Prostate cancer

　　Genetic changes can lead to prostate cancer, and genetic changes may also be related to environmental factors such as diet. The more genetic changes, the greater the risk of developing prostate cancer. In a few cases, prostate cancer may be hereditary.

　　1. Age

　　Age is the main risk factor for prostate cancer. Prostate cancer is very rare in men under 45 years of age, but the incidence of prostate cancer increases sharply with age, and the age of the vast majority of patients with prostate cancer is greater than 65 years.

　　2. Family history

　　When there is a first-degree male relative with prostate cancer in the family, the incidence of prostate cancer in the family will increase significantly. First-degree male relatives generally refer to fathers and brothers.

　　3. Race

　　The incidence of prostate cancer is highest among African Americans (i.e., black Americans), followed by Hispanics and white Americans, while the incidence of prostate cancer among African blacks is the lowest in the world.

　　4. Pathological changes of abnormal cells in the prostate

　　Males with high-grade prostatic intraepithelial neoplasia have a significantly increased incidence of prostate cancer. High-grade intraepithelial neoplasia is a precancerous lesion, which shows abnormal cell growth morphology under the microscope. Although it does not belong to cancer, it often indicates the presence of prostate cancer, but it has not been detected yet.

　　The common complications of prostate cancer mainly include lymph node metastasis and distant metastasis, among which bone metastasis is common, second only to lymph node metastasis.

　　1. Lymph node metastasis

　　The first lymph nodes to be invaded by prostate cancer are the obturator-iliac internal chain. In fact, the lymph nodes at the obturator site are generally not invaded. Clinically, the iliac internal lymph nodes are often referred to as obturator lymph nodes, located on the inside of the iliac external vein, and along the course of the iliac internal vessels are the most important lymph nodes to be removed.

　　The diagnosis of lymph node metastasis in recent years relies on CT and MR, but it cannot detect small lesions. Lymphography can detect 70% to 90% of metastases. However, the false-negative and false-positive rates are high, and it is less commonly used in recent years. The most valuable diagnostic method is the modified lymph node dissection, which is the removal of lymph nodes between the iliac internal and external vessels and obturator, which is more precise for staging and can avoid complications such as lymph leakage, lymph edema, and lower limb edema caused by previous lymph node dissection of the iliac vessels, obturator, pelvic wall, and iliac anterior lymph nodes, because even extensive dissection cannot prevent existing spread.

　　2. Distant metastasis

　　When venous urography detects ureteral obstruction, it indicates that the tumor has invaded the seminal vesicle, bladder neck, and lymph nodes, and there is a possibility of distant metastasis. Bone metastasis is common, second only to lymph node metastasis. Enhanced whole-body isotope scanning with normal plain films should be considered as metastasis. Lung X-ray photography can detect lung metastasis, which is often lymphatic spread, and nodular metastasis is rare.

　　In the early stages of prostate cancer, due to the tumor being localized, most patients with prostate cancer have no obvious symptoms and are often discovered incidentally during physical examinations, or may be found in surgical specimens of benign prostatic hyperplasia. As the tumor continues to develop, prostate cancer will present with a variety of different symptoms, mainly with three aspects of performance:

　　1. Obstructive symptoms

　　There may be difficulties in urination, urinary retention, pain, hematuria, or incontinence.

　　2. Local infiltrative symptoms

　　The interspace between the bladder and rectum is often the first to be affected, which includes organ structures such as the prostate, seminal vesicle, vas deferens, and lower end of the ureter. If the tumor invades and compresses the vas deferens, it can cause back pain and pain in the testicle on the affected side, and some patients may also report pain during ejaculation.

　　3. Other metastasis symptoms

　　Prostate cancer is prone to bone metastasis, which may initially have no symptoms. Some patients may discover prostate cancer when seeking medical attention for symptoms caused by bone metastasis, such as nerve compression or pathological fracture.

　　There is no effective treatment for prostate cancer, so prevention in daily life is very important.

　　1. Screening

　　The commonly accepted effective method is rectal examination combined with serum PSA concentration measurement. Serum PSA levels are detected in male citizens aged 40 to 45, and a follow-up measurement is conducted annually. This screening method is both economical and effective. If PSA exceeds 4.0 ng/ml, rectal examination or ultrasound examination should be performed, and if positive or suspicious, needle biopsy should be performed. This method can effectively detect early localized prostate cancer. A population-based screening study in Sweden found that the time span from an increase in serum PSA concentration above 3ng/ml to a clinical diagnosis of prostate cancer is 7 years. Therefore, population-based PSA screening can enable early diagnosis and early treatment of prostate cancer.

　　2. Avoid risk factors

　　This is very difficult to achieve. Because there are many clear risk factors, such as heredity and age, which are unavoidable. However, potential environmental risk factors such as high-fat diet, cadmium, herbicides, and other undetermined factors can be avoided. In addition, sticking to a low-fat diet, eating more soy products rich in plant protein, drinking Chinese green tea for a long time, appropriately increasing the content of trace elements selenium and vitamin E in the diet, and other measures can also prevent the occurrence of prostate cancer.

