Question: When is chemotherapy used in the treatment of prostate cancer, and do all prostate cancer patients receive the same type of chemotherapy?
Answer: Patients, in general, often associate the start of chemotherapy with a very grievous prognosis. In fact, most people seem to think that it's the beginning of the end, and nothing could be farther from the truth. In fact, we use chemotherapy very early on in patients who have very high risk of recurrence at the time of diagnosis. We use it before surgery. We've used it before radiation therapy, largely under the auspices of an investigational or clinical trial. However, one can use it after hormonal therapy fails or later on in the disease should there be a change in the biology of the cancer.
There are three major motivations for starting treatment. In most cases, patients go on to chemotherapy if they have failed the conventional treatment for prostate cancer, meaning hormonal therapy -- the attempt to remove testosterone from the circulation which feeds the cancer. When patients suddenly develop changes in their PSA, meaning the marker that we follow, with sudden rises with PSAs that are doubling less than six months or even less than three months, that is one of the indications for initiating treatment with chemotherapy.
Another indication is a patient who's just not thriving, someone who may or may not have metastatic disease -- that is, disease that has spread outside the confines of the prostate. These are patients who just may be lethargic; they have poor oral intake; they're not hungry and they just don't feel right. They may be suddenly a person who had been active and suddenly becomes bedridden. And we've found that chemotherapy can actually improve quality of life. Similarly, patients who may have failed other therapies, who have further progression of disease in bone which is causing symptoms, these patients may, in fact, require a fair amount of radiation to different sites, almost as if we were giving Band-Aids to different areas. And that's really what radiation does under certain circumstances.
However, because you can only give a certain amount of radiation to the bone marrow before you start suppressing the ability to continue to have normal blood cells made or blood elements made within the marrow itself, there is a need to try to spare the marrow from radiation. And we have found that giving chemotherapy not only palliates -- or improves pain -- but actually allows the blood counts to stay high enough so that additional treatments can be given. Overall, most patients will find that their quality of life is markedly improved when they start chemotherapy.