High Resolution Anoscopy
Precancerous, or cancer-preventive, is a condition that can lead to the development of a malignant tumour. This means that there is no established cancerous lesion, but there is a process whereby abnormal cells have started to multiply, which may result in cancer.
Recognising the cancer-preventing condition as early as possible allows us to prevent cancer from developing.
In the case of the rectum, we can also talk about a cancer-preventing condition, which in most cases is linked to the human papillomavirus.
In this case, too, the condition can appear several years before the actual cancer develops.
Precancerous condition in the anus
Long-standing HPV infection of the same type can result in increased and uncontrolled cell division, which can lead to malignant tumours over a period of years.
This condition may be detected during rectal screening. Therefore, it is very important to attend regular screening tests, especially for groups at high risk (MSM population, HIV infected, immunocompromised, with a history of high risk gynaecological lesions) to minimise the need for intervention in case of a possible lesion. In the early precancerous stage, the doctor may decide to let the body work to fight the infection on its own, but topical or oral treatment may be considered, or surgery may be performed, which can cure the precancerous stage completely in a few minutes without affecting quality of life.
The results that are considered abnormal are
- ASCUS, ASC-H;
- LSIL, HSIL;
- AIN1, AIN2, AIN3.
AIN is short for Anal Intraepitelial Neoplasia, a medical term commonly used for abnormal cells growing on the surface of the rectum or skin around the rectum.
Neoplasia is therefore a lesion where a tissue grows without control.
A cancer-predisposing condition is the presence of AIN2 or AIN3, collectively known as HSIL.
Neoplasia is therefore a lesion where a tissue grows without control.
HPV-associated tumours around the anus are considered to be precancerous, i.e. cancer-preventing
- anal warts (condyloma acuminatum), which are caused by low-risk HPV (types 6 and 11) in the majority of cases and become malignant in 3-4% of cases;
- Bowenoid papulosis brownish-coloured warty growths usually in large numbers, may regress spontaneously – younger age group
- Bowen’s disease, which is essentially a skin disease that causes red, scaly patches to form on the skin; (usually associated with a high-risk HPV infection (HPV 16-18))
- verrucous (warty) carcinoma, which is a transition between anal wart and invasive squamous cell carcinoma.
It is caused by high-risk HPV infection;
It is not yet possible to say for sure whether AIN2 or AIN3 will develop into cancer, and if so, how long it will take.
Therefore, close follow-up is extremely important.
Also HPV-related, but associated with low-risk types (6, 11), is the development of giant condyloma (Buschke-Löwenstein tumour), which can be recognised by fused cauliflower-like lesions similar to warts.
Tumours around the anus
OVERVIEW Anal cancer is a relatively rare type of cancer that starts directly in the tissue surrounding the rectal orifice and should not be confused with colorectal cancer. The vast majority of anorectal cancers are caused by HPV infection.KNOWLEDGE Recognition of anorectal cancer is not easy, as it can easily be confused with other common lesions such as haemorrhoids or anal fissures.
As we test
A colposcope (gynaecological microscope) is a device similar to a pair of spectacles that emits light and can be used to magnify suspicious areas.
This special colposcope is called a high resolution anoscope (HRA
The procedure of the test
The specialist will first ask the patient about their sexual habits, of course. His or her previous medical history is very important, especially with regard to immunodeficiency and previous sexually transmitted diseases. This is followed by a finger prick examination, which is used to palpate the inner lining of the rectum. Anoscopic examination, which is performed by carefully inserting a light cable into the anus and examining the lower 6-8 cm of the mucosa with the eye. HPV is only found in the lower one and a half to 2 cm area where there is a non-scarring squamous epithelium, above this it does not survive. In a patient in a high risk group, the upper area is reviewed with a colposcope, or HRA. Since we scan at 10x-20x magnification, we obtain significantly more information than with the naked eye. The doctor cleans the surface of the mucous membrane with a stick of acetic acid, which helps to detect epithelial lesions, and can stain the area with iodine to distinguish between suspicious epithelial lesions (precancerous lesions) and intact epithelium. If necessary, a targeted sample is taken from the area under examination and sent for histological examination. The examination itself takes 10-30 minutes. There may be some minor discomfort but it is usually painless. No anaesthesia is needed during HRA, as the disease is initially asymptomatic or asymptomatic, but late detection significantly reduces the chances of cure and survival. With a healthy immune system, 80% of infections heal spontaneously within two years without causing abnormal cell changes. In a minority of cases, persistent HPV infection can result in epithelial lesions that can progressively develop into tumours. Tumour transformation occurs in only a few percent of infections, and mild epithelial lesions usually heal spontaneously. Malignant tumours can be expected to develop on average 5-10 years after the onset of infection. Low-risk HPV types cause benign but often difficult to treat warts (condyloma acuminatum). An endometrial epithelium is a multi-layered squamous epithelium. In the precancerous state, abnormal lesions appear only in the lower cell lines of the epithelium (AIN I / L-SIL). These lesions heal spontaneously in 90% of cases, but in a proportion of cases the abnormal process progresses to the middle cell lines and then the epithelium becomes affected throughout its thickness (AIN II-III /H-SIL). In this state, spontaneous healing is observed in less than half of cases. The chances of cure are lower in cases with a history of HPV infection over many years, multiple HPV virus infections, over 30 years of age, immunodeficiency and smoking. If not treated in time, the abnormal epithelium will break through the underlying basement membrane and spread to the connective tissue under the epithelium. From then on, we talk about anal squamous cell carcinoma. Given that the process of tumour transformation takes years, screening offers the possibility of early detection and timely treatment of epithelial lesions.
Vaccinations
Currently available vaccines protect against the HPV types that cause the highest incidence of cancer and warts.
Natural infection does not lead to lasting protection against re-infection.
Vaccines contain a protein envelope portion of the human papilloma viruses, which are artificially produced to induce adequate levels of antibody production and durable immunity in the body.
Since the vaccines do not contain viral DNA, they cannot cause infection or disease. The vaccine is extremely safe and the most common side effects are swelling, redness and pain at the injection site.
No serious complications are expected.
The nine-component vaccine (Gardasil 9), which protects against low-risk genital wart-causing HPV strains 6 and 11 and high-risk HPV strains 16, 18, 31, 33, 45, 52 and 58, may be able to prevent 90% of cancers.