PROSTATE CANCER WATCHFUL WAITING

COMMENTARY ON TEMPORARILY DEFERRED THERAPY PAPER

I was recently directed to a study on Watchful Waiting as an option for 'younger' men - men under the age of 70 years. The study was undertaken because most of the studies available for Watchful Waiting were done using pre-PSA data and this meant that the men were older, and the PCa was often more advanced. The Abstract of the paper is here. For anyone who wants to read the entire study it is here- It is in pdf format, so you will need Adobe Acrobat to download it.

The findings of the study were something of a surprise because they showed that 57% of the men in the study had gone on to treatment in the first two years after diagnosis and 73% had gone on to treatment in the four years after diagnosis. This led the researchers to conclude that Watchful Waiting might be better defined as temporarily deferred therapy - yet another expression!!

I wondered why there was such a difference in the number of men who had chosen to move off Watchful Waiting in this study because I had seen another study that showed about 30% had moved on in the first two years - quite a difference.

The answer seems to be because many of the men the men chosen for the study under discussion had diagnoses that were such that they should, perhaps, not have been considered for Watchful Waiting. Generally speaking the view seems to have developed that men with what has been termed an 'insignificant' tumour are the ones who might benefit from Watchful Waiting. The definition of insignificant tumour used by the Brady Institute at Johns Hopkins is:

1. Nonpalpable
2. Stage T1c
3. Percent free PSA 15 or greater
4. Gleason less than 7
5. Less than three needle cores with none greater than 50% tumour.

When I looked at the details of the men in the study I found:

1. Nonpalpable: 35% of the men in the study had palpable disease - they were staged at T2a, T2b, T2c. It is not recommended that men at this stage should defer treatment and indeed this study showed that a palpable disease was the main predicator for progression to treatment.

2. Stage T1c: Only 60% of the men in the study were staged T1c

3. Percent of fPSA was not given, BUT 39% had a PSA between 10 ng/ml and 20 ng/ml and 50% of the men had a PSA Doubling Time estimated at 5 years or less. These features are not ones that are considered good pointers for a successful Watchful Waiting regimen.

4. Gleason less than 7: The protocol of the study excluded any man with a Gleason Grade of 4 or more, so only men with Gleason Scores of 3+3= 6 or less considered. 6% of the men had GS of 4 or less and 38% had no GS assigned to them! The notation was that the biopsy sample was TSTG (Too Small To Grade). It is not clear how these men were diagnosed with PCa, but presumably they could have had a GS of anything between 2 and 10.

5. Less than three needle cores. 13% of the men had three needle cores. The percentage of positive biopsy material was not identified in the study.

Given these details, it is hardly surprising to find that the men went on to treatment fairly rapidly, half the men commencing treatment within 9 months of diagnosis. Unfortunately there is no correlation between the parameters of the diagnosis and the speed of treatment (or at least I can't find one), but what is interesting is that PSA doubling speed is the primary motivation for seeking treatment, with palpable tumour being the second predictor. So it seems likely that most of the men seeking early treatment might well have been men who would not have been recommended for Watchful Waiting in the first place.

Only 24% of the men had a second biopsy. 60% of these men had no change: 6% had a decrease in their GS on the second biopsy. 83% of the men with a lower GS and 77% of the biopsied men went on to have treatment. I think this demonstrates the psychological effect of Watchful Waiting, although of course, these men may all have had high PSA numbers or a rapid doubling time.

The study records 2 PCa related deaths and 3 cases of metastatic disease in the 313 men whose records were included in the study. The range of follow up in the study was between 0.5 and 10.5 years with a median of 3.8 years. There are no data given regarding these five cases as to time or diagnosis.

The study also showed that there was little probability of any of the men (about 26% of the total) who remained on Watchful Waiting moving on to definitive therapy. Of course the $64,000 question is this: If the study had only included the men whose diagnosis fell within the accepted definition of insignificant disease, what percentage would have remained on Watchful Waiting?

Site Last Updated Monday, May 10, 2004. 15:24:45