Prostate cancer modality time trend analyses from 1973 to 2004: a Surveillance, Epidemiology, and End Results...

Although specialized (urology/radiotherapy [RT]) databases have been used to measure practice patterns in nonmetastatic prostate cancer, the Surveillance, Epidemiology, and End Results (SEER) registry has not yet been employed for this task in detail. Our objectives were to analyze time trends in the use of surgery and RT and type of RT (external beam RT [EBRT], brachytherapy [Brachy] or combination EBRT + Brachy [Combo]).

Eight lakh twenty-three thousand two hundred ninety-four patients in the SEER public-use registry (1973-2004) were identified. Modality time-trend curves were plotted for the whole group and by (a) grade (well-differentiated [WD], moderately differentiated [MD], and poorly differentiated [PD]) and (b) stage (modified AJCC stage 0-I, stage II, and stage III). A nonparametric (Spearman) test was used to assess correlation of diagnosis year with (a) percentage use of RT and (b) percentage use of EBRT, Brachy, and Combo.

RT use steadily increased from 9.1% in 1973 to 26.0% in 2004 (P < 0.001). Within RT, EBRT use decreased from 99.3% to 59.3% (P < 0.001), Brachy use increased from 0.0% to 29.6% (P < 0.001), and Combo use increased from 0.0% to 11.1% (P < 0.001). Similar time-trend curves to the overall group were observed for all grades and for stage 0 to II patients; stage III time trends were somewhat more static.

Our SEER analysis demonstrated an expected rise in RT use (and relative increase in Brachy) paralleling the rise in evidence for modern EBRT and Brachy efficacy/safety. Within stated limitations, these results can serve as national benchmarks to assess prevailing referral patterns in a given institution or region.