Despite being close in proximity on the human body, anal and rectal cancer are very different types of cancer. They also have very different treatment strategies. In both types of cancer it is important to diagnose and treat the cancer early.

Dr. Stephanie Carr, colorectal surgeon at Marshfield Medical Center, provides more specifics as to the differences.

Anal cancer

Anal cancer occurs at the anus and is more easily detected during an office exam. It is rare, accounting for only 4% of all gastrointestinal tract cancers. It is most commonly seen in patients in their 60’s. It’s also more common in women.

Risk factors for anal cancer include human papillomavirus, or HPV, immunosuppression, history of anal warts and anal intercourse.

“Symptoms of anal cancer are often quite vague,” Dr. Carr said. “They can include anal pain, a mass, bleeding or incontinence.”

The treatment for most anal cancers is chemoradiation. If the tumor does not respond, surgery to remove the anus may be necessary which results in a permanent colostomy.

Rectal cancer

Rectal cancer occurs within the rectum, the last portion of the gastrointestinal tract. It is detected and diagnosed with endoscopy, such as a colonoscopy. It is more common than anal cancer, as both men and women have about a 4% risk of developing colon or rectal cancer in their lifetime.

“There are known genetic predispositions that increase the risk of rectal cancer,” Dr. Carr said. “Other risk factors include inflammatory bowel disease, poor diet, obesity, alcohol and tobacco use.”

Symptoms include rectal bleeding, pain, a change in bowel habits and unexplained weight loss.

The treatment varies depending on the staging of the disease. Small tumors may be removed with a simple surgical procedure. More advanced tumors may require chemotherapy and radiation followed by surgical removal of the rectum.

Colonoscopy screening

Colorectal cancer often begins as a polyp, which can be visualized and removed during a colonoscopy. The procedure can prevent the development of most colorectal cancers.

“Colonoscopies are the best way to prevent colon and rectal cancer by removing pre-cancerous polyps,” said Dr. Carr. “Colonoscopies are now recommended at the age of 45, but patients with a family history of colorectal cancer will need a colonoscopy even earlier.”

Call your primary provider to set up an appointment for a colonoscopy screening.