Wednesday, December 1, 2010

Prostate Cancer: To Watch Or Not To Watch

If you knew that you had a cancer in your body, would you be willing to just "watch" it?  I think our gut reaction is to cut it out, irradiate it, take chemo, do something, anything.  Well a recent series of studies has been published that turns this thinking on its head.

In today's JAMA, the authors evaluated quality of life vs quantity of life.  More accurately, they assessed quality-adjusted life years (QALY) for active surveillance vs initial treatment in 65yo men with low-risk, clinically localized prostate cancer.  Compared to those who might have elected radical prostatectomy vs intensity-modulated radiation therapy vs brachytherapy, those choosing active surveillance enjoyed 11.07 QALY vs 10.23 QALY for surgery, 10.51 QALY for external beam radiation and 10.57 QALY for seed implants.  There was no mention of androgen deprivation therapy, which is typically offered for those with metastatic disease, and has recently drawn scrutiny due to its association with increased all-cause and cardiovascular mortality.

Before you go ballistic and toss virtual tomatoes at me, understand that the authors looked specifically at otherwise healthy 65yo men with localized low risk disease, eg PSA <10ng/mL, Gleason <6, and stage <T2a.  This calculation does not apply to either younger or older men or those with potentially more aggressive disease.

Well, we're pretty clear as to what's involved with surgery, external radiation & seed implants.  But what exactly is active surveillance?  In this model, the protocol consisted of physical examination, PSA measurement, and rebiopsy at 1yr after diagnosis and every 3yrs thereafter.  Active treatment/intervention with one of the other 3 options was performed at progression to Gleason score >7, other evidence of progression, eg PSA doubling time, or patient preference.

So who's crazy enough to watch & wait once a cancer has been diagnosed.  Well, consider the downside of treatment: impotence, eg erectile dysfunction, urinary difficulty, eg incontinence, and bowel problems, eg proctitis and incontinence.  For some men, the risk isn't worth the benefit.  But isn't this just a model?

Earlier this summer, a study of 6,849 men <70yo w/PSA <20ng/mL, Gleason <7 and stage T1-2 followed for 10yrs demonstrated 3.6% cancer-specific mortality in the surveillance group vs 2.7% in the curative intent group.  For those in the low risk group, cancer-specific mortality was 2.4% in the surveillance group vs 0.7% in the curative intent group.  More interesting was the other-cause mortality of 19.2% in the surveillance group vs 10.2% in the curative intent group.  In other words, the patients were 5-10x more likely to die with prostate cancer rather than from it.  So those authors deemed active surveillance a suitable option in this very narrowly defined population.

Last spring, authors followed 262 men <75yo w/PSA <10, Gleason <6 and stage T1-2a for 29mo and deemed active surveillance safe in this well defined group with low risk for clinical & systemic progression.

So is active surveillance for everyone?  Absolutely not!  But if you have the cojones to handle this and the psychological stress of waiting isn't going to give you an ulcer, then there appears to be plenty of evidence to support doing so.  In which case, you don't have to worry about erectile issues or incontinence.  After all, quality of life matters, not just quantity of life.  As always, it's a personal decision that must be made only upon review of all the information available with one's family & physicians.

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