Medically Reviewed By: Dr. Neeraj Goel, MBBS, MS, MCh (Surgical Gastroenterology)
Designation: Director of GI Surgery, GI Oncology, Dharamshila Narayana Super Specialty Hospital, Delhi
Review Date: August 18, 2026
The anal canal is short, measuring roughly 3 to 4 centimeters right at the end of the digestive tract. It is lined with sphincter muscles that open and close to give you control over bowel movements.
When cancer develops in the colon or rectum, surgeons usually remove that part of the bowel right away. Anal cancer is treated differently. Cutting out an anal tumor immediately would mean removing the sphincter muscles along with it, leaving you reliant on a permanent stoma bag on your abdomen.
Because most anal cancers are squamous cell tumors, they are sensitive to radiation combined with chemotherapy. That means we can often clear the tumor completely while keeping your natural bowel function intact.
You did nothing to cause this. It is caused by a mix of factors as follows:
People often delay getting checked because anal cancer symptoms mirror common problems like piles (hemorrhoids).
| Stage | What You Might Notice |
|---|---|
| Early Signs | Bright red blood on toilet paper or in the bowl; a firm, small bump near the opening; nagging itchiness that ointments do not relieve; mild aching when sitting or passing stool. |
| Later Warning Signs | Deep, persistent pelvic pain; mucous or watery discharge; feeling like you can never fully empty your bowels; hard, swollen lumps in the groin (enlarged lymph nodes); unexpected weight loss. |
Before deciding on treatment, we need to know the tumor's exact size, depth, and whether it touches nearby lymph nodes.
For most people with squamous cell anal cancer, chemoradiotherapy (CRT) is the standard curative treatment.
It involves radiation to the main tumor and local lymph nodes. At the same time, you receive mild chemotherapy drugs (typically 5-FU and Mitomycin-C) that make cancer cells more sensitive to the radiation.
Working together, they break down the tumor while keeping your sphincter muscles intact. You retain normal bowel control, and 80% to 90% of early-stage patients are cured without ever needing an operation.
Surgery is required in cases of residual disease.
Anal tumors take time to shrink. It can take up to 26 weeks after finishing radiation for a tumor to disappear completely. Regular check-ups help monitor your response:
In our practice, we frequently treat anal carcinoma. The majority of patients are cured with chemoradiation alone. Few require salvage surgery. We use minimally invasive techniques (laparoscopic and robotic) to perform abdominoperineal resections (APR). The majority of patients recover well after surgery and are discharged on day 3 or 4.
Both cause bright red blood on your tissue paper and local irritation. But piles are swollen blood vessels, while cancer is an abnormal tissue growth. If your symptoms last more than a week or two, have a doctor take a direct look with an anoscopy.
No. Most patients never need one. Because chemoradiotherapy cures the majority of cases without surgery, your muscles stay in place. Stomas are reserved as a backup if the tumor does not clear.
Abdominoperineal Resection is an operation that takes out the anal canal, rectum, and sphincter muscles. Because the muscle valve is removed, you will use a permanent stoma bag. It is used strictly for persistent or recurrent tumors.
High-risk HPV strains enter surface cells and turn off normal tumor defenses. Over several years, those altered cells can turn into cancer.
