A Patient's Guide to Colon Cancer

The American Cancer Society estimates there will be more than 140,000 new cases of colorectal cancer diagnosed in the United States in 2018. That includes an estimated 97,220 new cases of colon cancer and 43,030 new diagnoses of rectal cancer. The ACS estimates that colorectal cancer deaths – the combined number from colon or rectal cancer – will claim the lives of more than 50,000 people in 2018. "This disease is preventable with early detection, and far fewer people would die of the disease if screening guidelines are followed," says Dr. Wafik El-Deiry, deputy cancer center director, Translational Research Program, Fox Chase Cancer Center in Philadelphia. El-Deiry is an American Cancer Society research professor.

Signs and Symptoms

These warning signs and symptoms are often missed, El-Deiry says. For example, bleeding might be attributed to hemorrhoids. In younger patients, some symptoms, such as bloody stools or abdominal pain, might be dismissed as not likely due to cancer, he says.

Types and Stages

Colorectal tumors can arise in any part of the colon or rectum. Typically, tumors that arise on the right side of the colon are caught later and have a worse prognosis than tumors that arise on the left side. Here are the four stages of the disease:

Stage 1 tumors have not invaded the wall of the bowel and typically can be removed at the time of colonoscopy by the physician conducting the procedure, who snips the growth. Stage 1 tumors include cancers that are part of a polyp, according to the ACS. This typically is a cure if no tumor cells are left behind. If the cancer in the polyp is high grade or there are cancer cells at the edges of the polyp, additional surgery may be needed, according to the ACS.

Stage 2 tumors are still located within the bowel wall or have gone through it but have not traveled to lymph nodes. When these tumors arise in the rectum, there is a general recommendation to treat with radiation therapy after the tumors are removed as this reduces the chance they will recur. Stage 2 colon tumors can be cured by surgery alone.

Stage 3 colorectal tumors involve tumor cells that have spread to lymph glands near the original tumor. These tumors are treated by surgery and chemotherapy as well as radiation for rectal tumors.

Stage 4 tumors are those that have spread to distant sites, including the liver, lungs, distant lymph nodes, the peritoneum (the space outside the bowels that if involved can lead to swelling of the abdomen) or other organs. Colon cancer is most likely to spread to the liver, while rectal cancer can spread to the lungs at advanced stages.

Treatments

Colon cancer is highly treatable if diagnosed early. Stage 1 tumors are often removed at the time of colonoscopy, while surgery is the main recommended therapy for stage 2 and 3 colorectal tumors. For stage 2 rectal tumors, in addition to surgery, radiation is typically recommended. Stage 3 colon tumors are treated with surgery, followed by about six months of chemotherapy. Patients with stage 3 rectal cancer are typically treated with radiation therapy before surgery and chemotherapy after surgery. For patients who receive radiation therapy, a low-dose chemotherapy pill is prescribed to help the radiation work better.

There are standard approved chemotherapy treatments for patients with stage 4 colorectal cancer, plus more specific treatments being developed to treat certain types of tumors.

Knowing the genetic subtype of the tumor – determined via a tissue sample, biopsy or blood sample – can provide useful information. For patients who have an advanced disease that has spread and for which there are no available treatments, clinical trials present one option. Close monitoring of the response to available treatments and finding out what's driving the tumor or its resistance to the available therapies can also be helpful in uncovering more treatment options. It's important to have such discussions with specialists who can explain and prioritize the various options based on all of the available information.

Health Care Providers That Treat Colorectal Cancer

Risk Factors

There's a genetic component in about 15 percent of cases of colorectal cancer, El-Deiry says. Patients with a family history of colon cancer or polyps are at increased risk of colorectal cancer. This includes people with a family history of familial polyposis, or FAP, a genetic condition in which a person develops multiple polyps inside his or her colon as early as the teenage years, according to the National Institutes of Health. If these polyps aren't removed, they'll become cancerous. People with a history of inflammatory bowel disease are also at increased risk of colorectal cancer.

Eating a diet high in red meat, such as beef, lamb or pork and some luncheon meats, increases the risk for developing colorectal cancer, says Dr. Scott Strong, surgical director of the Digestive Health Center at Northwestern Memorial Hospital in Chicago.

Maintaining healthy eating and exercise habits can help prevent colon cancer. Drinking in moderation and refraining from smoking are also helpful preventive approaches.

Screening

The American Cancer Society recommends screening for colorectal cancer starting at age 50. At this age, the average man has a 25 to 30 percent risk of a precancerous polyp, says Dr. Hardeep Singh, a gastroenterologist with St. Joseph Hospital in Orange, California. For women, the risk is 15 to 20 percent. People with a family history of colorectal cancers are advised to get screened at age 40, or 10 years before the age at which their family member developed cancer. There are several screening options the cancer society recommends, including colonoscopy.

During a colonoscopy, a doctor uses a colonoscope – a long, flexible tube-like instrument, about a half-inch in diameter – to examine the colon. The physician inserts the colonoscope through the rectum and advances it to the other end of the large intestine. Before the procedure, an anesthesiologist sedates the patient with medication that's administered intravenously. During the colonoscopy, which typically lasts 30 to 60 minutes, the doctor can examine the colon for abnormalities, like polyps. The doctor can remove these growths and examine whether they're cancerous.

Other screening methods include fecal occult blood testing and a virtual colonoscopy.

Despite ACS guidelines, many people don't get screened or put it off. It's important to get screened; if caught early, colorectal cancer is highly treatable. If the disease is discovered after it's spread to the lymph glands or distant organs like the lungs or liver, it's no longer curable in most people. "Most colon cancers are either preventable or treatable, especially when caught in early stages," says Dr. Arti Lakhani, an oncologist/hematologist at the AMITA Health Cancer Institute in the Chicago area. "By combining [colorectal] screenings, a healthy diet and active lifestyle, we can stay one step ahead in the fight against cancer."