What is a Prostate Tumor?

According to pathology, it is divided into prostate cancer derived from prostate epithelium and prostate prostate mesenchymal prostate sarcoma.

Song Gang	(Deputy Chief Physician)	Department of Urology, Peking University First Hospital
Zhou Liqun	(Chief physician)	Department of Urology, Peking University First Hospital

Prostate tumors include tumors of prostate epithelial or mesenchymal origin, most of which are malignant tumors, including prostate cancer and prostate sarcoma. Prostate cancer patients are mainly elderly men. Symptoms such as hematuria and dysuria may be present. However, since a large number of serum prostate specific antigen (PSA) tests were carried out in the mid-1990s, more and more early prostate cancers have been detected, and often no symptoms are present. Prostate sarcoma occurs in young people, the incidence is not high, and dysuria is the first symptom. The disease is extremely malignant, the disease develops very fast, and the prognosis is very poor.

Western Medicine Name: Prostate tumor
Affiliated Department: Surgery-urology

Disease site: prostate
Main cause: still uncertain
Contagious: Non-contagious

Prostate tumor disease classification

According to pathology, it is divided into prostate cancer derived from prostate epithelium and prostate prostate mesenchymal prostate sarcoma.

Causes of prostate tumors

Like many other tumors, the direct cause of prostate cancer is unknown. But according to existing literature, one of the most important factors is heredity. Patients with prostate cancer in the family are several times more likely to develop prostate cancer than other healthy people. Currently, many researches on the molecular etiology of prostate cancer are underway, which will provide genetic evidence to explain the occurrence of prostate cancer.

It cannot be ignored that exogenous factors also play a very important role in the pathogenesis of prostate cancer. Such as high animal fat diet, lack of exercise, excessive intake of cured meat products. In recent years, the incidence of prostate cancer in China has increased year by year, and one of the reasons is related to high animal fat diet. Exposure to sunlight can prevent prostate cancer because sunlight can increase vitamin D levels, which may be a protective factor for prostate cancer. In Asia, where prostate cancer is low, the consumption of green tea is relatively high, and green tea may be a preventive factor for prostate cancer.

Prostate tumor pathogenesis

Recently, research on how the normal prostate epithelial cells are transformed into metastatic, androgen-independent cancer cells has made significant progress at the molecular level. Cell dynamics, germ cell line mutations, DNA methylation, inactivation of tumor suppressor genes and oncogene activation, androgen receptor mutations, growth factors, and epithelial-matrix interactions all play important roles in the development of prostate cancer effect.

Prostate tumor pathophysiology

Prostate cancer mainly occurs in men over 50 years of age. Most of them occur in the acinar gland duct epithelium of the peripheral gland or posterior lobe. The pathological type is mainly adenocarcinoma, accounting for the vast majority, followed by transitional cell carcinoma, and very few squamous cell carcinoma.

Pathological classification: Gleason system is most widely used. Based on the degree of tumor gland differentiation and the growth pattern of the gland matrix, it divides the primary primary lesions into grades 1-5, and the secondary lesions are also divided into grades 1-5. Grade 1 differentiation is the best. Grade 5 differentiation is the worst. The sum of the two grades is the score obtained from the histological score, which should be 2-10 points. A score of 2-5 is highly differentiated, 6-7 is moderately differentiated, and 8-10 is poorly differentiated. The higher the score, the higher the malignancy of the tumor and the worse the prognosis.

Other pathological types of prostate tumors:

(1) Ductal carcinoma: Early known as "male endometrial cancer", because this tumor originates from a prostate sac similar to the endometrium, it has the histochemical and ultrastructural characteristics of the prostate, and does not originate from Wolff's canal .

(2) Sarcoma: Non-epithelial tumors account for less than 0.1% of prostate cancers. In children and adolescents, the urogenital system is the second most common site of rhabdomyosarcoma, after the head and neck. In the elderly, most sarcomas are leiomyosarcoma, and the prognosis is better than rhabdomyosarcoma.

