The survival rate for advanced prostate cancer is high when detected early and contained within the prostate, but for men with cancer that has spread and is growing rapidly, the outlook isn’t so great. Men with tumors lacking a gene called PTEN have a particularly poor prognosis.
However, a recent study combining two drugs – abiraterone, which stops the production of testosterone, and an experimental drug called ipatasertib – showed promising results in slowing down the growth and progression of cancer. Doctors hope this combination will work to extend the lives of patients and allow them to spend more quality time with loved ones.
Lead study author Johann de Bono, MB CHB, PhD, MSC, professor of Experimental Cancer Medicine at The Institute of Cancer Research, London, and Consultant Medical Oncologist at The Royal Marsden NHS Foundation Trust, stated in a press release:
“We have shown that combining an existing and a new drug to attack cancer on two different fronts can keep men with prostate cancer healthier for longer. The findings offer a promising new treatment option for patients with a common and aggressive type of prostate cancer and could eventually change clinical practice for these men. PTEN is one of the most commonly deleted genes in prostate cancer, so this study offers hope to many patients.”
What does the PTEN gene do, and how does the new treatment help?
According to information from the U.S. Library of Medicine, the PTEN gene gives the body instructions for producing an enzyme found in most tissues. This enzyme keeps cells from growing and dividing too rapidly or uncontrollably, which helps in preventing cancer from spreading quickly. Around half of men with advanced prostate cancer have tumors with faulty PTEN genes.
In most men, prostate cancer cells can’t grow without the male hormone testosterone, and the drug abiraterone is known to be effective at blocking signals that produce that hormone. Cancers that lack a functioning PTEN gene tend to flock to AKT, a protein involved in transferring growth and survival signals inside cancer cells. The drug ipatasertib blocks these signals to prevent the rapid progression of cancer. By combining abiraterone and ipatasertib, researchers are simultaneously switching off two powerful growth signals that fuel prostate cancer.
Trial results bring hope to men with advanced prostate cancer
In a trial funded by Roche, a team of researchers led by The Institute of Cancer Research, London, along with The Royal Marsden NHS Foundation Trust, discovered that giving abiraterone along with ipatasertib reduced cancer progression in men whose tumors lacked PTEN by 23%, compared to those who only took abiraterone. Six percent taking abiraterone alone went into remission, but of those taking the combination, 19% showed no evidence of disease. The study took place in 26 countries and involved 1,101 men (521 of whom had tumors without a fully functioning PTEN gene). The results were published in The Lancet medical journal.
While initial results of the study are encouraging, more research needs to be done to determine overall survival benefits. Seasons will continue to watch for updates on advancements in prostate cancer treatments.