Risk of all-cause and prostate cancer-specific mortality after brachytherapy in men with small prostate size.
BACKGROUND
Brachytherapy for prostate cancer can be technically challenging in men with small prostates (≤20 cc), but it is unknown whether their outcomes are different than those of men with larger prostates.


METHODS
We studied 6,416 men treated with brachytherapy in one of 21 community-based practices. Cox regression and Fine and Gray's regression were used to determine whether volume ≤20 cc was associated with a higher risk of all-cause mortality (ACM) or prostate cancer-specific mortality (PCSM), respectively, after adjustment for other known prognostic factors.


RESULTS
443 patients (6.9%) had a prostate volume ≤20 cc. After a median follow-up of 2.91 years (interquartile range, 1.06-4.79), volume ≤20 cc was associated with a significantly higher risk of ACM (adjusted hazard ratio = 1.33 [95% CI 1.08-1.65], p = 0.0085) with 3-year estimates of ACM for ≤20 cc vs. >20 cc of 13.0% vs. 6.9% (p = 0.028). Only 23 men (0.36%) have died of prostate cancer, and no difference was seen in PCSM by volume (p = 0.4).


CONCLUSIONS
Men with small prostates at the time of implant had a 33% higher risk of ACM, and the underlying cause of this remains uncertain. No increase in PCSM was observed in men with volume ≤20cc, suggesting that a small prostate should not in itself be a contraindication for brachytherapy, but inasmuch as absolute rates of PCSM were small, further follow-up will be needed to confirm this finding.
Nguyen
Paul L
PL
Department of Radiation Oncology, Dana Farber Cancer Institute and Brigham and Women's Hospital, Boston, MA 02115, USA. E-pnguyen@LROC.harvard.edu
Chen
Ming H
MH
Choueiri
Toni K
TK
Hoffman
Karen E
KE
Hu
Jim C
JC
Martin
Neil E
NE
Beard
Clair J
CJ
Dosoretz
Daniel E
DE
Moran
Brian J
BJ
Katin
Michael J
MJ
Braccioforte
Michelle H
MH
Ross
Rudi
R
Salenius
Sharon A
SA
Kantoff
Philip W
PW
D'Amico
Anthony V
AV
D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use; D001918:Brachytherapy / Q000379:methods; D002423:Cause of Death; D000075202:Contraindications; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009929:Organ Size; D011467:Prostate / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy*; D012044:Regression Analysis
D000726:Androgen Antagonists