(3) Carcinosarcoma: refers to the presence of both cancer and sarcoma in the same area of the tumor. This kind of tumor is highly malignant and has a very poor prognosis. Such medical records are rarely reported.

(4) Secondary prostate tumors: The prostate rarely has secondary metastatic tumors, so such tumors are rare. However, some studies have reported that melanoma can often metastasize to the prostate, causing secondary tumors of the prostate.

Clinical manifestations of prostate tumors

Most prostate cancers are asymptomatic in the early stages, and a few may have symptoms of early urinary obstruction, and some may have specific symptoms in the later stages.

Local manifestations of prostate tumors

When the tumor grows to obstruct the urinary tract, bladder neck obstruction symptoms similar to benign prostatic hyperplasia can occur. It is manifested by gradually increasing urinary flow, urinary frequency, urgency, interruption of urinary flow, endless urination, and dysuria. Cancer causes dysuria and hematuria is often advanced. Urinary incontinence can occur when the lesion extensively invades the urethral membrane, and invasion of the envelope and nearby lymph nodes around the nerve can cause compression of the local pain, and compression of the sciatic nerve can cause radiation pain in the lower limbs. Defecation difficulties may occur when the rectum is compressed. When the ureter is obstructed due to tumor metastasis along the lymph nodes, it may show back pain and hydronephrosis, and oliguria and renal failure may occur on both sides. Prostate ductal cancer and transitional cell carcinoma often appear painless hematuria with frequent urination and difficulty urinating. Hematospermia may occur when the tumor invades and seminal vesicles.

Distant metastatic symptoms of prostate tumors

Bone metastasis is a common symptom of prostate cancer, and some patients seek medical treatment with symptoms of metastases, without local primary symptoms of the prostate. Any bone can be invaded. The pelvis and lumbar vertebrae are the most common sites of early metastasis, followed by the thoracic spine, ribs, and femur. Symptoms of bone metastases are persistent bone pain, which is more pronounced when resting, and can cause pathological fractures and even paraplegia. Other metastatic symptoms include subcutaneous metastatic nodules, hepatomegaly, lymphadenopathy, lower limb edema when lymphatic return of the lower limb is blocked, neurological dysfunction caused by brain metastasis, cough, hemoptysis, chest pain, etc. that may occur during lung metastasis. Patients with advanced stages may show signs of loss of appetite, weight loss, fatigue, and anemia.

Prostate cancer diagnosis

The diagnosis of prostate cancer includes staging and histological types, which are mainly based on pathological examination of prostate biopsy or prostate surgery specimens, and other imaging examinations. Imaging examination can provide basis for staging of prostate cancer. The current diagnosis process of prostate cancer is as follows: serum PSA screening or digital rectal examination of patients, patients with elevated PSA or digital diagnosis of suspicious patients, prostate biopsy under ultrasound guidance, combined with imaging examination to determine the clinical stage, In order to determine the principles and methods of treatment.

Digital rectal examination of prostate tumors

Of all prostate cancer examinations, digital rectal examination is the simplest and most effective method of examination, especially for asymptomatic patients. Serious and careful digital rectal examination is of great significance for the diagnosis and staging of prostate cancer.

PSA Prostate tumor prostate specific antigen (PSA)

PSA is the most specific tumor marker for prostate cancer. It is a serine protease secreted by prostate epithelial cells. Its half-life is about 3.15 days. Many studies have shown that the normal range of PSA in the clinical range of 0 ~ 4ng / ml is used as a standard for screening for prostate cancer. PSA is only a marker for prostate epithelial cells, not a marker for prostate cancer cells. In addition to prostate cancer can cause elevated PSA levels, benign prostatic hyperplasia, prostatic inflammatory lesions, and infarction can all increase it. There are a number of different PSA indices to correct them, as briefly described below:

1. Free PSA (F-PSA) to total PSA (T-PSA) ratio (F / T): When the total PSA level is between 4 ~ 10 ng / ml, F / T can be used to identify benign and malignant prostate cancer. Unnecessary biopsies are significant. Domestically, 0.16 is used as the cut-off value.

