Radical prostatectomy vs radiotherapy vs observation among older patients with clinically localized prostate cancer: a comparative effectiveness evaluation.
OBJECTIVE
To compare efficacy between radical prostatectomy (RP), radiotherapy and observation with respect to overall survival (OS) in patients with clinically localized prostate cancer (PCa).


METHODS
Using data (1988-2005) from the Surveillance, Epidemiology, and End Results-Medicare linked database, 67 087 men with localized PCa were identified. The prevalence of the initial treatment strategy was quantified according to patients' life expectancy ([LE] <10 vs ≥10 years) at initial diagnosis and according to tumour stage. To reduce the unmeasured bias associated with treatment, we performed an instrumental variable analysis. Stratified (by stage and LE) Cox regression and competing-risks regression analyses were generated for the prediction of OS and cancer-specific mortality, respectively.


RESULTS
Among patients with <10 years of LE, most were treated with radiotherapy (49%) or observation (47%). Among patients with ≥10 years of LE, most received radiotherapy (49%), followed by RP (26%). In men with <10 years of LE, RP and radiotherapy were not different with respect to OS (hazard ratio [HR]: 0.81, 95% confidence interval [CI]: 0.45-1.48, P = 0.499). Conversely, in men with ≥10 years of LE, RP was associated with an improved OS compared with observation (HR: 0.59, 95% CI: 0.49-0.71, P < 0.001) and radiotherapy (HR: 0.66, 95% CI: 0.56-0.79, P < 0.001). Similar results were recorded in competing-risks regression analyses.


CONCLUSIONS
In patients with an estimated LE ≥10 years at initial diagnosis, RP was associated with improved survival compared with radiotherapy and observation, regardless of disease stage.
Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, Montreal, Canada.
Maxine
M
Sun
Jesse D
JD
Sammon
Andreas
A
Becker
Florian
F
Roghmann
Zhe
Z
Tian
Simon P
SP
Kim
Alexandre
A
Larouche
Firas
F
Abdollah
Jim C
JC
Hu
Pierre I
PI
Karakiewicz
Quoc-Dien
QD
Trinh
D000367:Age Factors; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D006801:Humans; D008297:Male; D006278:Medicare; D009367:Neoplasm Staging; D017063:Outcome Assessment, Health Care; D017430:Prostate-Specific Antigen / Q000097:blood*; D011468:Prostatectomy / Q000706:statistics & numerical data; D011471:Prostatic Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D011878:Radiotherapy / Q000706:statistics & numerical data; D018570:Risk Assessment; D018571:Sentinel Surveillance; D014481:United States / Q000453:epidemiology; D057832:Watchful Waiting / Q000706:statistics & numerical data
D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen
observation; prostate cancer; prostatectomy; radiotherapy