Sometimes, apparently, we need to prove what would appear (at least at first sight) to be obvious.
D’Amico et al. have just published results demonstrating that continuing enlargement of the prostate in men receiving neoadjuvant hormone therapy prior to radiation therapy for treatment of T1c-T3cN0M0 disease is a significant indicator of future risk of PSA failure.
The language in even the abstract of this paper is “dense” and difficult to interpret. However, the authors’ stated goal was to determine whether a change in tumor volume during 2 months of neoadjuvant androgen suppression therapy prior to radiation therapy and a further 6 months of adjuvant hormone therapy was a risk factor for later disease recurrence. Tumor volumes were assessed using endorectal coil MRIs.
They enrolled 133 evaluable patients into this trial (of 180 patients initially considered to be eligible) between 1997 and 2001. After a median follow up of 6.7 years, there was a significant increase in the risk of PSA failure in men with increasing tumor volume (as determined by endorectal MRI) during the initial 2 months of neoadjuvant hormone therapy. Specifically, PSA failure was significantly more likely in men with, compared with men without, an endorectal MRI-defined increase in tumor volume (38 percent vs. 19 percent; p = 0.032) at 5 years.
Why would such a result appear to be obvious? Because if the prostate volume increases during the first two months of neoadjuvant hormone therapy, then clearly the prostate is continuing to grow despite the use of hormone therapy. This would suggest that a significant percentage of cells within the prostate are not responding to the hormone therapy, and therefore that there is a high risk that the patient is going to have progressive disease. Surely any man who does not respond to hormone therapy this early in his disease is at risk for progressive disease for the simple reason that he has disease that is hormone independent?
It would seem that the issue that D’Amico and his colleagues are really trying to address here is whether “local control” of the hormone refractory prostate cancer tissue using radiotherapy can impact biochemical disease recurrence (i.e., a rising PSA) in such patients. Apparently radiotherapy does not have that effect.
Filed under: Uncategorized
