also one of the most slow-growing cancers, so with proper colonoscopies and screening, it’s highly preventable. To mark Colorectal Cancer Awareness Month, a gastrointestinal oncologist explains risk factors, tests and options for treatment... Colon cancer isn’t a subject most people are eager to think about, much less discuss with loved ones or doctors. But each year in the U.S., more than 145,000 people are diagnosed with colorectal cancer and approximately 50,000 people die of the disease. “It’s a very common form of cancer that remains under-diagnosed mainly because not enough people get screened for it,” says Veena Shankaran, M.D., an oncologist who specializes in gastrointestinal cancers at Fred Hutchinson Cancer Research Center in Seattle. But the news on colon cancer isn’t all bad. A 2009 report released by a group of leading cancer organizations revealed that from 1975 to 2000, colorectal cancer incidence rates dropped 22% and death rates dropped 26%. “Colon cancer is highly treatable, regardless of its stage,” adds Shankaran, who is also an assistant professor of medical oncology at the University of Washington School of Medicine, in Seattle. “Ten years ago, we really didn’t have many options for colon cancer treatment, but now there are a lot of different therapies, and survival rates for even advanced, or metastatic, cancer are improving,” she says. In this exclusive Lifescript interview, Shankaran discusses colon cancer treatment, symptoms and causes. Who is at risk for colon cancer? Many people mistakenly believe that colon cancer is mainly a disease of older white men. But while colon cancer is slightly more common in men, gender differences in colon cancer diagnoses are relatively small. Many primary care physicians are proactive about making sure women get regular breast cancer screenings, but they may not necessarily be doing the same for colon cancer. Colon cancer risk does increase with age. That’s because it can take 10 years or more for a precancerous polyp to form and then eventually grow into a cancer. Your family's history of colon cancer affects your risk of developing colon cancer. Some people, who are genetically predisposed to developing colon cancer, may be diagnosed at a younger age. However, when a young person develops colon cancer it’s not always due to genetics. What are the symptoms of colon cancer? Many people who have precancerous polyps or colon cancer have no symptoms. But the most common symptoms include rectal bleeding, abdominal pain, bloating, unexplained weight loss, and a change in bowel habits – someone who is normally very regular may suddenly develop chronic constipation, or the stools become much narrower. Can colon cancer be prevented? Yes, colon cancer is highly preventable. In fact, the best way to screen for colon cancer – a test called a colonoscopy – is also the best way to prevent it. Most colon cancers develop over time from precancerous polyps. During the procedure, the doctor can find and remove these polyps early on before cancer develops. This is why screening colonoscopiesarea vital part of routine health maintenance in asymptomatic patients. The standard recommendation is to begin having colonoscopies at age 50 and repeat the test every 10 years. But if you have a family history of colon cancer – meaning a parent, sibling or child has been diagnosed with the disease – we recommend you begin having colonoscopies 10 years before the age at which your family member was diagnosed. And if you were diagnosed with colon cancer, it’s important to ask your physician how your diagnosis affects how and when your children or siblings should be screened. How is a colonoscopy done? The doctor inserts a flexible tube into your colon to view the lining of the colon and to look for polyps or cancerous growths. Colonoscopies are outpatient procedures, so you’ll be able to go home after the procedure is finished. Many patients worry that it will be painful, but sedation is given to minimize pain and discomfort, and the procedure lasts only about 20-30 minutes. Does it matter whether a primary care physician or a specialist performs a colonoscopy? It doesn’t really make a difference, as long as you go to someone who performs the test regularly. If you live in a part of the country where there aren’t many G.I. specialists, then you’re probably going to see a family physician or other primary care doctor. Can other tests detect colon cancer? Colonoscopies are the gold standard, because the precancerous polyps can be removed at the same time that you’re being screened, but it’s not the only option. There’s also a fecal occult blood test, which you can do at home to look for signs of blood or other abnormalities in the stool. Another screening test is called a flexible sigmoidoscopy, which is similar to a colonoscopy except that it only examines the rectum and the lower portion of the colon. This test is recommended every five years. One of the newest tests is the CT colonography, also known as a virtual colonoscopy, which involves a series of X-rays of the colon. The main disadvantage of virtual colonoscopies is that if you find precancerous polyps, you can’t remove them at the same time. If the doctor finds a lot of polyps in your colon, you may need to have more frequent screening tests to remove them before they develop into cancer. How does colon cancer treatment work? Depending on the stage of colon cancer, treatment can involve surgery, chemotherapy and/or radiation. If colon cancer is localized, meaning it hasn’t metastasized or spread to any other organs, then a patient typically has surgery first to remove the tumor, followed by chemotherapy to help reduce the chances of the cancer recurring. When the cancer has spread to other organs, then we often recommend starting with chemotherapy to slow the disease progression and help people feel better. Unless the primary tumor is causing bothersome symptoms, we usually don’t recommend surgery first. In many cases, the liver is the first place the colon cancer spreads, so we may recommend liver-directed therapy, meaning that either chemotherapy or radiation beads are injected directly into the blood vessels near the liver to attack the cancer. When I see a patient who has metastatic cancer, of course they’re going to be scared, but I tell them that though we can’t cure their cancer, we hope to prolong their life and improve the quality of that life too. I also encourage patients to ask their physicians if they would be candidates for a clinical trial. Clinical trials can provide opportunities for novel treatment approaches and ultimately will improve our understanding and ability to treat these kinds of cancers more effectively. If a patient has surgery, do they always need an ostomy? This is a common misconception that patients have about surgical colon cancer treatment. Most patients with colon cancer will never need an ostomy at any point during their treatment. However, depending on the clinical situation, an ostomy may be necessary either on a temporary basis, while part of the colon heals, or possibly on a permanent basis. But even if the ostomy is permanent, with proper supplies and instruction, patients with ostomies can continue their normal activities including exercise, swimming, sex, travel and work. What do you think are the biggest recent advances in colon cancer treatment? For all kinds of cancers, we are learning more about how certain molecular characteristics of a person's cancer can influence which chemotherapy drugs are likely to be effective. In the last few years, we’ve learned that a specific mutation (KRAS), which occurs in about 40% of colon cancers, can confer resistance to certain types of chemotherapy drugs, namely cetuximab and panitumumab. It may seem like disappointing news, but knowing this in advance can help us save patients from getting therapy that isn’t going to help them, and instead allow them to quickly pursue other options, such as clinical trials. How Much Do You Know About Colon Cancer? It’s been more than a decade since Katie Couric helped raise awareness about colon cancer by having her colonoscopy televised and shown on the “Today Show.” But experts say too many Americans are still unaware of their colon cancer risk or are misinformed about the best ways to protect themselves.