Chemotherapy is the use of drugs to kill or slow the growth of cancer cells. These drugs are given by pill or injection.
Chemotherapy is very successful in fighting many types of cancer. However it is less effective in prostate cancer because prostate cancer cells do not grow as quickly.
In prostate cancer, chemotherapy may slow down tumour growth but it is not expected to destroy all cancer cells, therefore, chemotherapy is not recommended for men with early prostate cancer. Chemotherapy is most often given to patients with advanced stage prostate cancer who aren’t improving with hormone therapy.
Two courses of therapy are used in Canada: Mitoxantrone plus Prednisone Mitoxantrone is a chemotherapy drug. Prednisone is a steroid. This combination improves quality of life, but doesn’t lengthen it. There side effects of mitoxantrone are minor and prednisone improves mood, appetite and sense of well-being. This combination is only effective for a few months. Estramustine plus Etoposide Estramustine is a female hormone and a chemotherapy drug. Etoposide is a chemotherapy drug. This combination has strong side effects. Half the patients who use this combination have a lowered PSA level but patients show a PSA response, but it does not last. There is no proof that this drug combination improves survival rates.
A drug called docetaxel is approved in Canada for use in breast, lung and ovarian cancers. In the U.S. it has recently also been approved for use in hormone-refractory prostate cancer, in combination with prednisone. Studies show that docetaxel does not improve survival in men with hormone-resistant prostate cancer. Research is still being done to study the use of docetaxel in combination with other therapies for advanced prostate cancer.
Side effects vary depending on the type of drug, the amount used and the length of treatment. Most disappear when chemotherapy is stopped.