Don’t confuse these types of cancer
Key takeaways:
- Rectal cancer occurs in the last part of the colon, while the anus is where stool comes out.
- Anal cancer has a lower prevalence than rectal cancer, and diagnosis usually is when someone thinks they have a hemorrhoid.
- Talk to your health care provider about when you should start getting a colonoscopy screening.
Anal and rectal cancer occur in parts of the body near each other, and they both have prevention steps and time-tested treatments. But they are different types of cancer, says Raman Kumar, MD, a colorectal and general surgeon with OSF HealthCare.
Rectal cancer
Dr. Kumar says the rectum is the last part of the colon, where stool is stored.
Signs of rectal cancer include bleeding, irregular bowel movements (such as the shape of the stool changing and the inability to have a complete bowel movement), weight loss, fatigue and pain in the rectal area.
Rectal cancer impacts men and women roughly equally, and it’s seen “at almost any age,” Dr. Kumar says. If you smoke and eat a lot of red meat and processed food, your risk will go up.
Anal cancer
Dr. Kumar says the anus is where stool comes out. He says signs of anal cancer can be like those of rectal cancer. But often, he says an anal cancer diagnosis starts when a person believes they have hemorrhoids, or when the veins or blood vessels around the anus and lower rectum become swollen and irritated due to extra pressure.
“It turns out not to be a hemorrhoid. It could be a mass or a lesion. You could have some bleeding, especially when you’re wiping with toilet paper or wet wipes,” Dr. Kumar says.
Anal cancer’s prevalence in the United States is “very low,” Dr. Kumar says, with around 8,000 cases per year. Around two-thirds of the cases are women, and it’s more common in age 50 and up.
“The number one cause of anal cancer is HPV, the human papillomavirus,” Dr. Kumar says. “So, it is considered a sexually transmitted disease.”
But he says you don’t have to be sexually active to get anal cancer. Regardless, there are vaccines for the most common HPVs that cause cancer.
Prevention and treatment
Symptoms aside, Dr. Kumar says there’s a must-do for anal and rectal cancer prevention: get on a colonoscopy schedule as advised by your health care provider. A colonoscopy is when a provider inspects your colon and surrounding areas using a tiny camera on the end of a tube. Dr. Kumar says generally, colonoscopies start at age 45. But they could start earlier if you have a family history of cancer.
Other tips: Don’t smoke. Exercise regularly. Eat a healthy diet with plenty of fruits, vegetables and fiber. Thirty grams of fiber per day is a good goal, Dr. Kumar says.
If you do have symptoms of anal or rectal cancer, see a provider to get checked out.
Dr. Kumar says treatment for anal cancer is usually chemotherapy and radiation therapy. He says when treated properly, the typical five-year survival rate is around 80%.
“The only times we would operate on anal cancer are to get the original [cancerous] mass out and if the cancer comes back,” Dr. Kumar explains.
For rectal cancer, Dr. Kumar says around 40% of people can also be treated with chemotherapy and radiation. Others will need surgery to remove the cancer. But Dr. Kumar says medicine has progressed to where people can typically avoid a colostomy, or when a part of the colon is diverted outside the skin to bypass a damaged part of the colon. This is temporary and comes with a bag that collects the waste that would normally leave your body via a bowel movement.
Learn more
Read more about prevention and treatment of rectal and anal cancer on the OSF HealthCare website.