Small Study, Big Results
Last week the journal Urology put out a statement that suggests, according to a new pilot study, some men who have previously been considered incurable can now possibly be cured.
Results from the pilot study showed an aggressive combination of treatments have been shown to eliminate detectable disease in selected men with metastic spread. However, the authors of the study say longer and larger studies are needed to assess the durability of the results.
The authors of the pilot study chose two novel measure to determine a disease-free state after treatment had concluded: an undetectable PSA plus a return of testosterone production.
Treatments for those in the study included hormone therapy, radical surgery to remove the prostate and where necessary the nodes, and radiotherapy to take out the spots in the bone.
Currently removing the prostate and nodes in men whose cancer has already spread is controversial and has undesirable side effects, but the authors say it is part of their aggressive treatment strategy because there is evidence it helps.
The Pilot Study
Study participants started on hormone therapy but ceased when they had responded. The goal was to eliminate all detectable disease at 20 months in men who had recovered their testosterone.
Four of the men with bone spots made it. One went an extra five months, one an extra six and one an extra 27. The fourth man made an extra 46 months – meaning signs of his cancer returned 5½ years later.
The authors say this could not have been achieved with any single therapy alone, and note that 19 of the 20 men achieved an undetectable PSA with combined treatment but in many, testosterone and PSA levels began to rise once the effects of hormone therapy began to wear off.
While the study team led by Howard Scher, chief of the Genitourinary Oncology Service at Memorial, included a distinguished list of high-hitting practitioners, some commentators questioned why it was published in one of the lower-ranked journals in the field.
In Australia, the response has been mixed.
“It’s a bold claim for a small, single-centre pilot study, especially as we know that men with no detectable prostate cancer can suffer recurrence many years after treatment,” says Associate Professor Anthony Lowe, of the Prostate Cancer Foundation of Australia.
For Professor Jeremy Millar, director of Radiation Oncology at Alfred Health in Melbourne, the study shows that with aggressive therapy the cancer can be “controlled”, not that it can be cured.
He says the concept, however, of treating early metastatic disease is exciting.
“The Sloan Kettering doctors are to be commended for their hopeful vision and their methodical work; but we are many years away from proof that this potentially costly, aggressive and potentially harmful combination makes any long-term difference to men with this distressing problem,” he says.
“The doctors are taking the correct approach to building the evidence and we should pay attention to work like this with an appropriate optimistic scepticism in the hope they might be on the right track.”
While this pilot provides proof of concept for early metastatic prostate cancer with acceptable morbidity in 20 men, it should not be considered as standard of care.
The study will likely stimulate further research and is an incremental step towards improving the survival rate and lives of men with this cancer.