8 Early Warning Signs of Anal Cancer—and When to See a Doctor

Anal cancer is uncommon, but catching it early makes treatment more effective and less invasive. If you’ve noticed possible anal cancer symptoms or unexplained rectal bleeding, it’s worth understanding what’s normal—and what isn’t. Many of these signs overlap with benign problems like hemorrhoids, so the key is persistence, change, or a combination of symptoms. Here are eight clues to know, plus when to seek care in the USA.

The eight red flags to watch for

  1. Rectal bleeding (bright red on toilet paper or in the bowl).
  2. Persistent anal pain or a pressure/fullness sensation.
  3. A new anal lump or growth near the opening.
  4. Change in bowel habits—newly thinner (“pencil”) stools or ongoing constipation/diarrhea.
  5. Anal itching that doesn’t improve.
  6. Unusual anal discharge or mucus.
  7. Leaking stool or new difficulty controlling bowel movements.
  8. Swollen, tender nodes in the groin.

These are among the most common ways anal carcinoma first shows up clinically. While hemorrhoids and fissures often cause bleeding or pain, symptoms that persist, worsen, or combine (for example, bleeding plus a new lump) should prompt a medical evaluation. A clinician can examine the area, and if needed, perform anoscopy and biopsy to confirm the cause.

Why these symptoms matter (and how common anal cancer is in the U.S.)

Anal cancer accounts for a small fraction of gastrointestinal cancers, but U.S. estimates still project thousands of new diagnoses each year. In 2024, the American Cancer Society estimated about 10,540 new cases and 2,190 deaths nationwide. Rates are slightly higher in women than men, and incidence overall remains far lower than colon or rectal cancer. Because early symptoms can be subtle—or mistaken for hemorrhoids—many people delay care. Recognizing the warning signs and acting quickly improves the odds of successful treatment and may reduce the need for surgery.

What raises risk—and what you can do about it

Long-term infection with human papillomavirus (HPV) is the strongest known risk factor for anal cancer. Additional factors include a history of cervical or vulvar precancer/cancer, immunosuppression (including HIV), smoking, and receptive anal intercourse. The HPV vaccine, recommended in the U.S. beginning in adolescence and available to many adults up to age 45, helps prevent HPV-related cancers. If you’re in a higher-risk group, ask your clinician about targeted screening (such as anal cytology or high-resolution anoscopy) and regular checkups. Avoid tobacco, practice safer sex, and keep vaccinations up to date to lower overall risk.

When to call a doctor—and what to expect at the visit

Seek prompt care for any rectal bleeding that lasts more than a day or two, returns repeatedly, or is accompanied by pain, a new lump, or unintended weight loss. Even if hemorrhoids seem likely, persistent bleeding deserves evaluation. During your visit, a clinician may perform a visual and digital rectal exam, order stool tests, or refer you for anoscopy; biopsy is the definitive way to diagnose or rule out cancer. Many U.S. patients can start with a primary-care provider, gynecologist, colorectal surgeon, or a same-day/urgent care clinic; telehealth can also triage symptoms and expedite in-person care if needed. If cancer is found, most modern treatment plans combine chemotherapy and radiation, with surgery reserved for specific situations.

Bottom line

Don’t ignore changes around the anus or rectum—especially bleeding, a new mass, or lasting pain. Most causes aren’t life-threatening, but early evaluation is the safest move. If any of the eight warning signs above sound familiar, book an appointment with a qualified U.S. clinician to discuss next steps and whether you might benefit from vaccination, screening, or specialty referral. Acting early protects your health and gives you more options.