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Colorectal Cancer

More than 1 million people have survived colorectal cancer in the U.S. We’ve helped thousands do so, right here in Wisconsin and the Upper Peninsula.

Colon cancer is cancer that develops in the colon, the longest segment of the large intestine. Rectal cancer forms in the rectum, the last 6 inches of the large intestine leading to the anus. The term colorectal cancer refers to both colon and rectal cancer.

Over the past 20 years, survival rates for colorectal cancer have steadily increased. Green Bay Oncology is at the forefront of new research and technology to help with more effective forms of radiation and chemotherapy that have contributed to that increase. In fact, we have successfully treated more cases than any other provider in the region.

In addition to having more cancer-fighting doctors, Green Bay Oncology is one of only two participants in the National Cancer Institute’s Community Oncology Research Program. That means we’re able to conduct national-level clinical trials for colorectal cancer right here in our communities. To find out more about clinical trials and all of our colorectal cancer treatment options, schedule an appointment with one of our experts.

Colorectal cancer diagnosis

Most people with early colorectal cancer don’t have symptoms of the disease. Complicating the matter is that symptoms are often caused by conditions other than colorectal cancer, including hemorrhoids or inflammatory bowel disease. That’s why we recommend screening tests, such as a colonoscopy, for those 50 and over, and at a younger age for those at higher risk.

Reliable and accurate information is critical as you navigate this disease. We’re here to answer any questions you may have and to listen to your concerns. We welcome you to schedule a consultation with one of our colorectal cancer experts. We also recommend several reputable sources on the Internet, including the American Cancer Society, National Cancer Institute, and American Society of Clinical Oncology.

Why does colorectal cancer occur?

Most cases are random, but people at increased risk include those with precancerous polyps, a genetic predisposition, a strong family history, or those who suffer from Crohn’s disease or ulcerative colitis. Other risk factors include obesity, smoking and excessive alcohol consumption. Some research suggests that eating grilled red meat may also increase the risk.

How is colorectal cancer treated?

Treatment depends on several factors, including the stage of the cancer, your overall health and your preferences for treatment. We will listen to you, offer suggestions, and work with you to determine the best course of treatment and the one with which you are most comfortable. Methods of colorectal cancer treatment include surgery, chemotherapy and radiation.


Surgery is performed to remove cancer cells. Modern surgery can preserve normal, or near-normal, bowel function for most patients. This means that a colostomy, surgery that brings one end of the large intestine out through the abdominal wall to drain feces, is no longer the norm. When a colostomy is required, it is usually temporary.


Chemotherapy eradicates cancer cells through the use of anti-cancer medication. Colon cancer chemotherapy treatments usually continue for a six-month period. Side effects vary from person to person, but fortunately the side effects are moderate for most patients. We will fully explain what you are likely to experience and discuss current medications and other methods available to best alleviate as much discomfort as possible.


Used to treat most rectal cancer, radiation is a form of light therapy that destroys cancerous tissue. Treatment usually lasts for one to two months. Side effects may include diarrhea and rectal irritation.

Clinical Trials:

New treatment options are continually being developed. As the region’s only participant in the National Cancer Institute’s Community Clinical Oncology Program, we conduct national-level clinical trials right here in our communities and help to identify new ways to detect, diagnose, and treat cancer.

Types of treatment by stage of colorectal cancer

Staging indicates the severity of a person’s cancer and is integral in determining the appropriate treatment.

stage 1

Stage 1 colorectal cancer is confined to inside the bowel and hasn’t spread to the bowel wall. Standard treatment for Stage 1 colorectal cancer involves surgery to remove the cancer and a small amount of the tissue around the tumor. Additional treatments are usually not needed.

stage 2

Colorectal: Stage 2 colorectal cancer has invaded the bowel wall but has not spread outside the colon or into nearby lymph nodes.

Rectal: Stage 2 rectal cancers are usually treated with chemotherapy and radiation before surgery, followed by removal of the remaining cancer cells through surgery.

Colon: In stage 2 colon cancer, surgery to remove the cancer cells is usually the only procedure required, although chemotherapy may be needed in high-risk patients.

stage 3

Colorectal: Stage 3 involves the bowel and nearby lymph nodes but has not yet spread to other parts of the body. Treatment may be largely the same as that for stage 2 colon or rectal cancers: Tumors that are small enough and have not grown into nearby tissues may be removed by surgery, followed by radiation therapy. However, there are some differences in stage 3 colon and rectal treatments.

Rectal: Stage 3 rectal cancer is treated with chemotherapy and radiation prior to surgery, followed by removal of the remaining cancer cells through surgical procedures.

Colon: Surgery and chemotherapy are used to treat stage 3 colon cancer.

stage 4

Stage 4 colorectal cancer has spread to other organs, including the liver, lungs, peritoneum or ovaries. Treatment options for Stage 4 depend to some extent on how extensively the cancer has spread throughout the rest of the body. If the cancer cells have not spread beyond the liver, surgery is a viable treatment option. If the cancer has spread widely throughout the body, a combination of surgery, chemotherapy and radiation treatments are a common approach.


For more information on breast cancer and related treatment options, we recommend the following resources:

Dr. Michael Guiou with Dr. Alex Coffman and Dr. Mitch Winkler