2. PSA speed (PSAV): PSAV refers to the average annual increase rate of PSA level. Some people have proposed to use the PSAV value of 0.75ng / ml / yr as a reference index to identify benign and malignant.

3 PSA density (PSAD): PSAD refers to the PSA content per unit volume of prostate tissue, and is the ratio of PSA value to prostate volume. When the serum PSA level exceeds the upper PSA limit for the volume of prostate, the presence of prostate cancer should be suspected. Because PSAV is greatly affected by prostate volume measured by B-mode ultrasound, its clinical application has certain limitations.

PAP Prostate tumor prostate acid phosphatase (PAP)

Acid phosphatase is widely present in the prostate, liver, spleen, and red blood cells. Acid phosphatase in male serum mainly comes from the prostate. The acid phosphatase produced by prostate epithelial cells is called prostate acid phosphatase, and most of it is secreted into semen, and a small part enters the blood circulation. It is mainly used for monitoring and follow-up before and after prostate cancer treatment.

B B-ultrasound for prostate tumors

Ultrasound is a non-invasive method that can detect nodular changes in the prostate earlier, which is helpful for the early diagnosis of prostate cancer and continuous observation of the treatment effect. Ultrasound can be performed through the abdomen, urethra, and rectum, especially with rectal examination. Ultrasound examination of prostate cancer is typically characterized by hypoechoic space occupying the periphery of the prostate. Ultrasound is currently an important method for the diagnosis and staging of prostate cancer.

Prostate tumor prostate system biopsy

Transrectal or transperineal prostate biopsy under ultrasound guidance has become a routine clinical examination.

Prostate tumor isotope bone scan

Whole body isotope bone scan can find bone metastases of prostate cancer. It is reported in the literature that bone metastases can be found about 6 months earlier than X-rays. However, due to its high false-positive rate, caution should be used in the diagnosis.

X Prostate tumor x-ray

Chest and bone X-ray examination of patients with prostate cancer can detect lung and bone metastases.

CTMRI CT and MRI of prostate tumors

Both methods can show the anatomical relationship between the prostate and surrounding tissues. Generally, qualitative diagnosis cannot be performed, but only as a method of staging diagnosis. Both have limitations for the diagnosis of early lesions. It is generally believed that MRI has more diagnostic value and more accurate staging than CT. Recently, there are reports that bone metastases are found earlier than bone scans by MRI. Therefore, patients should be examined clinically by bone scans, and MRI examinations should be performed to confirm the diagnosis after suspicious metastases are found.

Prostate tumor emergency measures

Urinary catheterization can be performed urgently when urinary retention occurs in advanced prostate cancer.

Prostate cancer disease treatment

The treatment of prostate cancer must be different from person to person, and the treatment method must be adapted to the patient's life expectancy, social relationship, family and economic status. Surgery and radiotherapy alone are currently promising to cure prostate cancer, and are only suitable for a limited number of patients. Many therapies are only palliative and can only relieve symptoms. However, due to the longer natural course of prostate cancer patients, the relatively slow tumor growth rate, and the shorter life expectancy of the elderly, the relief of the disease means cure for many patients. Based on the commonly used clinical Jewett-Whitmore-Prout staging system, the treatment methods of tumors in each stage are briefly described below.

Various treatments for prostate cancer:

Close follow-up observation of prostate tumor

It is suitable for patients with stage A1. Blood PSA levels and corresponding imaging examinations are regularly reviewed to determine whether the patient's disease has progressed.

Prostate cancer endocrine therapy

Prostate cancer is divided into hormone-dependent and non-hormonal-dependent types, which account for about 90% and 10%, respectively. At present, the first-line endocrine therapy generally accepted is total hormone blocking therapy, that is, drug castration (LHRH agonist) or surgical castration (testectomy removal) plus anti-androgen drugs. Followed by pure castration therapy, patients with drug castration must also take anti-androgen drugs for one month at the same time to avoid the deterioration of testosterone levels. Secondly, antiandrogens are used alone.

