Predictors of prostate cancer-specific mortality in elderly men with intermediate-risk prostate cancer treated with brachytherapy with or without external beam radiation therapy.
OBJECTIVE
To identify clinical factors associated with prostate cancer-specific mortality (PCSM), adjusting for comorbidity, in elderly men with intermediate-risk prostate cancer treated with brachytherapy alone or in conjunction with external beam radiation therapy.


METHODS
The study cohort comprised 1,978 men of median age 71 (interquartile range, 66-75) years with intermediate-risk disease (Gleason score 7, prostate-specific antigen (PSA) 20 ng/mL or less, tumor category T2c or less). Fine and Gray's multivariable competing risks regression was used to assess whether prevalent cardiovascular disease (CVD), age, treatment, year of brachytherapy, PSA level, or tumor category was associated with the risk of PCSM.


RESULTS
After a median follow-up of 3.2 (interquartile range, 1.7-5.4) years, the presence of CVD was significantly associated with a decreased risk of PCSM (adjusted hazard ratio, 0.20; 95% CI 0.04-0.99; p = 0.05), whereas an increasing PSA level was significantly associated with an increased risk of PCSM (adjusted hazard ratio 1.14; 95% CI 1.02-1.27; p = 0.02). In the absence of CVD, cumulative incidence estimates of PCSM were higher (p = 0.03) in men with PSA levels above as compared with the median PSA level (7.3 ng/mL) or less; however, in the setting of CVD there was no difference (p = 0.27) in these estimates stratified by the median PSA level (6.9 ng/mL).


CONCLUSIONS
In elderly men with intermediate-risk prostate cancer, CVD status is a negative predictor of PCSM and affects the prognostic capacity of pretreatment PSA level. These observations support the potential utility of prerandomization stratification by comorbidity to more accurately assess prognostic factors and treatment effects within this population.
Nanda
Akash
A
Harvard Radiation Oncology Program, Brigham & Women's Hospital/Dana-Farber Cancer Institute, Boston, MA 02115, USA. ananda@partners.org
Chen
Ming-Hui
MH
Moran
Brian J
BJ
Braccioforte
Michelle H
MH
Dosoretz
Daniel
D
Salenius
Sharon
S
Katin
Michael
M
Ross
Rudi
R
D'Amico
Anthony V
AV
D000368:Aged; D001918:Brachytherapy / Q000379:methods*; D002318:Cardiovascular Diseases / Q000150:complications / Q000401:mortality*; D002423:Cause of Death; D002588:Cesium Radioisotopes / Q000627:therapeutic use; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D009367:Neoplasm Staging; D010165:Palladium / Q000627:therapeutic use; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000150:complications / Q000401:mortality* / Q000532:radiotherapy*; D011868:Radioisotopes / Q000627:therapeutic use; D012044:Regression Analysis
D002588:Cesium Radioisotopes; D007457:Iodine Radioisotopes; D011868:Radioisotopes; D010165:Palladium; D017430:Prostate-Specific Antigen