Anal Cancer

21.03.2024

ANAL CANCER DIAGNOSIS AND TREATMENT

Anal cancer is a type of cancer that starts in the anus area. This type of cancer usually occurs on the inner lining of the anus or the last part of the rectum. Causes of anal cancer may include factors such as human papillomavirus (HPV) infection, anal intercourse, anal hygiene habits, smoking, immune system weakness, and family history. Anal cancer can be treated successfully when diagnosed in the early stages. However, when neglected or diagnosed at an advanced stage, treatment can be more challenging. Early diagnosis can prevent the spread of the disease and the emergence of complications. Therefore, regular medical check-ups and taking preventive measures such as HPV vaccination play an important role in reducing the risk of anal cancer. Anal cancer can be prevented or controlled with early diagnosis and treatment. This type of cancer can cause serious complications and a significant decrease in quality of life if left untreated. Therefore, understanding risk factors, following regular health check-ups, and taking care of your health are critical in reducing the likelihood of a serious disease such as anal cancer.

WHAT ARE THE RISK FACTORS?

Anal cancer risk factors can be affected by a variety of factors that can increase a person's likelihood of developing this type of cancer.

HPV Infection: Human papillomavirus (HPV) is the most important factor that can increase the risk of anal cancer. HPV infection can be transmitted, especially through anal sex, and chronic infections can increase the risk of anal cancer.

Sexual Behaviors: Individuals who have multiple sexual partners or practice anal sex may have a higher risk of anal cancer.

To smoke: Smoking may increase the risk of anal cancer. The chemicals in cigarette smoke can damage the anus and rectal area.

Immune System Problems: People with weakened immune systems may have a harder time controlling HPV infections, which may increase the risk of anal cancer. Diseases that affect the immune system, such as HIV, may increase the risk.

Anal Condylomas: Condylomas (genital warts) in the anal area may increase the risk of anal cancer. Condylomas are often associated with HPV infection.

Age: Anal cancer is generally more common in individuals over the age of 60.

Genetic Factors: Family history may increase the risk of anal cancer in some families.

Anal Fistulas and Fissures: Chronic anal fistulas or fissures may increase the risk of anal cancer.

Anal Hygiene: Poor anal hygiene practices may increase the risk of anal cancer.

Alcohol and Drug Use: Excessive alcohol consumption and drug use may increase the risk of anal cancer.

Anal cancer risk factors may vary from person to person, and a person's combination of multiple risk factors may increase their risk of cancer. Being aware of risk factors, getting regular medical check-ups, and making healthy lifestyle choices can help reduce the risk of anal cancer.

Image 1: Anal cancer is a type of cancer that starts in the anus (digestive system exit area).

HOW DOES IT OCCUR?

The mechanisms of anal cancer development are complex and are mostly associated with HPV (Human Papillomavirus) infection. HPV causes cellular changes in the anus and genital area, paving the way for cancer development. Lesions caused by HPV lead to cellular abnormalities and can develop into precancerous lesions. Over time, these lesions can turn into cancer cells and cancer may develop. In addition, smoking, immune system problems, chronic anal injuries and other risk factors may also be effective in the development of anal cancer. However, HPV infection constitutes the basic development mechanism of anal cancer, and therefore preventive measures against HPV are important in reducing the risk of anal cancer.

WHAT ARE THE SYMPTOMS?

Symptoms of anal cancer may vary from person to person and may change over time in the same person. These symptoms occur because the cancer typically occurs in the last part of the rectum or the anus area. Symptoms of anal cancer may include:

Anal Bleeding: One of the most common symptoms of anal cancer is anal bleeding. Blood may be noticed on toilet paper or in stool. This bleeding is usually painless, but may be continuous.

Pain or Discomfort: Pain or discomfort in the anal or rectal area may be one of the symptoms of anal cancer. This pain can often increase when sitting for long periods of time or during bowel movements.

Stool Changes: Anal cancer can sometimes cause changes in stool. Constipation, diarrhea, or changes in the shape and color of the stool may be observed.

Anal Itching or Burning: Itching or burning sensation in the anal or rectal area may be among the symptoms of anal cancer.

Anal Discharge: There may be a foul-smelling or bloody discharge.

Narrowing of the Anus: Anal cancer can sometimes cause the anus to narrow, which can lead to difficulty defecating.

Swelling of Lymph Nodes: Anal cancer can cause swelling of the surrounding lymph nodes.

Fever and Malaise: In advanced anal cancer cases, symptoms such as fever and fatigue may occur as the body's defense mechanism.

Early diagnosis and treatment is important in the treatment of anal cancer, so be alert to any suspicious symptoms.

HOW IS IT DIAGNOSED?

Anal cancer is diagnosed using various medical tests and imaging methods. First, the patient's symptoms and medical history are taken into consideration. The doctor may check the anus and surrounding tissues by performing a rectal examination. However, more precise information is needed to make a diagnosis. Therefore, endoscopic methods such as sigmoidoscopy or colonoscopy are used. During these procedures, a camera is placed in a thin tube and the inner surface of the anus and rectum is observed. Additionally, samples of abnormal tissue are taken through a process called biopsy and these samples are sent for laboratory tests. Confirming the diagnosis of anal cancer is based on these biopsy results. Imaging tests (for example, computed tomography or magnetic resonance imaging) may also be used to evaluate the spread of cancer. Once the diagnosis is made, treatment begins and an appropriate treatment plan is created to control the spread of the disease.

Image 2: There are many reasons for the development of anal cancer, such as HPV virus, smoking and immune system weakness.

