Prostate cancer treatments – new developments

Prostate cancer treatments – new developments

Prostate cancer treatment is one of the success stories in medicine today. Many prostate cancers tend to be slow growing and a range of treatments is available at different stages. This means that the outlook for a man diagnosed with prostate cancer is very good – his chances of surviving for 5 years are virtually 100% and just over 90% of men survive for a decade. Around 75% can expect to still be enjoying life 15 years on, thanks to continual advances in prostate cancer treatment.

These survival statistics are not any reason to be complacent, however. This disease still kills 200,000 men every year in Europe and the USA. New prostate cancer treatment strategies, new drugs, and new drug targets are still being actively sought and developed.

This article on prostate cancer is by Kathryn Senior, a freelance journalist who writes health, medical, biological, and pharmaceutical articles for national and international journals, newsletters and web sites.

Treatment for early stage tumours

In its early stages, prostate cancer treatment tends to be quite cautious. Tumours in the prostate are often slow growing and pose no threat to health and produce no symptoms. Invasive treatments cause more problems than they solve, so there is a period of ‘watchful waiting’ with regular checkups. These involve measuring the level of the prostate specific antigen (PSA) in the blood – if this starts to rise, then prostate cancer treatment changes tack.

• Surgical prostate cancer treatment: Many men start off with surgery to remove the tumour and often then prostate gland itself. New developments in this area of prostate cancer treatment include laparoscopic surgery. This is carried out to minimise the size of the incision used and to improve recovery times.
• Radiotherapy: This is used to shrink the original tumour and to discourage it from spreading outside the prostate. Radiotherapy can either be done with an external beam, using a three-dimensional approach, or it can be internal. The most recent development in this type of prostate cancer treatment involves implanting tiny seeds containing radioactive particles. When these are placed directly in the prostate, the effect can be very localised and very specific.

Blocking hormones

Surgery or radiotherapy is often followed up by hormone-blocking prostate cancer treatment. Prostate cancers grow much faster in the presence of the male sex hormone testosterone, so cutting off the supply of this hormone is very effective. In the past, this was achieved by removing the testicles but today it is more likely to be given drugs to reduce the activity of testosterone to almost zero. Anti-androgens block the activity of progesterone, preventing it binding to cancer cells while pituitary down regulators block the production of testosterone by acting on the brain.

There are different approaches to using hormone-blocking drugs in prostate cancer treatment, depending on the stage of the prostate cancer:

• Combination prostate cancer treatment: Anti-androgens or pituitary blockers are used in conjunction with either surgery, radiotherapy or both if your specialist thinks that there is a risk of the cancer coming back after the prostate has been removed or after the tumour has been shrunk.
• Hormone blocking prostate cancer treatment only: Anti-androgens and pituitary down regulators can also be used alone – this is more likely to happen if your cancer has started to spread out of the prostate gland and is more difficult to treat with either radiotherapy or surgery.

In either case, the hormone-blocking drugs can be given continually, sometimes for a period of years, or intermittently. You have this kind of prostate cancer treatment for a few months, and then have a break before restarting. Clinical trials have now shown that both strategies are equally effective – it comes down to a decision made by your doctor and you depending on your circumstances.

Advanced treatments

Using a combination of surgery, radiotherapy and hormone blocking prostate cancer treatments usually keeps prostate cancer in check for many years. PSA levels are still monitored regularly and in some men, this rises despite active hormone blocking treatment. This is a sign that the prostate cancer has advanced and moved out of the prostate, commonly forming metastases in bones and in the soft tissues in the abdomen. More aggressive prostate cancer treatment is then necessary.

The chemotherapy drug docetaxel was the first to be approved for used in advanced prostate cancer after clinical trials completed in 2004 showed it improved survival. In the late spring of 2010, another chemotherapy drug, carbazitaxel was approved as a follow up prostate cancer treatment in men who don’t respond to docetaxel.

Treatments in development

Since men with advanced prostate cancer are at the highest risk of death, this area is the focus of a great deal of prostate cancer treatment research. Many of the biochemical pathways in prostate cancer cells have now been described and new drugs targeting their components are now in the latest stage of clinical trials. Some could be approved and made available over the next two or three years. These include drugs like abiraterone and provenge, which are better hormone blockers, and drugs that block the endothelin-1 pathway, which may help prevent bone metastases from becoming established.

Researchers are hopeful as many of these drugs are showing good results in phase III clinical trials and do not have as many side effects as chemotherapy-based prostate cancer treatments.