Anal Cancer
Anal cancer is considered a rare cancer, but the number of patients receiving a diagnosis has been growing over the last four decades.
Anal cancers make up 0.3% of global cancer cases, with around 54,000 new cases diagnosed per year worldwide.
Around 85% of anal cancers are squamous cell anal carcinomas (SCAC), and most of these cancers are due to the HPV virus. Being vaccinated against HPV lowers the risk of anal cancer. Anal cancers that are caught in the earliest stages have an 85% 5-year survival rate.
What is anal cancer?
The anus is found at the very end of the large intestine. It’s connected to the rectum through a sphincter. The anus is the last part of the digestive system that poop goes through before it exits the body.
Cancer in the anus forms in the tissues of the anus. This can appear in the lining (mucosa) or in the skin outside of the anus that contains hair follicles and sweat glands.
While it’s easy to get them confused, anal cancer is not the same thing as rectal cancer; these are two different parts of the body and the tumors that form in each of these areas need unique treatment plans.
Types of anal cancer
The type of anal cancer you have will depend on where it started.
Squamous Cell Anal Carcinoma
The most common type, 85%, of anal cancer is squamous cell anal carcinoma, or SCAC. This cancer begins in flat cells lining the anal canal. Anal cancer treatment guidelines are designed to treat this type of cancer.
Rare types of anal cancer
A few other rare types of anal cancer include adenocarcinomas, basal cell carcinomas, melanoma, gastrointestinal stromal tumor (GIST), and anal lymphoma.
Staging anal cancer
If you have anal cancer, you need to know your stage. This helps you understand the size of your tumor, where the cancer is now, and the best treatment plan for your unique situation.
Anal cancer is staged on a scale from 0-IV (0-4) using the TNM staging system.
What causes anal cancer?
Risk factors put you at a higher risk of getting cancer. Some risk factors can be controlled with lifestyle changes, and others cannot.
These are scenarios researchers have found that can increase your risk of getting anal cancer.
- HPV infection
- Weakened immune system (due to HIV, organ transplant, medications, etc.)
- Smoking
- Other cancers in the genitals
Just because you have a risk factor, that doesn’t mean you will get anal cancer.
Can you prevent anal cancer?
The following steps can help reduce your risk of anal cancer:
- Get vaccinated for HPV
- Get screened for anal cancer
- Treat any HSIL found
- Stop smoking
There are not any current recommendations for routine anal cancer screening for the general population.
As with every cancer, there are steps you can take to adopt a healthy lifestyle and reduce your overall cancer risk, such as maintaining a healthy weight, not smoking, and limiting or eliminating alcohol.
Learn more about cancer prevention from the American Institute for Cancer Research.
What are some anal cancer statistics?
Based on GLOBOCAN 2022 data:
- An estimated 54,300 people were diagnosed with anal cancer globally, and 22,000 died from the disease.
- Anal cancer affects women more frequently than men.
- Rising incidence and mortality have been reported over the past four decades across the Americas, Northern and Western Europe, and Australia.
- The disease is more common in older adults.
- The median age at diagnosis is 60s or 70s.
- The incidence of anal cancer has been increasing by around 2% per year.
- While incidence is currently highest in high-income countries, it is expected to increase in low-income countries in the future due to higher HPV prevalence and lower HPV vaccine coverage.
What are my odds of surviving it?
Anal cancer is highly treatable if caught early. Doctors use what’s called “survival statistics” to understand the likelihood of a patient beating the disease.
According to the National Cancer Institute, 70.3% of patients are alive five years after an anal cancer diagnosis (in the U.S.).
Survival Statistics
Detailed survival statistics are based off where the cancer is located and if it has spread:
Localized
The cancer hasn’t spread
- 39.5% of cases
- 83.3% of patients are alive five years after diagnosis
Regional
The cancer spread to nearby lymph nodes
- 37% of cases
- 676.3% of patients are alive five years after diagnosis
Distant
The cancer has spread to lymph nodes and/or organs
- 14% of cases
- 36% of patients are alive five years after diagnosis
What types of tests should I expect to undergo?
Doctors typically use these tests to diagnose anal cancer:
- Physical exam with a digital rectal exam (DRE)
- Anoscopy
- Biopsy
- Proctoscopy
- Endo-anal or endorectal ultrasound
Once you’ve been diagnosed, you can expect these tests:
- CT scan
- Chest x-ray
- MRI
- PET scan
- Pelvic exam
I’m facing a diagnosis: What are my next steps?
If you’re facing a diagnosis, the GI Cancers Alliance is here for you. If you’re newly diagnosed, work with your doctor to create a treatment plan.
Explore therapies
Anal cancer treatment plans may include:
Chemotherapy
Radiation
Targeted therapy
Immunotherapy
Surgery may be an option for some patients.
Request testing
Ask your doctor about these additional tests—ideally before you begin treatment.
Biomarker testing
Genetic testing
