Death rates from metastatic prostate cancer have remained "mostly unchanged over the past 25 years," a study of 19,336 men with an advanced form of the urological disease has found.
Publishing their findings online in the journal Cancer, the researchers from the University of California, Sacramento, had been expecting improvements in these mortality rates.
The cancer experts from the Davis Medical Center had hypothesized that a better rate of survival from advanced cancer would have explained the improved overall survival that has been observed across all men with different stages of prostate cancer.
But the authors "did not find any survival gains for men with advanced cancer."
Dr. Marc Dall'Era, urologic oncologist and senior study author, says the findings add to the body of evidence about detecting prostate cancer through PSA (prostate-specific antigen) testing.
"The effect we're seeing on mortality in this group is more that we've shifted the stage of diagnosis much earlier," Dr. Dall'Era says, adding:
"In other words, because the PSA test detects cancer earlier, fewer men go on to be diagnosed with metastatic disease.
However, there has been no survival improvement for men with metastatic disease to account for the overall mortality decline among all men with prostate cancer."
The results highlight the "urgent need to develop better treatments" for men with metastatic prostate cancer, the UC prostate cancer specialists say.
Co-author Dr. Ralph de Vere White, director of the UC Davis Comprehensive Cancer Center, says:
"This is a landmark paper because it highlights, in an indisputable way, the problem we face."
"Though we can reduce prostate cancer mortality," he adds, "we have failed to reduce mortality among those with metastatic disease - the advanced prostate cancer that ultimately kills these men."
Study adds to the controversy over PSA screening
The evidence for or against the value of routinely testing PSA levels in men, as a means of early prostate cancer detection, has been evolving for a number of years and remains controversial.
Dr. Dall'Era says of the new data:
"This finding suggests that routine PSA testing, which has dramatically reduced the incidence of metastatic disease, may be effective in reducing mortality from the disease, as well."
But while such a view based on the new evidence supports routine screening, this research will play only partly into a future consensus view - and presently, guidelines in force do not back routine PSA tests.
Dr. H. Ballentine Carter, professor of urology at Johns Hopkins Medicine, chaired a panel that developed a new clinical guideline in May 2013 for PSA testing.
"It's time to reflect on how we screen men for prostate cancer and take a more selective approach in order to maximize benefit and minimize harms."
The guideline from the American Urological Association (AUA) was an update on its position on PSA screening in men, future versions of which will be further informed by the present "landmark" study and other ongoing research.
The AUA guidance does not recommend routine screening in any age groups below 55 years and points to the test's controversy by saying it is a matter of discussion as to whether there is worthwhile benefit for those aged between 55 and 69 years.
The recommendations add:
- "To reduce the harms of screening, a routine screening interval of 2 years or more may be preferred over annual screening in those men who have participated in shared decision-making and decided on screening.
- As compared to annual screening, it is expected that screening intervals of 2 years preserve the majority of the benefits and reduce over diagnosis and false positives.
- Routine PSA screening is not recommended in men over age 70 or any man with less than a 10-15 year life expectancy."
Another controversy in prostate cancer centers on the treatment choice between aggressive surgical removal or a more conservative watch-and-wait approach.
Medical News Today published news in August 2013 that research 'backed watchful waiting' in prostate cancer. Here is a further pair of recent headlines in prostate cancer news: