Could You Have Anal Cancer? 10 Symptoms to Watch Out For

Anal cancer is distinct from colorectal cancer: while they can share some symptoms, they arise in different parts of the large intestine. Anal cancer is relatively uncommon and is diagnosed more often in women. About one-quarter of cases produce no symptoms, and when symptoms do occur they vary; in some patients signs do not appear until the disease is more advanced.

1. Risk Factors for Anal Cancer

Before assessing symptoms, clinicians typically review risk factors for anal cancer. Infection with human papillomavirus (HPV) or a history of genital warts raises risk, although most people with HPV do not develop anal cancer. Risk also increases with age—especially after 50—and with tobacco use. Additional risk factors may be identified during evaluation.

2. The Most Common Symptom: Bleeding

Minor anal bleeding can be an early symptom of anal cancer and is reported in nearly half of affected patients. Hemorrhoids are a common, usually self-limited cause of rectal bleeding, but any bleeding that persists longer than two to three weeks or occurs with weight loss or fecal leakage should be evaluated by a healthcare provider. Persistent bleeding may also reflect other serious conditions, such as Crohn’s disease or ischemic colitis.

3. Persistent Rectal Itching

Anal itching (pruritus ani) is common and can result from a variety of benign causes, including hemorrhoids, excessive washing, inflammatory skin conditions (psoriasis, contact dermatitis), metabolic disorders (diabetes, thyroid disease), yeast overgrowth, and some sexually transmitted infections. Although most cases are not serious, persistent or severe itching — or the presence of anal leakage — should prompt medical evaluation, as it can, rarely, be a sign of anal cancer. Consult a healthcare professional for assessment and appropriate testing.

4. Changes in Bowel Movements

The color, consistency, and frequency of bowel movements offer important clues about digestive and overall health. Changes in these characteristics can reflect liver disease, bowel obstruction, or other conditions, including cancer. An increased frequency of bowel movements can be an early sign of anal cancer; persistent straining, narrowed stools, visible dark or red blood, fecal incontinence, ongoing bloating, or recurrent diarrhea should prompt timely medical evaluation.

5. Abnormal Discharge

Rectal discharge describes any nonfecal substance expelled from the rectum, often noticed on underwear or with stool. Patients may experience tenesmus — a strong urge to defecate but only pass small amounts of stool or mucus. Causes include irritable bowel syndrome, sexually transmitted infections, and other conditions, and, less commonly, it can indicate anal cancer. The discharge is typically mucoid or purulent and may be intermittent or continuous; medical evaluation is advised.

6. Anal Pain

Anal pain can result from common conditions such as hemorrhoids or an anal fissure, as well as from perianal abscesses, infections, or dermatologic disorders. Less commonly, it may signal anal malignancy; the presence of bleeding or changes in bowel habits heightens concern for a mass. Persistent, recurrent, or worsening symptoms should prompt evaluation by a healthcare professional.

7. Mass or Growth in the Anal Opening

A lump or swelling in the anal region should be evaluated by a clinician, as it can reflect benign conditions—such as rectal polyps, which infrequently become cancerous—or, less commonly, malignancy. Anal cancer develops when normal cells undergo abnormal transformation and form a tumor near the anus. Metastasis is uncommon; when it occurs the liver, bones and lungs are the most frequent sites.

8. Swollen Lymph Glands

Lymph nodes are small immune organs that contain lymphocytes and other immune cells; they commonly enlarge in response to infection, inflammation, or other immune challenges. Enlargement of the inguinal (groin) nodes can result from local or systemic infections and, less commonly, from malignancies such as anal or other cancers. Nodes that are hard, non-tender, fixed, or progressively enlarging warrant medical evaluation, as these features can be concerning for cancer.

9. Pressure Around the Anus

Persistent or worsening rectal pressure warrants prompt medical evaluation. Patients may experience a continual sensation of incomplete evacuation (tenesmus) even after defecation; this can be caused by a rectal mass. Larger tumors may produce partial or complete rectal obstruction, resulting in progressive constipation and cramping.

10. Anemia

Rectal cancer can cause bleeding that lowers red blood cell levels. Patients who report fatigue will typically have a complete blood count (CBC) to evaluate white blood cells, red blood cells, and platelets. Anemia—insufficient healthy red blood cells to deliver adequate oxygen to tissues—can produce symptoms such as weakness, chest pain or shortness of breath, and lightheadedness or dizziness.