Overview
Prostate cancer is the most common malignant tumor of the male genital system, and its incidence increases with age, with significant regional differences and higher incidence in Europe and the United States. After lung cancer, it is reported to be the second most common cancer death in men. The incidence of prostate cancer in China used to be low, but due to the aging of the population, the incidence has increased in recent years. Meanwhile, due to the continuous improvement of diagnostic methods for prostate cancer, such as radioimmunoassay of acid phosphatase, determination of lactate dehydrogenase in prostate fluid, transrectal ultrasound imaging, CT examination and improvement of prostate puncture needle, prostate cancer can be diagnosed early and the incidence of prostate cancer has also increased.
Etiology and pathology
The etiology of prostate cancer has not yet been identified and may be related to genetics, environment, and sex hormones. The secretory function of the prostate is regulated by the androgen testosterone, and the gonadotropin luteinizing hormone plays an indirect role. Prostate cancer never occurs in juvenile castrators.
Prostate cancer is 98% adenocarcinoma, often occurring from the atrophic peripheral part of the prostate, and most are multifocal. The metastatic pathway of this disease has three ways: (1) infiltrate to the nearby tissues or adjacent organs, firstly invade both lobes, penetrate the peritoneum to the vas deferens, seminal vesicles, bladder neck and posterior urethra; (2) lymphatic metastasis can reach the lymph nodes adjacent to the abdominal aorta inside and outside the skeleton, etc.; (3) hematogenous metastasis is most common to the bone poor, spine and femur. Severe pain and pathological fractures may occur. It can also metastasize to liver, lung, pleura, adrenal gland, brain and other internal organs.
Prostate cancer can be divided into four categories as follows
(1) Latent prostate cancer: It is an adenocarcinoma originating from the prostate gland that has no symptoms and signs of prostate disease during life and is detected by pathological examination during post-mortem examination. Latent cancer can occur in any part of the prostate, but it is more common in the central and peripheral areas, and is often a well-differentiated adenocarcinoma. Its incidence rate is reported to be 15% to 50% abroad. In China, the incidence of latent prostate cancer was reported to be 3-4% by the Institute of Urology, North Medical University.
The incidence of latent prostate cancer is reported to be 3-4%. Statistical studies show that the incidence of latent prostate cancer may be related to environmental and genetic factors.
(2) Incidental prostate cancer: The main clinical symptom is benign prostatic hyperplasia, and prostate cancer is found in the histological examination of the excised hyperplastic prostate tissue. The incidence of incidental carcinoma of the prostate is 10% to 30% in foreign countries. The incidence of incidental carcinoma of the prostate in foreign countries is 10%-30%. The incidence in China has been reported to be about 5%.
(3) Occult prostate cancer: Patients do not have symptoms and signs of prostate disease, but pathological examination of specimens in lymph node biopsy or bone puncture confirms prostate cancer. It can be further confirmed by prostate puncture biopsy. In these patients, serum prostate-specific antigen (PSA) and prostatic acid phosphatase levels are elevated. The biopsy tissue is positive for PSA and/or PAP immunohistochemical staining.
(4) Clinical cancer of prostate: clinical examination (fingerprick, ultrasound, CT or MRI, etc.) is diagnosed as prostate cancer and can be confirmed by biopsy. The diagnosis can also be assisted by the patient’s increased serum PSA and PAP. In most patients, prostate nodules can be palpated by anal diagnosis, and ultrasound examination indicates irregular shape of prostate nodules with uneven and hypoechoic echogenicity.
Clinical manifestations
The clinical presentation varies widely and is related to the tumor staging. The latent and insidious types have no local symptoms. The clinical type has local symptoms similar to those of prostatic hyperplasia.
The early stage is asymptomatic. When the cancer causes obstruction of the bladder neck and posterior urethra, symptoms can appear, hematuria is less common, and some patients are seen with metastatic symptoms, manifested as low back pain and sciatica. Therefore, prostate cancer should be excluded in men with metastatic cancer of unknown primary focus.
Invasion of the posterior urethra of the bladder neck with inflammatory symptoms of urethral stricture, urinary frequency, urinary urgency, urinary pain, hematuria and difficulty in urination.
Patients have chronic wasting symptoms, wasting, weakness and anemia.
In the early stages, the patient is not at all characterized. As the disease progresses, the patient may notice the following.
