Prostate cancer is the commonest cancer in Australia.
In most men, when the cancer is first found it is confined to the prostate and usually can be cured with surgery or radiotherapy. Sometimes certain types of prostate cancer do not even need immediate treatment but instead can be watched carefully and treated only if necessary. Unfortunately, in some men the cancer cells have already spread and can be found elsewhere in the body at the time the cancer is first found, or show up elsewhere some time later. At the moment it is not possible to cure these cancers that have spread, but there are effective treatments available that can stop the cancer growing, shrink it down, and keep it that way often for long periods of time – even years in some cases. These treatments involve lowering blood levels of male sex hormones like testosterone, which the cancers use to survive and grow. Reduction of these hormones to low levels is like turning the gas down under the kettle: the cancer goes “off the boil” but does not disappear completely.
Sometimes the cancer will grow again at a later point in time and again there are good treatments available that can help control the cancer then. More treatments are coming through as research and clinical trials provide information about ways of treating these cancers more effectively. One approach that is often used in that setting is chemotherapy using a drug called docetaxel. Clinical trials have shown that when docetaxel is used in these more advanced cancers, it can often shrink the cancer, improve symptoms that the cancer might be causing, and on average men treated in this way live longer than those who do not have chemotherapy. If this is your situation then it is worth talking about these things with your treating doctor.
Some exciting new information has now become available. The results of a clinical trial were presented at a major cancer meeting in Chicago in June 2014. This trial did something different. It used chemotherapy in men with prostate cancer that had been found elsewhere in the body, but the difference was that the chemotherapy was started much earlier: at the time the men first started their hormone treatment. The clinical trial compared men who were given the current best standard treatment (hormone treatment, known to be very effective) with another group of men who were given that same treatment as well as docetaxel chemotherapy.
The results of the trial showed that adding chemotherapy was safe and was well tolerated by the vast majority of men on the trial. Significant side effects were very rarely seen. Most importantly, the group that received chemotherapy at the same time the hormone treatments started had a much better chance of surviving longer, living on average about 13 months longer than the other group. Another way of looking at this information is to say that the group of men who received the chemotherapy as well as the hormone treatment had about a 40% less chance of dying at any given moment than the men who received hormone treatment alone, even after the chemotherapy was finished. This effect of chemotherapy is much bigger than when it is used later in the course of treatment of the cancer, as we have been doing until now.
What does this mean for you or your loved one with prostate cancer?
It depends on what the cancer is doing and where you are up to in your treatment. You need to discuss these questions with your treating doctor and cancer specialist. In each of the following situations maybe there is also the option of taking part in a clinical trial yourself.
- If your cancer is confined only to the prostate: these results don’t apply to you. You should talk to your doctor about what treatment is needed for the cancer in the prostate. It is possible that it might not need any treatment at all right now but you should consider all your options. There is no evidence at all that chemotherapy helps in this situation.
- If your cancer seems to have come back because the PSA test is detectable again, but nothing is showing up on the scans anywhere else: these results don’t apply to you. The trial only gives us information about cancers that are detectable elsewhere in the body on scans. There is no evidence at all that chemotherapy helps in this situation.
- If your cancer has spread elsewhere and you have already had hormone or other treatment for it: these results don’t apply to you. You should talk to your doctor about what options there are, and adding chemotherapy might be one thing to consider.
- If your cancer has spread elsewhere but you have not had any hormone or other treatment for that yet: these results might apply to you. You should talk to your cancer specialist about it and see whether the idea of adding chemotherapy to your hormone treatment is something you should consider.
Remember as well: these sorts of advances in our understanding of cancer and improvements in outcomes are only possible because people have decided to take part in clinical trials. We are so grateful to the men who took part in this trial, because they have generated the evidence that now allows us to talk sensibly to you about this. A suitable trial might not always be available to you, but if it is, remember that you will always receive the best possible care when you go on a clinical trial; no-one ever knowingly is given less than the best known treatment. It’s not always the case that the new treatment is better either. But think about adding this question to the list you have for your doctor: is there a clinical trial that might be suitable for me?
Disclaimer: I do clinical trials through ANZUP Cancer Trials Group. I don’t get paid for this; I do them because they need to be done and because it’s the only way we make any progress in cancer or other disease. More information about clinical trials in prostate cancer and other cancer types can be found here: www.anzup.org.au.