The American Society of Clinical Oncology estimates that 8,300 cases of anal cancer will be diagnosed in 2019 and about 1,280 deaths will occur that year from anal cancer.
By contrast, some 140,250 people are predicted to be diagnosed with colorectal cancer in the U.S. in 2019, and about 51,000 people are predicted to die of the disease the same year.
Approximately half of all anal cancers are diagnosed before the malignancy has spread beyond the primary site, whereas 13% to 25% are diagnosed after the cancer has spread to the lymph nodes, and 10% are diagnosed after the cancer has spread to distant organs, or has metastasized.
When it is found early, anal cancer is highly treatable.
The overall five-year survival rate following diagnosis of anal cancer is 67%.
Who Gets Anal Cancer?
Most anal cancers (80%) are diagnosed in people who are over age 60. Prior to age 35, anal cancer is more common in men. However, after age 50, anal cancer is slightly more common in women.
The incidence rate of anal cancer is six times higher in single men as compared to married men.
Receptive anal intercourse is strongly related to the development of anal cancer.
Immunocompromised patients, such as those with HIV disease, are prone to get anal cancer. In this subgroup, the prognosis is worse than for non-immunocompromised patients.
What Are the Symptoms of Anal Cancer?
The most common symptom associated with anal cancer is bleeding.
Other signs and symptoms of anal cancer may include:
- Pain or pressure in the anal area
- Unusual discharges from the anus
- Lump near the anus
- Change in bowel habits
How Is Anal Cancer Diagnosed?
Anal cancer may be detected during a routine digital rectal exam or during a minor procedure, such as removal of what is believed to be a hemorrhoid.
The cancer may also be detected with more invasive procedures such as an anoscopy, proctoscopy, or endorectal ultrasound.
If cancer is suspected, a biopsy should be done and the specimen examined by a pathologist.
Staging workup may include an abdominal and pelvic CT scan, a pelvic MRI scan to assess the pelvic lymph nodes, a chest x-ray, and liver function studies. PET scans are sometimes performed.