We're only 12 months into our 10-year strategy to tame prostate cancer, but that doesn't mean we haven't already made exciting progress in diagnosing, treating and preventing the most common cancer in men. Our resident expert, Dr Ian Le Guillou, gives us his top ten biggest research breakthroughs (in no particular order) from 2016.
In June, researchers announced results of a trial to see if MRI imaging could reduce the need for biopsies in diagnosing prostate cancer. Biopsies are painful and can lead to serious infections, so finding a way to reduce their use is really important. We’re still waiting for the full results but it seems that a sophisticated type of MRI is good at ruling out cancer, meaning fewer men will need to have biopsies.
Almost half of prostate cancers are driven by a mutation in a gene called PTEN, which makes them tend to be more aggressive. Researchers from the London Movember Centre of Excellence showed that they could identify which men had this mutation and that an experimental drug could slow the growth of the cancer. This still needs to be tested in more men and for a longer time, but it shows what a difference it could make to get the right treatment for each man.
Men with low-risk prostate cancer can be offered active surveillance, surgery or radiotherapy – but which is the right choice? Active surveillance offers the potential to avoid or delay the side effects from the other treatments, but many men worry that it could leave them at risk of their cancer spreading. The ProtecT trial randomly assigned each of the three treatments to 1,600 men and followed their health for the next ten years. They found there was no real difference to the ten-year survival rate between the options, which should give men greater confidence in active surveillance.
A standard treatment for radiotherapy requires 37 doses – that’s 37 trips to the hospital over seven-and-a-half weeks. That’s difficult for the man, their family and the hospital. So researchers at the Royal Marsden wanted to see if giving a higher dose in each burst could mean fewer trips. They found that you could have just as good treatment in only 20 doses – almost half the time.
Researchers at the London Movember Centre of Excellence discovered that inherited DNA mutations raise the risk of more aggressive forms of cancer. Men with these mutations are more likely to do better on certain types of treatment, so this shows the importance of genetic testing for men with advanced prostate cancer.
Research funded by us found a potential new drug that can kill cancer cells when combined with hormone therapy. The drug targets ‘hypoxic’ cells in tumours, which means that they’ve adapted to survive with little oxygen. These cancer cells can trigger a relapse as they aren’t as strongly affected by hormone therapy. By combining treatments, we could have a way to destroy these resistant cells for the first time – but it still needs to be tested in men first.
A new type of drug that is activated by a laser could offer a way to target just the cancerous region in the prostate. A trial of over 400 men tested this focal therapy, which reduced the need for surgery or radiotherapy compared to men on active surveillance. But we now need to see which men this type of therapy is most appropriate for.
Hormone therapy (or androgen deprivation therapy) is a common treatment for prostate cancer by reducing the amount of testosterone in the body. This is because testosterone is thought to drive the cancer’s growth. Researchers funded by us found that testosterone leads to changes in the surface of the cancer cells, making them more likely to survive treatment and spread through the body. There are treatments for other diseases, such as breast cancer, that already target this behaviour so they could potentially also work for men with prostate cancer.
Prostate cancer cells eventually become resistant to low levels of testosterone, but this can leave them vulnerable in other ways. A small trial of 47 men tested the idea that this could make the cancer sensitive to high amounts of testosterone. By switching back and forth between floods and droughts of the hormone, the cancer is constantly kept on its toes and could stop it from becoming resistant.
Drugs that trigger the body’s immune system to fight cancer have been successful in melanoma, but they’ve been largely disappointing for prostate cancer. This year, we saw the first results from a trial of a melanoma drug in men whose advanced cancer was resistant to enzalutamide. It was only a small trial of 28 men, but two-fifths of them had the same or lower PSA level after treatment. This is impressive for men at a stage where the cancer is incurable, however it clearly doesn’t work for everyone.