Neoadjuvant androgen deprivation for prostate volume reduction: the optimal duration in prostate cancer radiotherapy.
OBJECTIVE
For locally advanced prostate cancer, the results of radiotherapy are improved by combination with androgen deprivation therapy. Volume reduction achieved with neoadjuvant hormonal treatment can facilitate dose escalation without increasing the toxicity. The optimal duration of hormonal treatment, however, is unknown. The endpoint of this study is the optimal duration of androgen deprivation for prostate volume reduction in a cohort of patients scheduled for external beam radiotherapy.


METHODS
Twenty patients scheduled for external beam radiotherapy with cT2-3No/xMo prostate cancer were treated with a luteinizing hormone releasing hormone agonist (busereline) and nonsteroidal anti-androgen (nilutamide) for 9 months consecutively. Repeated CT scan examination was performed 3-monthly to measure prostate volumes until the start of radiation therapy. The analysis of volume reduction was performed with the Wilcoxon signed ranks test.


RESULTS
The baseline median prostate volume for the cohort of patients was 82 cc (95% CI: 61-104 cc) with a median volume reduction of 31% (95% CI: 26%-35%) (P < 0.0001) after 3 months of androgen deprivation. Between 3 and 6 months, a median volume reduction of 9% (95% CI: 4%-14%) (P < 0.0001) was observed. The effect was more pronounced in large prostates (>60 cc) than in small prostates (≤60 cc). In the total cohort of patients no significant volume reduction occurred between 6 and 9 months of maximal androgen blockade (MAB).


CONCLUSIONS
In this study, we have shown that the most significant prostate volume reduction is achieved after 3 months of MAB with a maximum reduction after 6 months. Therefore, the optimal duration of neoadjuvant androgen deprivation to reduce prostate volume before prostate cancer radiotherapy is 6 months. In small prostates 3 months of hormonal treatment may be enough for maximal volume reduction.
Langenhuijsen
Johan F
JF
Department of Urology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. h.langenhuijsen@uro.umcn.nl
van Lin
Emile N
EN
Hoffmann
Aswin L
AL
Spitters-Post
Ilse
I
Alfred Witjes
J
J
Kaanders
Johannes H
JH
Mulders
Peter F
PF
D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use*; D002064:Buserelin / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant; D015331:Cohort Studies; D004359:Drug Therapy, Combination; D005300:Fertility Agents, Female / Q000627:therapeutic use*; D006801:Humans; D048289:Imidazolidines / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy*; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome
D000726:Androgen Antagonists; D005300:Fertility Agents, Female; D048289:Imidazolidines; C021277:nilutamide; D002064:Buserelin