Prostatic intraepithelial neoplasia is a pathological condition accompanied by the formation of foci of growth of prostate cells with signs of their atypical degeneration. It is asymptomatic. It is considered by specialists as a morphological precursor of prostate cancer with a high probability of malignant transformation. The diagnosis is made taking into account the data of finger rectal examination, ultrasound, determination of the level of prostate-specific antigen and the results of histological examination. Dynamic observation is shown. Diet therapy, hormone therapy and radiation therapy can be used.
Meaning
Prostatic intraepithelial neoplasia (PIN) is an obligate precancer of the prostate gland, accompanied by focal proliferation of the epithelium of the ducts and acinuses of the prostate with the formation of cells with signs of atypia. According to various data, it is detected in 8-50% of patients referred for puncture biopsy of the prostate gland due to suspected prostate cancer. The probability of occurrence increases with age. When examining patients aged 40-50 years, signs of prostatic intraepithelial neoplasia are detected in 14-18% of cases, at the age of 80 and over – in 63-86% of cases. The peak incidence occurs at the age of 65 years. Prostate adenocarcinoma develops on average 5 years after PIN detection. At the same time, both rapid malignancy and long-term stable course without signs of further malignancy are possible. The probability of malignant degeneration, according to various authors, is observed in 35-100% of cases. The treatment is carried out by specialists in the field of oncology, urology and andrology.
Causes
The causes of the development are not exactly clarified. Experts point out that unfavorable heredity plays a certain role. BRCA1 and BRCA2 genes are often detected in patients, in which there is an increase in the likelihood of developing prostate adenocarcinoma. The risk of IDUs also increases with chronic prostatitis and a history of sexually transmitted infections.
Ionizing radiation, prolonged contact with cadmium in the performance of professional duties, the use of large amounts of animal fats, lack of ultraviolet rays due to prolonged stay in the northern regions, old age, immune disorders, lack of certain vitamins and trace elements are indicated as risk factors for prostatic intraepithelial neoplasia.
Classification
The classification of this pathological condition has undergone repeated changes. Initially, experts identified three degrees of IDU: mild moderate and severe. Then, due to difficulties in determining the degrees of damage, a simplified classification with two groups of IDUs was adopted in 1989: low and high degree. The low (first) degree was characterized by minor cell changes, could indicate a low risk of malignant transformation, observed with benign hyperplasia (adenoma) or chronic inflammation of the prostate gland. With a high (second) degree of prostatic intraepithelial neoplasia, cells with pronounced signs of atypia were detected in the prostate tissue.
Subsequently, this classification ceased to be generally accepted, although some specialists continue to apply this division into groups in clinical practice. Nowadays, most oncologists and urologists use the following classification of neoplastic changes in prostate tissue:
- Atypical hyperplasia (obsolete – PIN of the first degree). The probability of malignant transformation in this condition ranges from 15 to 20%.
- Prostatic intraepithelial neoplasia (obsolete – second degree PIN). The risk of malignant degeneration in this lesion is more than 85%.
- Cancer or cellular atypia. It is not considered as a variant of IDU, but it can be detected simultaneously with this disease.
The main signs of prostatic intraepithelial neoplasia are: violation of the structure of the epithelial lining of the ducts with the loss of a clear division into cellular layers, as well as characteristic changes in epithelial cells with an increase in nuclei and the appearance of large vesicular inclusions. Cells with small hyperchromatic nuclei are less frequently detected. In the central or peripheral part of the nuclei, several nucleoli of a homogeneous or heterogeneous structure may be detected. Taking into account the features of the histological structure, there are 4 forms of prostatic intraepithelial neoplasia: bundle, flat, cribriform and micropapillary. The beam form is observed in 97% of cases. Usually, when studying a drug, a combination of several forms is found.
Diagnosis and treatment
The diagnosis of PIN is made after a puncture biopsy and subsequent histological examination in connection with suspected prostate adenocarcinoma. Along with a biopsy, a finger rectal examination of the prostate, transrectal ultrasound of the prostate gland and determination of the level of prostate-specific antigen (PSA) in blood plasma are performed during the examination. If atypical hyperplasia (PIN of the first degree) is detected, the decision to carry out subsequent diagnostic measures is taken individually. Depending on the patient’s age and the results of other studies, both dynamic observation and repeated biopsy are possible. If prostatic intraepithelial neoplasia (second-degree PIN) is detected after 1-3 months, an extended biopsy with sampling of material from 12 or more areas of the prostate gland is indicated.
The management tactics of patients are also determined individually. All patients with histologically confirmed ID are indicated for follow-up by a urologist. PSA tests are prescribed monthly. Transrectal ultrasound of the prostate gland is performed every six months. Repeated biopsy is performed at least once a year, with alarming results of other diagnostic procedures, an unscheduled examination is necessary. The indication for radiation therapy is the presence of a high degree of IDP in combination with a progressive increase in the level of PSA in the blood.
In addition, patients with prostatic intraepithelial neoplasia are prescribed hormone therapy to neutralize the effect of testosterone on altered epithelial cells. Buserelin, leuprorelin, nilutamide, flutamide, finasteride and other drugs are used. Patients are recommended to give up bad habits, follow a diet with a reduced content of animal fats, a large amount of vitamins and trace elements. Experts note that the tactics of treatment of prostatic intraepithelial neoplasia is currently under development, and in the future it is possible to change approaches to the treatment of this condition.
