Population-based study of cardiovascular mortality among patients with prostate cancer treated with radical external beam radiation therapy with and without adjuvant androgen deprivation therapy at the British Columbia Cancer Agency.
OBJECTIVE
There are conflicting studies of the impact of androgen deprivation therapy (ADT) on cardiovascular (CV) mortality among prostate cancer patients receiving curative intent external beam radiation therapy (EBRT). We assessed the impact of ADT on CV mortality in patients treated in British Columbia.


METHODS
Provincial pharmacy and radiotherapy databases were linked to the provincial cancer registry, and defined a cohort of patients treated with curative intent EBRT between 1998 and 2005. We determined the duration of ADT and the cumulative incidence of CV death. We compared death from CV disease with and without ADT, and by duration of ADT using competing risk analysis and Fine and Gray multivariant analysis. A total of 600 randomly selected patients were reviewed to determine baseline CV disease, CV risk factors, and Charlson Index.


RESULTS
Of 5,948 prostate cancer patients treated with radical intent EBRT, of whom 1,933 were treated without ADT, 674 received ADT for ≤ 6 months and 3,341 received > 6 months of ADT. The cumulative CV mortality at 7 years was 2.6% (95% confidence interval [CI] 1.9-3.5%), 2.1% (95% CI = 1.2-3.5%), and 1.4 (95% CI = 1.0-2.0%) for patients with no ADT, ≤ 6 months of ADT, and >6 months of ADT, respectively (Gray's p = 0.002). Baseline CV disease and risk factors were more prevalent in the no-ADT group compared with the >6-month ADT group.


CONCLUSIONS
This study demonstrated a lower CV mortality rate among patients treated with longer durations of ADT than those treated without ADT. These differences likely relate to selection of patients for ADT rather than effect of ADT itself.
Kim
Julian
J
University of British Columbia, Vancouver, BC, Canada.
Vaid
Moninder
M
Tyldesley
Scott
S
Woods
Ryan
R
Pickles
Tom
T
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000009:adverse effects* / Q000627:therapeutic use; D001955:British Columbia / Q000453:epidemiology; D002173:Cancer Care Facilities; D002318:Cardiovascular Diseases / Q000401:mortality*; D002423:Cause of Death; D003131:Combined Modality Therapy / Q000379:methods / Q000401:mortality; D016001:Confidence Intervals; D003324:Coronary Artery Disease / Q000401:mortality; D016757:Death, Sudden, Cardiac / Q000209:etiology; D006333:Heart Failure / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000401:mortality; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D012307:Risk Factors; D013997:Time Factors
D000726:Androgen Antagonists