1. frequent and urgent urination
2.Urinary retention
3.Pungent sensation during urination
4.Difficulty in forming a urine stream
5.Hematuria
6.Painful urination
7.Bone pain
Patients who have advanced prostate cancer may also have the following complications.
1.Bone marrow depression
2.Metastasis of bone tumor
3.Paraneoplastic syndrome
4.High calcium content
5. Pain
6.High uric acid
7.Pleural leakage
8.Swollen legs
The effect of testosterone on prostate cancer
Doctors believe that this method is not feasible, but may become a high risk group for prostate disease. If you have prostate cancer and then try to improve your sexual function with testosterone, it will also aggravate your condition.
The symptoms of prostate cancer are almost the same as those of prostate hypertrophy, and about 2% of prostate hypertrophy will deteriorate into cancer; men over 50 years old are more likely to develop prostate cancer. However, with early detection and treatment, the survival rate is much higher than other cancers.
Insufficient testosterone secretion will affect the development of sexual organs and sexual function, so it is best to seek medical advice and appropriate testosterone treatment will improve the situation. Once you have prostate cancer, if you take testosterone again, your condition will worsen.
Prostate cancer is treated with surgery, radiation, and in advanced stages, hormone therapy or orchiectomy.
Diagnostic methods.
①rectal finger examination: hard nodules are found, with a correct rate of 80%;
② Transrectal puncture or trans-perineal incisional prostate biopsy is more accurate;
③Serum acid phosphatase measurement: it can be significantly increased.
④B ultrasound, isotope scan: prostate are changed.
⑤ X-ray: urethral bladder neck displacement after urography; spine, pelvis, femur and sternum radiographs, metastatic bone destruction lesions are seen.
Early diagnosis of prostate cancer
Since prostate cancer mostly occurs in the posterior lobe, there are no symptoms in the early stage, and even if there is discomfort, it is not enough to attract the patient’s attention, thus making early diagnosis difficult. Once the symptoms appear clinically, the disease is often at an advanced stage and the prognosis is poor. Therefore, early detection of prostate cancer is very important. Especially for patients with prostatitis and prostate hypertrophy, the repeated attacks are not cured, so we should pay close attention to the changes of the disease to prevent cancer. In the early stage, patients with prostate cancer often have symptoms such as increased frequency of urination and nocturia, difficulty in urination, thinning of urine stream, prolonged urination, painful urination and urinary retention, which are the same as prostate enlargement, so it is difficult to diagnose prostate cancer based on this.
Rectal examination is very important in the early diagnosis of prostate cancer, and its accuracy rate can reach 50%-70%. Many scholars advocate that in areas with a high incidence of prostate cancer, regular rectal examination for men over middle age will give many patients a chance for early diagnosis and radical treatment.
If necessary, the doctor can take biopsy through perineum and rectum, and the correct rate of diagnosis can reach 70%-80%. It is also possible to massage the prostate through the rectum and collect the prostate fluid for examination, the positive rate of which can be more than 90%. The diagnosis can be confirmed in the vast majority of cases.
It is worth reminding that although the incidence of prostate cancer is not high, its symptoms are similar to those of prostate enlargement. If the condition worsens after treatment, the possibility of prostate cancer should be considered and the above mentioned tests should be done for early detection and early diagnosis.
Diagnosis of advanced prostate cancer
(1) The main symptom of advanced prostate cancer is lower urinary tract obstruction, or hematuria and urinary retention. The most prominent symptom is pain, and in case of bone metastasis, severe pain in the pelvic area or lumbosacral region. The main signs are hard nodules and masses in the prostate gland, which are hard and fixed without normal elasticity, and hard changes around the gland with unclear boundaries.
(2) X-rays show osteogenic changes in the bones, with increased density of bone shadows and loss of bone trabeculae.
(3) Cystogram shows enlarged prostate with disrupted urethral orifice or uneven margins.
(4) Prostate imaging shows destruction of the gland, obstruction of the ducts, and irregular enlargement of the shape.
(5) Cystoscopy can clarify whether the cancer has invaded the urethra or bladder.
(6) Positive results can be obtained by cancer cell examination of prostate fluid.
(7) Biopsy can obtain positive results.
(8) Serum acid phosphatase, bone marrow acid phosphatase and serum alkaline phosphatase may be measured and may be elevated in the case of bone metastasis.