Anus cancer

The anus has internal and external sphincters formed by muscle rings (closing muscles). The main function of this anatomical structure is the release of feces (defecation), and the sphincters control this process. Frequent pathologies of this zone are hemorrhoids, a mucosal defect, and tumors (malignant or benign) occur less often.

Despite the fact that malignant tumors occur quite rarely, they require timely and correct diagnosis and adequate therapy. Anal cancer is more common in 45-50 year olds. Women with neoplasia of the vulva or uterus are at risk of developing anal cancer, so this pathology is mostly associated with genital malignancies, and not with tumors of the gastrointestinal tract.

Classification

In histology, 4 forms of cancer of this area of ​​the body are distinguished:

• squamous, developing in the cells of the squamous epithelium that line the anal canal. This is the most common form, which occurs in 55% of cases and has a tendency to ulceration (is covered with ulcers);
• adenocarcinoma - it develops from the glandular epithelium in this area and accounts for 5-6%;
• basaloid cancer (24-30%) – develops at the point of transition of cylindrical epithelium into flat;
• melanoma, which originates from skin cells and has a dark color.

Such a large histological picture is associated with the diversity of the epithelium.

Causes of cancer

The causes of anal cancer are not completely known. But the factors that increase the probability of its appearance are precisely established:

• state of immunodeficiency - an example can be HIV infection and weakening after treatment with immunosuppressants;
• papillomavirus infection. First, condylomas appear in this area, which can provoke the appearance of cancer. Special importance is attached to highly oncogenic types of HPV (16 and 18);
• chronic diseases of this area, irritation and inflammatory process (polyps, fissure, fistula, hemorrhoids, proctitis);
• traumatization of the anus during anal contact, medical procedures and research;
• radiation load – treatment of cancer of other localizations (uterus, prostate, bladder) with rays, or contact with them by type of professional activity;
• inhalation of chemicals, including when smoking;
• age over 50 years, when the risk of tissue transformation appears.

Cancer of the anus: symptoms

In 19-20% of cases, the disease is not manifested at all. Often, the first complaint with tumors of this localization is discomfort and anal itching. Chronic itching develops gradually, but brings incredible discomfort to the patient's life. The skin around the anus can be dry or with elements of wet eczema, ulcers and increased skin folds. Itching is often the patient's only complaint.

Further, slight periodic pain in the anus begins during bowel movements and blood appears in the stool or bleeding from the anal canal. Over time, the severity of the pain increases, it becomes permanent (does not depend on bowel emptying) and unbearable in the late stage. The spread of pain to the genitals, perineum and lower abdomen is possible. Pain and itching are associated with a large number of nerve endings, swelling and muscle spasm.

Many people complain of a feeling of pressure in the passage and disturbance of stool (constipation). The patient is forced to strain during defecation. If the tumor grows into the vagina, a rectovaginal fistula is formed in women, through which fecal masses get inside. When it spreads to the urethra or prostate, urination disorders appear. In advanced cases, weakness and exhaustion are noted, and with the destruction of the sphincter tissues, fecal incontinence.

When the first suspicious symptoms are detected, which do not disappear for a long time and progress, a consultation with a proctologist-oncologist is necessary.

Diagnostics

External examination and finger examination make it possible to determine non-healing ulcers on the outside or formations inside the canal, as well as its dimensions. The doctor may find traces of blood on the glove after the examination. Enlarged lymph nodes are found in the groin area.

Anoscopy is a detailed examination of the anal canal with a special device. It gives a more complete picture of the location and size, a biopsy (tissue removal) is possible.

A biopsy of suspicious tissue followed by a histological examination allows this diagnosis to be removed in favor of a polyp and fissure, or confirmed with an accurate diagnosis of the type of cancer.

With a confirmed diagnosis, colonoscopy, MRI (or computer tomography) are used, which make it possible to determine the prevalence of the oncological process, that is, metastasis.

Women must undergo a gynecological examination for cervical neoplasms, given that these oncopathologies coexist.

Cancer of the anus: treatment

Therapy includes a large list of methods: radiation, chemotherapy and surgery. The choice is determined by the stage, location, size and occurrence of complications.

This issue is resolved after a consultation of an oncologist, a surgeon and a radiotherapist. The main principle of treatment is a combination: chemotherapy, which is prescribed for 5-6 weeks, radio and two cycles of chemotherapy.

Ionizing radiation is effective in squamous cell cancer, so the surgical method may not be used, and this makes it possible to preserve the function of the anal sphincters.

Radiotherapy can be remote and intratissue (radio-needles with 60Co are used). During the procedure, the region of the inguinal lymph nodes must be irradiated. At the same time, hyperthermia (local heating of the neoplasm with ultra-high frequency radiation) can be used.

Modern linear accelerators allow precise radiation treatment without damaging healthy tissues.

Chemotherapy doubles the effect of radiotherapy, as it affects neoplasms and metastases. The joint application of these two methods in the case of small formations is considered as an alternative to surgery.

Surgical intervention is recommended:

• at an early stage, when the size of the formation is up to 2 cm and external localization. In this case, its complete local deletion is possible;
• with cancer recurrence after radio- and chemotherapy;
• to alleviate the condition before applying combined chemoradiation therapy.

With local removal, a part of the anus with a neoplasm is operated on. After such an operation, there are no problems with intestinal function, since the sphincter is not affected.

Radical surgery (abdominal-perineal amputation) includes excision of the formation, rectum, adjacent tissues, sphincter and the area around it. At the same time, a permanent colostomy is formed - an artificially created opening on the abdominal wall for the discharge of feces. In the case of metastases, lymphadenectomy (removal of nodes) must be performed.

Prognosis and prevention

There is no specific prevention of the disease, but to reduce the risk, you need:

• proper nutrition, rich in fiber (bran, fruits, berries, vegetables, whole grains);
• exclusion from the use of fried foods, spicy foods, alcohol;
• regular bowel movements;
• hygiene of the anus (washing after defecation);
• avoidance of excessive stress;
• increasing motor activity, which is especially relevant for people with "sedentary" work;
• refusal to smoke;
• use of condoms, which helps reduce the risk of HPV infection and AIDS;
• reviews and examinations for risk groups (anoscopy and PAP test).

Cancer of the anus with early detection and timely treatment is not a sentence. With tumors less than 2-3 cm and the absence of metastases, chemoradiation treatment is effective for 80% of patients. Surgical operation helps achieve remission in 5 years in 57-70% of cases, and in metastases - in 20-21%. Patients who have undergone major surgery for recurrent disease are observed every 4-6 months with a mandatory examination of inguinal lymph nodes and an annual X-ray examination of the chest and abdomen.