　　3. Chemical prevention

　　Chemical prevention can be divided into the following main categories according to the way of drug interference, such as tumor occurrence inhibitors, anti-tumor growth drugs, and tumor progression inhibitors, etc. Other drugs such as retinoids, which have the effects of promoting cell differentiation and inhibiting tumor progression, are also under clinical research and may become potential chemical prevention drugs.

　　The examination of prostate cancer mainly includes laboratory examination and imaging examination, among which imaging examination mainly includes ultrasound examination, X-ray examination, and CT or MRT examination.

　　First, laboratory examination

　　1. The increase of serum prostate-specific antigen (PSA), but about 30% of patients may not increase PSA, but fluctuate within the normal range (normal range

　　2. The increase of serum acid phosphatase is related to the metastasis of prostate cancer, but it lacks specificity. The acid phosphatase in the prostate cancer within the capsule is secreted by the prostate cells and excreted through the prostate duct. In prostate cancer, the acid phosphatase produced by the cancer cells has no ductal excretion or the duct is obstructed by the cancer lesion, and the enzyme is absorbed into the blood circulation, resulting in the increase of acid phosphatase.

　　Second, imaging examination

　　1. Ultrasound examination can show low echo nodules in the prostate, but it must be distinguished from inflammation or calculus.

　　1. Radioisotope bone scanning can often show metastatic lesions early, which is more common than X-ray film shooting.

　　2. CT or MRI examination can show changes in the shape of the prostate, tumor, and metastasis. The main CT manifestation of prostate cancer is the presence of a low-density area with unclear enhancement during enhanced scanning, and the capsule shows irregularity. When the tumor invades the bladder or the surrounding organs of the prostate, corresponding changes can appear in the pelvic CT. When there is metastasis of the pelvic lymph nodes, CT can judge whether there is metastasis according to the change in the size of the pelvic lymph node group.

　　To reduce the intake of fat in the diet, patients with prostate cancer should eat low-fat foods, low-fat dairy products, and add less oil to the food, and eat lean meat.

　　1. Eat more legumes and vegetables

　　Westerners have never had the habit of eating soy products, but there are indeed cancer-fighting agents in the soy products that Asian people like to eat. Isoflavones in soybeans can reduce the destructive effects of androgens and inhibit and kill cancer cells. Westerners eat too few vegetables, and they should eat a variety of vegetables like the Japanese and Chinese people do. In addition to Chinese cabbage, vegetables such as cauliflower and broccoli also have the effect of preventing and treating prostate cancer. In addition, a little flaxseed and tomatoes can be eaten every day. Tomatoes contain lycopene, which has a preventive and therapeutic effect on prostate cancer.

　　2. Drinking Tea

　　Related research also shows that the habit of drinking green tea among Asians plays a certain role in the prevention and treatment of prostate diseases. The effect of green tea becomes more pronounced as the amount and time of drinking tea increase. Western men generally drink alcohol before and after meals, which is easy to cause prostatic congestion. German experts suggest that people can drink tea like Asians during meals, and even if they drink alcohol, they should only drink some low-alcohol red wine.

　　3. Calcium Supplementation

　　Inhaling more than 2000 milligrams of calcium daily can increase the risk of prostate cancer by three times. However, in order to maintain bone health and prevent osteoporosis, a moderate amount of calcium is necessary daily, and it is recommended to inhale 1000 to 1200 milligrams of calcium daily.

　　The main methods of Western medicine in the treatment of prostate cancer are external beam conformal radiotherapy, brachytherapy, cryotherapy, and chemotherapy. Patients can choose an appropriate treatment method according to their condition under the guidance of their doctor.

　　1. External Beam Conformal Radiotherapy (EBRT)

　　It is a new method of applying external beam radiotherapy to prostate cancer, which can reduce the adverse reactions of traditional external radiotherapy and improve the therapeutic effect by increasing the maximum dose of radiation to the prostate area while reducing the dose of radiation to the surrounding tissues of the prostate.

　　2. Brachytherapy (近距离放疗)

　　Brachytherapy is a treatment method that implants radioactive particles into the prostate through the perineal skin, and kills prostate cancer through近距离 radiation. Due to its minimal damage and the fact that it usually does not require other treatment assistance, it is also one of the curative treatments for prostate cancer.

　　3. Cryotherapy

　　Cryotherapy is a minimally invasive treatment method, which guides the probe through the perineal skin into the prostate under ultrasound guidance, and then injects liquid nitrogen at -96 degrees Celsius into the probe to freeze and kill tumor cells.

　　4. Chemotherapy

　　Chemotherapy is used to treat patients with metastatic prostate cancer that is resistant to endocrine therapy, with the aim of delaying tumor growth and extending the life of the patient.