The most common first sign of anal cancer is bleeding from the anus or blood on the stool. Other early signs include a lump near the anal opening, persistent itching, pain or pressure in the anal area, and changes in bowel habits like narrower stools. Some people have no symptoms at all in the earliest stages, which is why the disease is sometimes found during a routine exam.
Bleeding and Pain
Rectal bleeding is the symptom that brings most people to a doctor. You might notice bright red blood on toilet paper, in the bowl, or mixed into your stool. It can be intermittent at first, easy to dismiss as a one-time thing. But bleeding that keeps coming back, even if it’s small amounts, is worth getting checked.
Pain or a feeling of constant pressure in the anal area is another early signal. Some people describe it as feeling like they always need to have a bowel movement, even right after going to the bathroom. This fullness or urgency happens because a growth inside the anal canal takes up space and irritates the surrounding tissue.
Lumps and Skin Changes
A lump or mass at or just inside the anal opening is sometimes the first thing a person notices. As it grows, the lump may bleed, itch, or become painful. Persistent itching around the anus, without an obvious cause like a skin condition or hygiene issue, can also be an early sign. These symptoms overlap heavily with hemorrhoids, which is one reason anal cancer often gets misidentified at first.
Changes in Bowel Habits
A tumor growing in the anal canal can physically narrow the passageway, producing thinner or ribbon-like stools. You may also develop new constipation or notice that your stool looks different than it used to. Any sustained shift in your normal pattern, lasting more than a few weeks, deserves attention.
Why These Symptoms Get Mistaken for Hemorrhoids
Hemorrhoids and anal cancer share three hallmark symptoms: bleeding, pain, and lumps. That overlap leads many people to assume their symptoms are benign and delay getting examined. MD Anderson Cancer Center puts it plainly: don’t assume you have hemorrhoids when something abnormal is happening. Seeing blood once probably doesn’t mean cancer, but it should prompt you to get checked so you know for certain what’s causing it.
A key difference is persistence. Hemorrhoids tend to flare and improve, especially with dietary changes or over-the-counter treatments. Anal cancer symptoms typically don’t resolve on their own and gradually worsen over weeks or months. A lump from anal cancer may feel harder and more fixed in place than a soft, compressible hemorrhoid, though only an exam can distinguish the two reliably.
How Anal Cancer Is Found
The initial step is usually a digital rectal exam, where a doctor feels for unusual lumps or growths with a gloved finger. If something abnormal is felt, the next step is an anoscopy: a short, lighted tube about three to four inches long is gently inserted to give the doctor a direct view of the anal lining. If a suspicious area is found, a small tissue sample is taken and sent to a lab. When the growth is very small, the doctor may remove it entirely during this biopsy.
For people at higher risk, screening can catch the disease before symptoms ever appear. Current guidelines recommend anal screening (similar to a cervical Pap smear) for several groups: men who have sex with men and transgender women with HIV starting at age 35, and other people living with HIV starting at age 45. People with a history of certain HPV-related conditions, organ transplant recipients, and those on long-term immune-suppressing medications may also benefit from screening, typically through shared decision-making with their provider.
Who Is Most at Risk
About 91% of anal cancers are caused by HPV (human papillomavirus), making it the dominant risk factor. Around 8,348 people are diagnosed with anal cancer in the United States each year, and roughly 7,600 of those cases are HPV-related.
Other factors that raise risk include:
- HIV or AIDS, which weakens the immune system’s ability to clear HPV infections
- A history of HPV-related precancers or cancers of the cervix, vulva, vagina, penis, or throat
- Immunosuppression from organ transplant medications or autoimmune conditions
- Having more than 10 sexual partners
- Chronic anal inflammation, including frequent redness, swelling, or soreness
HPV vaccination significantly reduces the risk of developing the types of HPV most closely linked to anal cancer. Vaccination is most effective when given before exposure to the virus, which is why it’s routinely recommended in adolescence, though it’s approved for adults up to age 45.
Why Early Detection Matters
When anal cancer is caught while still localized, meaning it hasn’t spread beyond the anal area, the five-year survival rate is 85%. Once it has spread to distant parts of the body, that number drops to about 36.5%. The gap between those two numbers is the practical argument for not ignoring persistent symptoms. Early-stage anal cancer is highly treatable, and the difference between early and late detection can be dramatic.