Bacillus Calmette-Guerin (BCG) is a drug that is used as a vaccine for tuberculosis, and is also used for the treatment of superficial bladder cancer. Scroll down to find out info on BCG treatment side effects, along with the effectiveness of this drug as a vaccine and as a bladder cancer treatment option.
Bacillus Calmette-Guerin is categorized amongst the biological response modifiers. BCG is mainly used for treating superficial bladder cancer. It is also used for providing immunity against tuberculosis, which is a medical condition that is caused by strains of Mycobacterium. The BCG drug contains the strain of weakened Mycobacterium bovis. The bacteria are weakened in order to lower the risks of reactions that could otherwise occur due to the injection of the bacteria. The side effects of the BCG treatment are mostly insignificant in comparison to its effectiveness as a cancer fighting drug. In this article, we will look into the effectiveness as well as side effects of BCG as a vaccine and as a bladder cancer treatment option.
When is BCG Administered in Tuberculosis Patients?
As mentioned earlier, BCG is also used for providing protection against a deadly disease called tuberculosis. It is generally administered to children who live in areas where a large number of cases of tuberculosis have been reported. Infants whose mothers have developed tuberculosis before, are also injected with BCG. Children who are traveling to areas where tuberculosis infections are quite prevalent, must also be vaccinated. However, there is a great need to ensure that pregnant women, or people who have tested positive for HIV or tuberculosis, must not be injected with this vaccine. Mantoux, which is a tuberculosis skin test, is conducted first, and BCG is injected into the skin, only when the test result is negative.
When is BCG Administered in Bladder Cancer Patients?
BCG treatment is also recommended for those who have been diagnosed with superficial bladder cancer. This is a type of cancer, which is restricted to the innermost lining of the bladder, and has not yet affected the bladder’s deeper muscular layer. Doctors may prescribe BCG treatment for bladder cancer if they feel that the risk of cancer spreading to the muscular layer is quite high. When used as a bladder cancer drug, BCG is not injected subcutaneously. It is introduced into the bladder through the process of intravesicular infusion. The drug flows into the bladder via a catheter. The catheter is clamped so that the drug remains in the bladder up to a period of time that is determined by the doctor. Doctors are not really sure about the mechanism of action of BCG, but administration of BCG is believed to be a form of biological therapy or immunotherapy.
It is believed that administering BCG may give rise to inflammation, which in turn, may trigger the production of immune cells that may destroy the cancerous cells. BCG is generally administered sometime after transurethral resection of the cancerous growth. The main objective of intravesical therapy is to destroy the cancerous cells that may still be present inside the bladder. The drug is not administered immediately after the surgery. Physical examination and diagnostic tests are performed prior to intravesical infusion. If the patient is suffering from urinary tract infection or any health problems, the administration of BCG will be postponed, until the infection clears completely. Though BCG treatment has certainly helped in preventing the recurrence or progression of cancer to an advanced stage, thereby lowering the need for bladder removal, certain BCG treatment side effects have also been reported.
Side Effects of BCG Treatment
Now that you have some idea about the uses of BCG, let’s move on to the side effects. Let me first tell you about the side effects that are associated with use of BCG as a vaccine followed by the side effects seen in patients with bladder cancer.
§ Side Effects of BCG Vaccine for Tuberculosis
Following BCG vaccination, it is normal to develop a red lump after a week. The lump appears at the place where BCG is injected. It turns into an open sore within a couple of weeks. Within a couple of months, the sore heals completely, leaving behind a scar at the site of injection. The side effects of BCG vaccine are rare, and are seen in cases where the vaccine has not been given in the correct manner. In such cases, one may develop an abscess at the injection site. Inflammation of the cervical lymph glands or glands located in the armpit may also occur. Though a small flat scar is left behind after a couple of months normally, in rare cases, there might be visible scarring. An allergic reaction is again rare, but if one does suffer from such a hypersensitivity reaction, one may experience facial swelling, hives or breathing difficulty.
§ Side Effects of BCG for Bladder Cancer
Let’s move on to the side effects of BCG treatment for bladder cancer. Since BCG is administered into the bladder, the side effects that one may experience are usually associated with the bladder. As mentioned earlier, BCG drug contains live weakened bacteria, that are believed to stimulate the immune system to target and destroy the cancerous cells. Though the incidence of a bacterial bladder infection or a urinary tract infection is not very high, at times, patients may develop a bladder infection after intravesical drug therapy. The drug may irritate the bladder, and cause mild side effects that may last for a couple of days. One may experience a frequent urge to urinate or may also feel a burning sensation while passing urine. In rare cases, one may even experience urinary incontinence, painful urination or see traces of blood in urine. Pain around the groin region, lethargy, fever, chills, malaise and flu-like symptoms, etc. could also be experienced by those who undergo BCG treatment for bladder cancer.
Side effects are usually mild, but one serious BCG treatment risk that is worth noting, is that of the patient developing a systemic BCG reaction. A systemic infection is an infection wherein the bacteria travel into the bloodstream. Such an infection may lead to sepsis, which in turn, may cause shock and affect the vital internal organs of the body. Such a reaction may develop anytime within a week of administration of BCG. It’s extremely essential that doctors take all necessary precautionary measures to prevent any trauma to the urinary tract while administering the drug. Aseptic surgical instruments or techniques must be used to prevent contaminants from entering into the urinary tract. Complications that may arise in male patients due to the administration of BCG include inflammation of testes, epididymis or the prostate gland. Conditions such as swollen lymph nodes, hepatitis, pneumonitis or respiratory distress could also occur as a result of systemic infection. These can pose serious health risks, and must be treated immediately. Doctors may follow a symptomatic approach while treating hypersensitivity reactions. The patient may need oxygen supplementation if he/she suffers from shortness of breath. Antibiotics would be required in order to treat the bacterial infection and steroids may be prescribed to lower the inflammation.
BCG treatment has certainly helped people who have been diagnosed with superficial bladder cancer. The intravesical administration of BCG is performed once every week for about six weeks. Though BCG treatment success rate is quite high, and it has proved to be helpful in preventing the recurrence of cancer, one must watch out for complications. BCG vaccine has also helped in the prevention of tuberculosis to a great extent. However, there is a need to ensure that medical help is sought, if one develops an allergic reaction to BCG.