By Peter Orengo
Nairobi, Kenya: Researchers say they have identified a sub-group of cells that could contribute to prostate cancer recurrence, opening up new ways to treat the disease, which has emerged as a top killer of men over 40 in Kenya.
Published in Science Translational Medicine, a study led by Monash University researchers in Australia, found prostate cancer cells that survive androgen (male sex hormone) withdrawal treatment — one of the main treatments for prostate cancer.
Previously unidentified, these cells are potential targets for future treatments. As they are present early in disease development, there is the possibility of therapy before the cancer reaches the aggressive, incurable stage.
Prostate cancer is the most common form of cancer in men, affecting one in six men in Kenya. A non-smoking man is more likely to develop prostate cancer than he is to develop colon, bladder, melanoma, lymphoma and kidney cancers combined.
In fact, a man is 35 per cent more likely to be diagnosed with prostate cancer than a woman is to be diagnosed with breast cancer.
Any man can get prostate cancer but it is more common amongst men above the age of 50 years. The risk increases, as one gets older. Studies have shown that close to 50 per cent of men over the age of 75 have prostate cancer.
For advanced cases, the best available treatment involves drugs that effectively mimic castration and so deprive the tumour of the male hormones that causes it to grow.
Androgen deprivation therapy is highly effective; however, the tumour eventually becomes resistant to the treatment and regrows in an incurable form.
Led by Prof Gail Risbridger and Dr Renea Taylor of Monash University, researchers obtained tumour samples from 12 men with early stage, localised prostate cancer.
Then, using mouse models to mimic the progression in humans, they closely observed how the cancer cells responded to and survived androgen deprivation therapy. Even after several weeks of androgen deprivation, residual tumour cells continued to persist.
“The results indicate that these persistent cancer cells somehow differ from cancer cells that respond to androgen withdrawal, and are likely to be the precursor cells that lead to advanced androgen-resistant disease. We will now investigate how to effectively target these cells,” Prof Risbridger said.
Prof Mark Frydenberg of the Monash Department of Surgery, and Chairman of the Department of Urology, Monash Health, said ultimately the findings could lead to additional therapies to increase the effectiveness of existing prostate cancer treatments.
The research also appears in the Science Daily and was supported by the National Health and Medical Research Council of Australia, the Victorian Cancer Agency and the Prostate Cancer Foundation of Australia.