Research to Focus on Role of Immune System; Dr Lee Campbell Explains How Cancer Research Wales Is Funding Some Vital Research into Prostate Cancer

Article excerpt

Byline: Lee Campbell

PROSTATE cancer is the most common form of cancer among men in Wales.

In the majority of cases, long-term control of the disease is easily achieved through radiotherapy, hormone therapy and surgery. Unfortunately, after treatment, about 20% to 30% of patients will eventually relapse and develop secondary cancers.

It is for these patients, and those who already had secondary disease at the point of diagnosis, where treatment can be more challenging.

Much of the work Cancer Research Wales is funding into prostate cancer focuses on the role of the immune system, as it is the common hallmark of most malignant cancers.

It was recently discovered that the immune system of cancer patients tends to be suppressed - either generally, or in the area surrounding the tumour. It is this suppression that allows the cancer to grow and spread, unrestrained by the army of special immune cells which usually act as "guardians" to keep us free from disease by destroying malignant cells in the body.

Immune-based treatments, in the form of cancer vaccines, are quickly becoming possible for patients where prostate cancer has spread. Several high-profile clinical trials have shown that immunotherapy can prolong survival in some prostate cancer patients.

However, some questions have arisen from these trials. The effectiveness of any vaccine depends on the immune system's ability to mount a sufficient antibody response against the "foreign" molecules found on cancerous cells.

In prostate cancer patients with impaired immune systems, this effective response may be compromised. Also, for the vaccine to have its maximum effect, the correct timing and scheduling of their use in the patient's treatment pathway appears to be an important factor.

Cancer Research Wales scientists are beginning to provide vital and muchneeded insights into the processes that control immune responses in prostate cancer.

The team, based at the Cancer Research Wales laboratories in the grounds of the Velindre Cancer Centre, in Cardiff, have discovered that prostate tumours are capable of releasing microscopic particles - known as exosomes - which causes some of the immune suppression. …