The bladder is a cavernous organ, stretchable, with a wall layer composed mainly of muscle, whose function is to store urine. Urine comes from the kidneys bilaterally and flows into the bladder through the ureters and out through the urethra. The female urethra is shorter and opens in front of the vagina, while the male urethra is longer and passes through the prostate and penis. The surface of the bladder lumen is covered with a layer of migratory epithelial cells which also cover the surface of the renal pelvis, ureter and urethra.
I. Pathogenesis
Bladder cancer is the most common tumor in the urinary system, accounting for 3% of all tumors. It ranks eighth in the list of top ten malignant tumors in China. The incidence rate of bladder cancer in developed countries ranks second after prostate cancer among male genitourinary system tumors, while it takes the first place in China. The ratio of men to women is 4:1, and the age is mostly above 50 years old, with the peak at 70 years old. Bladder cancer is known as environmental tumor, which is closely related to the external environment.
Risk factors
Risk factors for the development of the disease include: environment, occupation, urinary tract infection and chronic inflammation, bladder stones, bladder foreign body, pelvic radiation therapy, etc. The corresponding risk occupations are: dye, textile, rubber, paint, truck driver, chemical, oil, hairdresser, aluminum factory, etc. The long-term action of intra-urinary carcinogenic substances on bladder mucosal epithelium is the main reason for the occurrence of bladder cancer.
1.Environmental factors: The incidence of bladder cancer is higher than the general population for those who have long-term exposure to aromatic substances, such as aniline, dyes, leather, printing, cosmetics, hair dyes, rubber, paints, pharmaceuticals, insecticides, etc. The average time from exposure to carcinogenic substances to disease is 16~22 years.
2.Smoking is another important cause of bladder cancer. The cause of 40%-85% of bladder cancer comes from smoking. Smoke contains substances that can cause bladder cancer, and smokers have higher levels of the carcinogen tryptophan in their urine. The incidence of bladder cancer in smokers is two to four times higher than that of nonsmokers. The incidence of bladder cancer is directly proportional to the amount of daily smoking and the age of smoking.
3.Chronic inflammation of bladder and stimulation of foreign body can increase the risk of bladder tumor, such as long-term chronic infection, bladder stones, virus, schistosomiasis, etc. It has been pointed out that if a carcinogenic substance exists in the urine, the incidence of bladder cancer may increase in those who have urinary retention or have the habit of holding urine.
4.Drugs: Cyclophosphamide can induce bladder cancer; excessive dosage of finasteride sedative can also increase the incidence of bladder cancer.
5.Genetic factors: It has been proved that bladder cancer is related to mutation of P53 gene and variation of chromosome 9. Such patients have obvious family history and the cause of development may be due to genetic defects, which make them easy to be affected by carcinogens in the environment. The age of onset is generally younger.
6.Coffee, saccharin and preservatives in food can increase the incidence of bladder cancer.
7.High cholesterol intake and certain substances in beverages are related to the development of bladder cancer.
8.Pelvic radiation therapy can increase the risk of bladder cancer.
9.Bladder cancer is closely related to gender, and the incidence rate of men is 2~10 times higher than that of women.
Abnormal manifestations
1.Hematuria: Painless, intermittent hematuria under the eyes or microscope is the typical symptom, accounting for 95%. It is mostly hematuria throughout the whole process and not aggravated at the end, but also the beginning or the end of hematuria. The amount of hematuria varies, and in severe cases, there are blood clots or necrotic decaying tissue, sometimes the bleeding can stop by itself, so that patients have the illusion that the disease has been cured, and no longer continue the treatment.
2.Bladder irritation symptoms account for 70%, manifested as urinary frequency, urinary urgency, urinary pain, intermittent and recurrent urinary tract infection, mostly due to tumor infiltration of bladder wall or secondary infection.
3. Difficulty in urination and urinary retention: when the tumor occurs in the bladder neck or blockage by blood clots can cause difficulty in urination and even urinary retention.
4. In the late stage, there are anemia, emaciation, fever, edema of lower limbs, abdominal mass, falling and pain in the small abdomen, perineum and anus, change of urination habit, and some patients may have abdominal pain.
Prevention of bladder cancer
1. Over 40 years old, especially men should pay attention to the color of urine and urination habits frequently.
2.Workers who are exposed to chemical dyes, chemicals and radiation for a long time should pay attention to strengthen occupational protection and have regular health checkups. Try to avoid unnecessary radiological examinations and exposure to chemicals such as arsenic, mercury, hydride, etc.