WHAT ARE THE PATHOLOGICAL TYPES?

Anal cancer can be divided into different pathological types according to their histopathological features. The two most common pathological types of anal cancer are:

Squamous Cell Carcinoma: Most anal cancers arise from a type called squamous cell carcinoma. This type of cancer arises from squamous cells lining the outer surface of the anus. Squamous cell carcinoma, like other squamous cell carcinomas, can be aggressive to varying degrees.

Adenocarcinoma: This type of anal cancer arises from the glandular cells lining the inner surface of the anus. It may derive from glands located inside the anal canal. Adenocarcinoma is less common than squamous cell carcinoma.

These are the most common pathological types of anal cancer, although rarer subtypes and mixed types of cancer may also exist. Determination of pathological types can affect treatment options and prognosis, so an accurate diagnosis and pathological examination is important.

HOW IS TUMOR STAGING DONE?

Anal cancer staging is a method used to determine the size of the cancer, its extent, and its spread to the lymph nodes. This staging process helps determine cancer treatment options and prognosis. Anal cancer staging is done through the following steps:

Stage 0 (Carcinoma in situ): This stage is the stage where the cancer is limited to the superficial layer. The tumor is located in the uppermost layer of the mucosa and has not spread to surrounding tissues.

Stage I: At this stage, the tumor is confined to the inner surface of the anal canal and has not spread to nearby lymph nodes.

Stage II: The tumor has spread to the deeper layers of the anal canal or perianal skin, but usually not to the lymph nodes.

Stage III: At this stage, the tumor has spread to surrounding tissues or lymph nodes. Spread to lymph nodes may further subdivide stage III.

Stage IV:The cancer has spread beyond the anal canal or to distant organs (for example, the liver or lungs). This stage represents the advanced stage of cancer.

Staging is done based on physical examination, endoscopic examination, imaging tests such as computed tomography (CT) or magnetic resonance imaging (MRI), and biopsy results. Staging results help determine the patient's treatment plan. While early-stage anal cancers are usually treated with surgery or radiotherapy, treatment options such as chemotherapy and immunotherapy are more commonly used in advanced-stage cancers.

HOW IS TREATMENT DONE ACCORDING TO STAGES?

Treatment of anal cancer may vary depending on the stage of the cancer, the size of the tumor, and the patient's general health condition. It is usually treated using a combination of surgery, radiotherapy and chemotherapy.

Treatment approaches for anal cancer according to stages:

Stage 0 (Carcinoma in situ): At this stage, the cancer is limited to the superficial layer. Treatment can usually be done by local excision (surgical removal) or ablation (destroying the superficial tumor).

Stage I:

Local excision: Small tumors can be removed surgically.

Radiotherapy: Cancer cells can be killed using high-energy rays.

Stage II:

Combined treatment: Surgical removal and radiotherapy can be used together.

Radiotherapy and chemotherapy: This combination can reduce the size of the tumor and reduce the risk of recurrence after surgery.

Stage III:

Radiotherapy and chemotherapy: This treatment can control the spread of cancer and can be used before or after surgery.

Stage IV:

Systemic chemotherapy: May be used to control the spread of cancer and relieve symptoms.

Targeted drugs and immunotherapy: Specific drugs can target cancer cells, and immunotherapy can stimulate the immune system to fight cancer.

The treatment plan is determined depending on the patient's age, general health condition and medical history. The treatment approach may be different for each patient. Your treatment team will determine the most appropriate treatment options specifically for you. Supportive care and follow-up are also important during treatment, so you should communicate with your physician regularly throughout your treatment process.

Image 3: In anal cancer, complaints such as blood in the stool, mass and pain in the anus area may be observed.

WHAT ARE THE DRUGS USED IN TREATMENT?

Chemotherapy, hormonal drugs, smart drug treatments and immunotherapies used in the treatment of anal cancer may include:

Chemotherapy drugs:

5-Fluorouracil (5-FU): It is a chemotherapy drug frequently used in the treatment of anal cancer. It works by stopping the growth of cancer cells.

Mitomycin C: This drug is also used to prevent the growth of cancer cells. It is usually used in combination with radiotherapy.

Smart Drug Therapies:

Smart drug treatments target specific genetic or molecular characteristics of cancer cells. Although there are no smart drugs specifically designed for anal cancer, research and development are ongoing.

Immunotherapies:

Pembrolizumab: Used as an immunotherapy treatment, this drug stimulates the immune system to fight cancer cells. It can be used in some cases in the treatment of anal cancer.

Nivolumab: Another immunotherapy drug, Nivolumab can be used to activate the immune system against cancer.

These medications are included in the treatment plan depending on the patient's medical history, the stage of the cancer, and other factors. Physicians directing the treatment determine the most appropriate drug combination and follow the treatment process. The treatment plan may be different for each patient, so it is important to follow your doctor's recommendations.

HOW SHOULD FOLLOW-UP BE CARRIED OUT AFTER RECOVERY?

Follow-up after recovery from anal cancer is important to monitor the patient's health and evaluate the results of treatment. Follow-up may include regular examination, imaging tests, and blood tests to evaluate the patient's response to treatment and detect possible relapses early. More frequent monitoring is generally recommended for the first two years after treatment, after which it may be tapered periodically. Follow-up duration and frequency may vary depending on the patient's age, treatment results and stage of the disease. During follow-up, the doctor reviews the patient's overall health, evaluates symptoms, and provides additional treatment or support if necessary. A good follow-up program can help patients live a healthy life and increase the chance of detecting possible complications early. Therefore, it is important to follow post-treatment follow-up recommendations.