More on RP vs. "watchful waiting"

[dentaltwin]

The Scandinavian Prostate Cancer Group Study Number 4 (SPCG-4) shows a survival benefit for RP in localized PC, but the length of the study plus the changes in detection, surveillance and treatment through the years suggests there may be less here than meets the eye. Discussion here:

medpagetoday.com/urology/pr...

[Tall_Allen]

Yeah - the problem is we all want long-term studies but by the time we get the results they are often irrelevant. I discussed the problem in this article:

pcnrv.blogspot.com/2016/08/...

[dentaltwin in reply to Tall_Allen]

Nice review. So many potential confounders here. It certainly doesn't make decision making easy. And even then, as you say, "they never predict for the individual case that we really want to know about; i.e., 'me'"--always a problem when trying to apply population-based data to individuals.

Thanks for posting.

[ASAdvocate]

That study is worthless. Watchful waiting is for older men with significant co-morbidities and a short life expectancy. What value is a 20 year study?

On the other hand, when active surveillance is measured against immediate surgery, there is no significant increase in PCa mortality if the AS men later needed treatment.

[dentaltwin in reply to ASAdvocate]

If we had a trial of sufficient size with definitive parameters of case selection, I would love to see that--and if I could get 20 years out I would take it.

[ASAdvocate in reply to dentaltwin]

There already are 15 and 20 year studies on surgery versus active surveillance. They involve the AS programs at Johns Hopkins and at Sunnybrook. They show that there is no increased mortality between men who started AS and later needed treatment, versus men who had immediate surgery.

But, AS is a very different protocol than the "do nothing" regimen used in this study.

[dentaltwin in reply to ASAdvocate]

The referenced paper in NEJM is behind a pay wall, and though the abstract references "watchful waiting" it's not clear to me that this group did "nothing", although certainly selection and management of AS has changed over time.

If you have 20 year studies of active surveillance I'd like to see them.

Incidentally, JAMA published a paper in the past week suggesting that risk assessment in black men has been the subject of debate--possibly influencing selection criteria for AS:

jamanetwork.com/journals/ja...

[ASAdvocate in reply to dentaltwin]

Here you go:

cancernetwork.com/oncology-...

[dentaltwin in reply to ASAdvocate]

Thanks. Perhaps there are some biostatistics mavens out there who can explain this (I've seen similar numbers from other sources):

"According to the American Cancer Society, in 2016 an estimated 180,890 new cases of prostate cancer were diagnosed in the United States, making this disease the most common solid tumor in men.[1] Despite the high incidence, only 26,120 men are estimated to have died of prostate cancer in 2016; the 10-year and 15-year relative survival rates for prostate cancer are 98% and 95%, respectively.[1] ".

Question is, if the number of fatalities appears to be about 14% of the number of diagnoses, how do they quote 10-year PC-specific survival of 95%?

I suspect this may involve the changing diagnostic landscape, in which many of those dying now may have been diagnosed before widespread use of PSA, in which case there would have been a relatively higher proportion of advanced cases at diagnosis historically. Any other ideas?

[MelbourneDavid in reply to dentaltwin]

A direct conclusion from that data is that most men, who were diagnosed recently who die of prostate cancer will die 15+ years after diagnosis. That's also what the prostate cancer screening studies show. It is also true that current treatments are effective for most men diagnosed early. There are the unfortunate men who have highly aggressive prostate cancers or late diagnosed ones that kill in a few years.

[dentaltwin in reply to MelbourneDavid]

Of course most men with prostate cancer die of other causes. I can't say I've seen any literature about how long after diagnosis most PC-specific deaths occur. I also realize that introduction of PSA has greatly skewed that interval between diagnosis and death.

Your reading, that 10 or 15-year cause-specific deaths don't jibe with total cause-specific death makes sense, though I haven't found literature specific to deaths that far out on the time line.

[dentaltwin in reply to MelbourneDavid]

I don't have time for this now. ;-). The first paper I see (from 2011) claims that "Approximately half of the men who receive a diagnosis of prostate cancer (PC) die from PC itself"(!)--an assertion that is refuted in the same paper.

ncbi.nlm.nih.gov/pmc/articl...

Obviously the numbers are all over the place; I think that the safest course is to try not to cherry-pick studies via confirmation bias--the statistics are in flux. I have some sympathy for surgeons and radiation oncologists who have to give advice to patients based on a rapidly-changing knowledge base.

[David1958]

Wouldn't it be interesting to poll all the members of this forum to create a psuedo study? I see we have 1340 members, which is kind of small, but might be worthwile anyway. We could ask the age you where diagnosed, whether you had treatment or decided AS. If treatment was selected, what was the outcome? If AS was selected, what was the outcome (so far). I was 52 when diagnosed, PSA 5, Gleason (3+4)7, and selected RP within 2 months of diagnosis. No radiation follow up. PSA undectable for 7 years so far.