3.Prohibit smoking and alcohol.
4, cautious use of alkylating agents and certain immunosuppressants, strictly under the guidance of physicians to master the indications, dose and course of drugs.
5.Actively prevent chronic inflammation of the bladder.
6, daily after taking drugs should pay special attention to drink more water, to ensure that the daily water intake in more than 3000ml, in order to promote excretion, reduce the damage to the bladder.
7, change the habit of holding urine, to reduce the stimulation of harmful substances to the bladder.
8, reasonable diet, eat more food rich in vitamin A, B, C, less spicy, slippery products, reduce the intake of strong tea, coffee, drinks, cholesterol and saccharin.
9.When there is hematuria and difficulty in urination, go to a specialized oncology hospital for medical consultation in time.
V. Important signals of bladder cancer
1. Painless hematuria of the naked eye is the characteristic manifestation of bladder cancer. Most of the bladder cancers have painless hematuria as the first symptom, and the hematuria often reduces or stops on its own, which may cause the illusion that the disease has been cured and make patients take it lightly and delay the diagnosis and treatment. Therefore, even if painless hematuria occurs only once, you should be fully alert and thoroughly examined.
2.Microscopic hematuria, which should be paid full attention, has important value for early detection of bladder cancer.
3.Bladder inflammation-like symptoms such as increased frequency of urination, urinary urgency and painful urination should be alerted to the possibility of bladder cancer if it does not heal after anti-infection treatment for a long time.
4.If the tumor has invaded the ureteral opening, it can cause hydronephrosis and symptoms of back pain, lumbar pain and swelling. Therefore, for any suspicious symptoms of urinary system, one should be alert to the possibility of bladder cancer.
VI. Early detection of bladder cancer
Whether bladder cancer can be diagnosed early or not is crucial to the prognosis of patients. In order to detect and diagnose bladder cancer at an early stage, we should follow four recipes step by step, namely: “Abnormal urination should be alerted, initial screening of tumor by urinalysis, confirmation of diagnosis by cystoscopy, and comprehensive evaluation by imaging.”
The most common symptom of bladder cancer is hematuria without any feeling and visible to the naked eye, which is a unique “abnormal urination signal” of bladder cancer and occurs in almost every patient. Hematuria is most often seen throughout the urine, or only at the beginning or end of urination. The hematuria is often painless and intermittent, relieving or stopping on its own, making it extremely easy to create the illusion that the disease has healed. In addition, a small number of patients experience increased urination, urgency and painful urination like “cystitis”. Therefore, we should be alert to the possibility of bladder cancer if “cystitis” is not cured by taking antibiotics for a long time. When people have the above “abnormal urination signals”, especially painless hematuria, even if it only occurs once, they should be fully alert and investigate to the end.
A few patients with bladder cancer can have microscopic hematuria without visual hematuria, but only microscopic hematuria with excessive red blood cells. A very simple routine urine examination is valuable for early detection of bladder cancer when normal people pay attention to it during one to two whole body checkups per year. Most bladder cancers occur in the bladder mucosal epithelium, and tumor cells are easily mixed in the urine. Microscopic urine exfoliative cell examination is a simple, non-invasive and economical method for initial screening of patients with hematuria. Therefore, outpatient doctors should pay attention to routine urine microscopic examination and urine exfoliative cell microscopic examination.
3.Cystoscopy When a patient shows signs of abnormal urination, especially painless meatus hematuria, or repeatedly found microscopic hematuria, he should undergo cystoscopy. Cystoscopy is the only means to confirm the diagnosis of bladder cancer before surgery. The cystoscope is inserted into the bladder along the urethra to observe the whole bladder and the urethra at the same time to directly see the tumor site, size, number and infiltration degree, etc. If biopsy is taken at the same time, the nature of the tumor can be clarified.
Therefore, if it is clear that the patient has bladder cancer, it is necessary to perform intravenous urography to show the renal calyces, renal pelvis, ureter and ureter through intravenous injection of contrast agent to clarify or exclude the suspicious tumor. In addition, ultrasound and CT examinations can help assess the extent and depth of bladder cancer infiltration and the presence or absence of surrounding lymph nodes. Necessary imaging examinations are important for overall assessment of the disease and decision of treatment plan.