A number of factors complicate the decision to use cytotoxic chemotherapy in men with advanced prostate cancer. Among these factors are complicating illnesses which may occur in this population of older men, reduced functional capabilities which may occur in men with advanced prostate cancer and the long-standing belief that "chemotherapy" has no role in the management of prostate cancer.
Before considering the details of the use of chemotherapy, it is important to briefly review what is meant by chemotherapy. One approach is to classify as chemotherapy all treatments that go throughout a man's whole body following initial androgen deprivation. These are easily classified as hormonal agents and include:
The more standard definition of chemotherapy is an agent which poisons the cells’ growth and reproductive machinery. It includes drugs such as:
These agents are drugs which have encouraging antitumor effects in men with advanced prostate cancer.
While a number of new combinations of chemotherapy drugs offer potential, perhaps the most important point to emphasize in considering chemotherapy for prostate cancer is that there are now two carefully conducted, randomized trials in which men with advanced prostate cancer, progressing despite androgen deprivation, received mitoxantrone plus a glucocorticoid or the same dose of glucocorticoid alone. In each of these trials, symptomatic improvement, reduced use of pain medication and substantial PSA reduction were statistically more likely to occur in the group of men who received mitoxantrone.
Mitoxantrone is an agent which is intravenously administered once every three weeks. Primary side effects are a very small frequency of hair loss and mild reduction in white blood cell count, which is rarely associated with any symptoms or complications. Prolonged or very high-dose mitoxantrone is associated with the potential for damage to the heart muscle. Mitoxantrone is extremely well-tolerated and clearly offers symptomatic improvement in many men with advanced prostate cancer. Unfortunately, it is still the minority of men who benefit from mitoxantrone therapy and improved agents are vitally needed.
A number of very interesting new combinations are being developed which appear to cause substantial PSA declines in more than 50 percent of men, as well as symptomatic improvement in men with advanced disease. The three combinations being explored most actively are docetaxel, docetaxel + estramustine and doxirubicin + ketoconazole alternating with vinblastine + estramustine. While considerable work remains to be done in developing truly effective chemotherapy for prostate cancer, well-tolerated drugs are available which clearly can improve symptoms and quality of life in men with advanced prostate cancer.
The Prostate Cancer pages of this Web site are part of the Comprehensive Prostate Cancer Awareness Program (CPCAP), a major regional effort to reduce the rates of death and illness caused by prostate cancer in southwestern Pennsylvania. Funding for CPCAP is provided by a grant from the Commonwealth of Pennsylvania.
