At age 68, Rosemary Karkosak of Boyne City had no reason to suspect she might have colon cancer, but she scheduled a colonoscopy anyway.

Weighing partly on her mind was the story of a family friend’s daughter, who in her mid-30s thought the symptoms she was experiencing were related to child birth rather than the colon cancer diagnosis that came instead.

Karkosak recently underwent a colonoscopy as a screening measure, and her test results came back clear. It was an educated decision, despite a lack of family history of colorectal cancers or any symptoms; doctors say early screening saves a vast majority of lives affected by cancers of the colon and rectum.

“It was quick,” Karkosak said of the procedure. “It went great, with no problems at all, and I don’t have to have another one for 10 years.”

She did say that because of a history of reaction to anesthesia, she was more concerned about that aspect than the actual exam itself. “I was awake during the procedure and medicated so that you’re aware of what’s going, but you don’t feel any discomfort,” she offered as advice for others considering colonoscopy.

She also added, “I have to complement the staff at the hospital’s endoscopy department. They were so pleasant and they explained everything so thoroughly.”

Dr. Heidi Huck, gastroenterologist with Great Lakes Digestive Health Associates in Petoskey, performed the colonoscopy on Karkosak. Below, she discusses colorectal cancers in light of March’s designation nationally as Colorectal Cancer Awareness Month:

Sensitive subject, serious disease

News-Review: Where are colorectal cancers found?

Dr. Huck: Colorectal cancers are found in the colon and rectum. The colon is also called the large intestine. It is a long, muscular tube that absorbs water and salts and packages waste for evacuation at a socially appropriate time. The rectum is the last segment of the colon.

PNR: How prevalent are colorectal cancers?

Dr. Huck: Colorectal cancer is the third most common cancer diagnosed in the U.S. and the second leading cause of cancer death. It affects men and women equally. In 2008, it was estimated that 148,810 men and women would be diagnosed with colorectal cancer and 49,960 would die from the disease. By age 50, all U.S. citizens are at average risk for developing colorectal cancer. This risk increases with age.

PNR: Is it becoming more prevalent, and if so, is that because of an increase in cancer incidents, an increase in screening and awareness, or both?

Dr. Huck: The incidence of colorectal cancer is decreasing in individuals who undergo colorectal screening. Regrettably, at least half of U.S. adults are not receiving regular age- and risk-appropriate screening or may never have been screened. Regular colonoscopy is estimated to decrease the risk of developing colorectal cancer by 60-70 percent.

PNR: How is colorectal cancer detected?

Dr. Huck: Once colorectal cancer has developed it can be detected by imaging the colon with colonoscopy or X-ray. Additionally, fecal tests for blood or DNA from cancer cells will identify some cancers. Ideally, regular screening of asymptomatic individuals would identify individuals at risk before cancer develops. The surest way to prevent cancer death is to prevent cancer from developing at all.

PNR: Are there any signs or symptoms associated with colorectal cancer?

Dr. Huck: Bleeding, change in usual bowel habit, change in stool caliber and weight loss are all symptoms of colorectal cancer. However, early colorectal cancer may have no symptoms whatsoever.

PNR: When should screenings begin for men and women?

Dr. Huck: For optimal screening, I recommend colonoscopy every 10 years starting at age 50. Colonoscopy visualizes the entire colon, allowing immediate removal of precancerous polyps if found.

Other screening options include flexible sigmoidoscopy (endoscopic exam of the last 60 cm of colon) every five years or double contrast barium enema every 5 years. CT colonography (virtual colonoscopy) may be an option in the future. Screening tests using fecal material exist; they are less invasive, but will not detect early lesions. Fecal tests are only effective in detecting cancer or more advanced polyps. They require annual performance for optimal effect.

The disadvantages of these screening options are the increased frequency of testing and the need for further intervention in the event of a positive result. If a patient is not willing to have repeated testing or not willing to undergo colonoscopy or surgery for a positive screening test, these options will not be effective.

Certain individuals are at higher than average risk for colon cancer and should have more frequent and possibly earlier screening. These individuals will have one or more of the following and should discuss screening needs with their physician:

— Personal history of colorectal cancer or adenomatous polyps;
— Personal history of chronic inflammatory bowel disease (Crohn’s disease or ulcerative colitis);
— Strong family history of colorectal cancer or polyps (cancer or polyps in a first-degree relative, such as parent, sibling, or child, younger than 60 or in two or more first-degree relatives of any age);
— Known family history of hereditary colorectal cancer syndromes such as familial adenomatous polyposis (FAP) or hereditary non-polyposis colon cancer.

PNR: What treatments are available?

Dr. Huck: The keystone to treatment of colorectal cancer is surgical resection. If there is spread of disease beyond the wall of the colon, chemotherapy may increase cure rate if cancer is caught early and may increase survival even if cancer is already metastatic.

PNR: What is the prognosis for early discovery of colorectal cancer?

Dr. Huck: If the disease is confined to the bowel, five-year survival is 90 percent, but five-year survival is only 68 percent if disease has extended locally outside the bowel, and only 10 percent if distant metastases are present.

PNR: Any final thoughts?

Dr. Huck: The best way to deal with colorectal cancer is to prevent it from occurring. Regular age- and risk-appropriate screening will significantly decrease the incidence of colorectal cancer. Removal of polyps eliminates potential cancer before it begins — without surgery, without chemotherapy. Waiting for symptoms to develop is waiting too long and may be too late to save a life.