BCG is one of the legal vaccines in the immunization schedule and is required for every newborn baby to prevent tuberculosis. However, few people know that BCG vaccine has another purpose – to treat and prevent the recurrence of bladder tumors. Currently, 90% to 95% of bladder cancers are metastatic epithelial cell carcinomas, which are mostly superficial in the early stages of the disease. The treatment of superficial bladder cancer mainly relies on transurethral resection or electrocautery. However, after transurethral resection of superficial bladder cancer, the recent tumor recurrence rate is as high as 50% to 90%, and the long-term recurrence rate is almost 100%. Bladder irrigation with BCG after surgery is an effective way to treat and prevent recurrence of bladder cancer.
In 1976, Dr. Morales was the first to successfully treat recurrent superficial bladder cancer by direct injection of BCG into the bladder. Subsequently, doctors in various countries conducted numerous clinical observations and studies on the treatment and prevention of superficial bladder cancer with BCG, and the results showed that the complete remission rate of postoperative residual bladder cancer treated with BCG infusion ranged from 50% to 90% (average 70%), effectively reducing the recurrence rate of bladder cancer and delaying tumor recurrence and disease progression. Since BCG infusion is effective in treating and preventing bladder tumor recurrence, inexpensive and easy to use, without the common side effects of general anti-cancer drugs (such as leukopenia, anemia, nausea, anorexia, hair loss, etc.), it is very popular among patients and doctors.
Factors that affect the effectiveness of BCG infusion in the treatment and prevention of bladder cancer include: 1. The patient’s immune responsiveness. The stronger the patient’s immune response ability to Mycobacterium antigens, the more significant the therapeutic effect. BCG, unlike other anti-cancer drugs, is not a direct killer of cancer cells. Since BCG has the same antigen as the bladder tumor, BCG is used to treat bladder cancer by activating the mononuclear macrophage system in the patient’s body, increasing the cytotoxic effect of lymphocytes and producing anti-tumor antibodies, so that they can target and destroy the tumor tissue. Therefore, most of the patients who have positive tuberculin test have good response and therapeutic effect for the treatment of bladder cancer.
2.The number of live bacteria of BCG vaccine. It is found that BCG vaccine containing more than 7.5×108 live bacteria has better therapeutic effect, and preparations with less than this number have poorer therapeutic effect.
3, the number of times of medication. It is generally believed that the treatment effect is better for those who use the drug more than 8 times, and the treatment effect is worse for less than 8 times. Some patients are forced to stop the medication for various reasons, which is difficult to achieve the expected effect.
4.The type and size of tumor. BCG infusion is only effective for recurrence of superficial bladder cancer and treatment of residual cancer and carcinoma in situ, but not effective for bladder cancer infiltrating the muscular layer. The treatment is effective for those whose cancer is less than 0.5 cm in diameter. If the tumor size is too large, it will destroy the body’s immune ability and make the body lack sufficient immune active cells and affect the treatment effect. In addition, the tumor body is too large for BCG vaccine to be in close contact with the tumor extensively, resulting in part of the tumor tissue not getting the stimulating effect of inflammation and losing the effect of BCG vaccine to enhance immune function, which affects the therapeutic effect.
Usage of BCG bladder irrigation: After surgical resection of bladder tumor, use 100~150mg BCG, dilute with 50~60ml saline during irrigation, and irrigate once a week for 6 times. Later, irrigate once or twice a month, depending on the patient’s condition, for a total of 8 to 12 times. After irrigation, the patient should take a sitting position so that the drug can fully interact with cancer cells in the bladder and be retained for two hours, and then urinate. The common side effects after BCG infusion include urethral irritation, fever, chills, loss of appetite and hematuria. In addition, epididymal tuberculosis, bladder contracture and periurethral granuloma can occur in some individuals. The vast majority of side effects are self-limiting. Most serious complications can be cured after discontinuation of the drug or with the addition of anti-tuberculosis drugs. Most of these irritations and complications have been reported to be prevented if oral isoniazid is started on the same day as BCG infusion and given for 3 days.