Prostate tumor radiotherapy

Radiotherapy can achieve the goal of curing prostate cancer, although only some patients. It is widely used at home and abroad. Its more serious complications such as radiation proctitis, irritation caused by cystitis and ulcers. Radiation therapy includes internal radiation therapy, external radiation therapy and palliative radiation therapy. In recent years, more internal radiation therapy (particle implantation) has been carried out abroad. The therapeutic effect can be achieved by placing small radioactive rods uniformly in the prostate under B-mode or CT monitoring. Local radiotherapy for bone metastases can relieve bone pain caused by metastases.

Prostate cancer chemotherapy

In recent years, people have begun to pay attention to chemotherapy for prostate cancer. At present, chemotherapy is mainly used as adjuvant therapy for advanced prostate cancer in the treatment of prostate cancer.

Prostate tumor surgery

Including radical surgery and palliative surgery. Palliative transurethral resection of patients with advanced tumors to remove their bladder and neck obstruction is feasible only to alleviate the symptoms of obstruction and improve the quality of life of the patients. There is no cure. Radical prostatectomy can be performed on patients with clinical stages A2, B, and even C1, including nerve-sparing radical surgery, expanded radical surgery, etc. The surgical approach can be performed through the posterior pubic bone, through the perineal open surgery, and through the abdominal cavity Microscopic radical resection, but surgery is limited to patients with a life expectancy greater than ten years.

Cryotherapy for prostate tumors

In the early days, it was mainly used to treat benign prostatic hyperplasia, and later it was gradually used to treat prostate cancer. Local cryotherapy can be transurethral or perineal, and can directly reach the primary tumor lesion. It is possible to completely eliminate local tumor tissue without extensively removing the tissue. The main complication is temporary urethral skin fistula.

Treatment of prostate cancer

The treatment of prostate cancer has been described above, and the specific application of each stage of tumor is briefly described as follows:

Stage A1: Close follow-up observation.

Stage A2, B: Patients aged 73 years, radical prostatectomy + adjuvant radiotherapy or chemotherapy; patients age> 73 years, endocrine therapy + adjuvant radiotherapy or chemotherapy.

Stages C and D: Endocrine therapy + adjuvant radiotherapy or chemotherapy, of which stage C1 can determine whether a radical prostatectomy is feasible depending on the specific circumstances of the patient.

Specific methods of endocrine therapy:

At present, most scholars believe that the best effect of endocrine therapy is hormonal blockade. According to the efficacy of different endocrine therapies, they are ranked from strong to weak and combined with the patient's acceptability: LHRH agonist + antiandrogenic drug orchiectomy + antiandrogenic drug LHRH agonist alone (additional one month Anti-androgen drugs to avoid the deterioration of the serum testosterone rebound) orchiectomy anti-androgen drugs alone.

Prostate sarcoma occurs in young people, has a high degree of malignancy, and has a very poor prognosis. Femoral tumor resection or even total pelvic organ resection is feasible. ^[1-2]

Prognosis of prostate tumor disease

Prostate tumors generally develop slowly and have a good prognosis. Long-term survival can be achieved by active treatment of early prostate cancer.

Prostate cancer disease prevention

Eat less red meat (pork, beef, lamb, etc.) and eat more white meat (chicken, fish, etc.) to reduce fat intake.

Prostate cancer disease care

1) Because prostate tumors are mostly elderly patients and suffer from hypertension and cardiovascular disease, attention should be paid to changes in blood pressure and pulse of patients, and follow-up should be conducted in a timely manner.

2) Strictly grasp the best timing for urinary catheterization; domestic urinary catheterization should be about 3 weeks after surgery, but the difference between hospitals and doctors is large, and you should follow the doctor's advice.

3) Intensify nursing after extubation: urinary incontinence may occur after surgery, so you should pay attention to pelvic floor exercise. If necessary, apply artificial sphincter therapy.