Hi Leeway,
Your doctor would need to determine if cytoreduction surgery is necessary and that decision is usually a result of tumor size, location and growth rate. If the tumor size and spready is small, and limited to the inner lining of the bladder, then hyperthermic chemotherapy could be applied using a Foley catheter. In such a case, the advantage of hyperthermic chemotherapy over systemic chemotherapy is that the drug concentration can be increased by orders of magnitude (20 - 500), depending upon the drug used. This higher concentration increases the drug penetration depth within the tumor. As to the question of why hyperthermia is needed, a more lengthy response is needed.
I have recently been in contact with Dr. Mark Dewhirst who heads Duke University's Hyperthermia Treatment Program (
http://hyperthermia.mc.duke.edu/overview.htm). He provided some direction and primer information with regards to the effects of hyperthermia on tumors by itself and as part of some other procedures.
In general, a cancer is simply normal tissue with damaged DNA that causes it to divide uncontrollably. As a cancer grows it quickly outstrips its blood supply, leaving tumors oxygen/blood starved and resistant to radiation and chemotherapy. This state if blood and oxygen shortage is known as hypoxia. Unfortunately, when tumors are hypoxic it makes them harder to treat because chemotherapy requires adequate blood flow to carry the drug into the tumor and radiation therapy must produce oxygen radicals to destroy cancer cells. Most importantly, hypoxic tumors are also very dangerous because they are believed to create conditions that cause cancer to spread, and to worsen the cancer by eliminating all but the most aggressive cancer cells in the tumor (i.e. those cancer cells that can survive hypoxic conditions).
There are several explanations for why hyperthermia increases the effectiveness of cancer therapy dramatically. As the body’s natural response to heat, hyperthermia increases blood flow and oxygenation, particularly in non-hypoxic regions of tumors, overcoming tumor resistance to radiation and chemotherapy. Hyperthermia also improves the performance of certain cancer drugs. Hyperthermia further assists by destroying cancer cells during especially resistant phases of cell division. In addition, hyperthermia induces heat-shock proteins to the blood stream, which provide a danger signal to the immune system. This danger signal, recognized by natural-killer cells, can awaken the immune system to fight back.
Hyperthermia destroys cancer cells similar to the way the body uses fever to fight off other forms of disease. Since your body dissipates heat by increased blood circulation, cancerous tumors with sluggish or irregular blood flow leaves them vulnerable to destruction at elevated temperatures. The surrounding healthy tissues are safe because they have normal, efficient blood vessel systems. Scientists attribute the destruction of cancer cells at hyperthermic temperatures to damage in the plasma membrane, the cytoskeleton and the cell nucleus. Hyperthermia also kills cancer cells through nutrition starvation, and through increased acidity in cancer cells unable to return waste created by anaerobic metabolism, disrupting the stability of cellular proteins.
Below is a link to a Hyperthermia Fact Sheet published by the National Cancer Institure.
http://www.cancer.gov/cancertopics/factsheet/Therapy/hyperthermia
Dilber MC Theme by HarzeM
