Chemoembolization is a treatment for unresectable cancer. It can reduce the size of cancerous tumors and in some cases improve the functionality of the liver. As with Radiofrequency Hyperthermic Tumor Ablation, chemoembolization it is not a cure, but a treatment for cancer.
Chemoembolization involves injecting a high concentration of chemotherapy directly to the liver via a catheter. The liver has two blood supplies; the hepatic artery and the portal vein. When a tumor forms in the liver, the liver takes all its blood supply from the hepatic artery, whereas a non-cancerous liver takes 75% of its blood supply from this artery and 25% from the portal vein. Chemoembolization is administered into the hepatic artery as this is where the tumor forms. Injecting this chemotherapy to the liver stops the blood flow and therefore deprives the tumor of oxygen which is needs to grow, causing the tumor to die. By administering the drug into this part of the liver it leaves the liver no choice but it take its blood supply from the portal vein which remains healthy as it has not been subject to the chemotherapy.
One of the benefits of Chemoembolization is it allows the chemotherapy to be applied directly to the liver without it spreading to the rest of the body. In effect Chemoembolization is targeting the cancer in two ways. The first is with the high concentration of chemotherapy injected to the liver and the second is by stopping the blood flow so the tumor has no oxygen to survive.
A sedative is used to relax the patient before the procedure, however the person generally stays awake for the duration of the procedure which takes 2-3 hours. Once administered, the chemotherapy begins work and starts to destroy the bad tissue and hopefully kills the tumor altogether. Numerous x-rays are taken to monitor the progress of the treatment. After the procedure there is some bleeding from the groin area and other side effects include nausea, vomiting and pain which can continue for up to 48 hours after the operation. CT scans are performed repeatedly after the operation to determine how much the tumor has shrunk; in cases where the treatment has not been successful the process is often repeated.
While this is a treatment and not a cure, around 70% of people achieve an improvement in their liver functionality after receiving chemoembolization.
Chemoprevention involves taking vitamins or agents in order to prevent cancer or to prevent or postpone the recurrence of the cancer. Chemoprevention also involves the person changing their diet to include or eliminate certain foods. Chemoprevention is a broad based treatment involving a range of agents and natural substances, many of which are still undergoing research and testing. Chemoprevention is not a cure for cancer, nor does it involve chemotherapy, it is a preventative measure used by high risk groups and people in remission.
The way chemoprevention is tested is through the use of clinical trials. Clinical trials are a way of gauging the effectiveness of new medical approaches. Both cancer sufferers and non-cancer sufferers participate in these trials to test the effectiveness of different substances, both natural and synthetic, in the prevention of cancer. Trials can include the use of one drug tested singularly or a combination of drugs. There are over 400 compounds currently being researched and tested to analyse their effectiveness in Chemoprevention.
There have been some positive results produced from some clinical trials in the United States with five agents showing promise as Chemopreventative compounds. These agents include selective estrogen receptor modulators (SERMS) including tamoxifen. Nonsteroidal anti-inflammatory drugs (NSAIDS) have also shown promise, as have calcium compounds, glucocorticoids and retinoids (chemical cousins of vitamin A).
The agents being tested in Chemoprevention deal with all types of cancer. To effectively determine which compounds are Chemoprevetative, thousands of people need to be tested over several years. There have been many trials in breast cancer research that have proven that women who take tamoxifen had 49 percent less chance of breast cancer. The drug finasteride is being tested to see if it prevents prostate cancer in men older than 55. Celecobix are being studied for the prevention of cancer in the esophagus and bladder while calcium compounds are being tested for the prevention of colon cancer. These are only a few of many compounds currently being studied in clinical trials.