Prostate cancer is the most common cancer among American men, projected to account for over 240,000 new cases in 1995.<sup>25 Wingo P.A., Tong T., Bolden S. Cancer statistics, 1995 CA Cancer J Clin 1995 ;  45 : 8  [cross-ref]

Haga clic aquí para ir a la sección de Referencias</sup> The advent of prostate-specific antigen (PSA) screening for prostate cancer has led to more cancers being discovered at an early, apparently localized stage.<sup>3 Catalona W.J., Smith D.S., Ratliff T.L., Basler J.W. Detection of organ-confined prostate cancer is increased through prostate-specific antigen-based screening JAMA 1993 ;  270 : 948

Haga clic aquí para ir a la sección de Referencias</sup> Potentially curative treatments for localized prostate cancer include radical prostatectomy and external beam radiation therapy (XRT).<sup>1 Adolfsson J., Steineck G., Whitmore W.F. Recent results of management of palpable clinically localized prostate cancer Cancer 1993 ;  72 : 310  [cross-ref]

Haga clic aquí para ir a la sección de Referencias</sup> Another use of serum PSA is to detect early recurrence or persistence of prostate cancer following apparently curative treatment for clinically localized prostate cancer.<sup>2 Catalona W.J., Smith D.S. 5-Year tumor recurrence rates after anatomical radical retropubic prostatectomy for prostate cancer J Urol 1994 ;  152 : 1837

Haga clic aquí para ir a la sección de Referencias, 4 D'amico A.V., Whittington R., Malkowicz S.B. , y al. A multivariate analysis of clinical and pathological factors that predict for prostate specific antigen failure after radical prostatectomy for prostate cancer J Urol 1995 ;  154 : 131

Haga clic aquí para ir a la sección de Referencias, 15 Partin A.W., Pound C.R., Clemens J.Q. , y al. Serum PSA after anatomic radical prostatectomy Urol Clin North Am 1993 ;  20 : 713

Haga clic aquí para ir a la sección de Referencias</sup> The current definition for cure following radical prostatectomy includes an undetectable serum PSA. A serum PSA of less than 1.5 ng/dL has been suggested as an end point in patients after XRT.<sup>2 Catalona W.J., Smith D.S. 5-Year tumor recurrence rates after anatomical radical retropubic prostatectomy for prostate cancer J Urol 1994 ;  152 : 1837

Haga clic aquí para ir a la sección de Referencias, 4 D'amico A.V., Whittington R., Malkowicz S.B. , y al. A multivariate analysis of clinical and pathological factors that predict for prostate specific antigen failure after radical prostatectomy for prostate cancer J Urol 1995 ;  154 : 131

Haga clic aquí para ir a la sección de Referencias, 8 Goad J.R., Chang S.-J., Ohori M., Scardino P.T. PSA after definitive radiotherapy for clinically localized prostate cancer Urol Clin North Am 1993 ;  20 : 727

Haga clic aquí para ir a la sección de Referencias, 9 Hancock S.L., Cox R.S., Bagshaw M.A. Prostate-specific antigen after radiotherapy for prostate cancer: A reevaluation of long-term biochemical control and the kinetics of recurrence in patients treated at Stanford University J Urol 1995 ;  154 : 1412  [cross-ref]

Haga clic aquí para ir a la sección de Referencias, 10 Hanks G.E., Hanlon A., Schiltheiss T. , y al. Early prostate cancer: The national results of radiation treatment from the Patterns of Care and Radiation Therapy Oncology Group Studies with prospects for improvement with conformal radiation and adjuvant androgen deprivation J Urol 1994 ;  152 : 1775

Haga clic aquí para ir a la sección de Referencias, 11 Hanks G.E., Lee W.R., Schultheiss T.E. Clinical and biochemical evidence of control of prostate cancer at 5 years after external beam radiation J Urol 1995 ;  154 : 456  [cross-ref]

Haga clic aquí para ir a la sección de Referencias, 15 Partin A.W., Pound C.R., Clemens J.Q. , y al. Serum PSA after anatomic radical prostatectomy Urol Clin North Am 1993 ;  20 : 713

Haga clic aquí para ir a la sección de Referencias</sup> Whether this is an appropriate end point or a lower PSA is necessary is, to date, unknown.

Cure rates from studies prior to the use of PSA are significantly higher than those being found with the use of this serum marker.<sup>7 Frazier H.A., Robertson J.E., Humphrey P.A., Paulson D.F. Is prostate specific antigen of clinical importance in evaluating outcome after radical prostatectomy? J Urol 1993 ;  149 : 516

Haga clic aquí para ir a la sección de Referencias, 19 Schellhammer P.F., El-Mahdi A.M., Wright G.L. , y al. Prostate-specific antigen to determine progression-free survival after radiation therapy for localized carcinoma of the prostate Urology 1993 ;  42 : 13  [cross-ref]

Haga clic aquí para ir a la sección de Referencias</sup> Using clinical nonbiochemical end points, the efficacies of radical surgery and XRT in the treatment of localized prostate cancer have generally been reported to be relatively equivalent, although this remains very controversial.<sup>1 Adolfsson J., Steineck G., Whitmore W.F. Recent results of management of palpable clinically localized prostate cancer Cancer 1993 ;  72 : 310  [cross-ref]

Haga clic aquí para ir a la sección de Referencias, 30 Zietman A.L., Shipley W.U., Coen J.J. Radical prostatectomy and radical radiation therapy for clinical stages T1 to 2 adenocarcinoma of the prostate: New insights into outcome from repeat biopsy and prostate-specific antigen followup J Urol 1994 ;  152 : 1806

Haga clic aquí para ir a la sección de Referencias</sup> Although desperately needed, no recent controlled studies comparing these two modalities have been completed. The only randomized, controlled trial was reported in 1982 by Paulson et al<sup>17 Paulson D.F., Lin G.H., Hinshaw W., Stephani S. Radical surgery versus radiotherapy for adenocarcinoma of the prostate J Urol 1982 ;  128 : 502

Haga clic aquí para ir a la sección de Referencias</sup> for the Uro-Oncology Research Group. In this study, 97 patients with clinically localized prostate cancer, including normal prostatic acid phosphatase levels, negative bone scans, and negative pelvic lymphadenectomies, were randomized to either radical surgery or XRT. Of the 59 patients randomized to XRT, 52 actually received it and 3 had radical surgery. Of the 47 patients randomized to surgery, 38 received it and 4 had XRT. Although this study has been criticized for many reasons, including this high crossover rate and for data analysis by treatment received and not by the treatment randomized to, the results were quite impressive and the study represents the only randomized data available. The results demonstrated that time to first evidence of treatment failure was significantly shorter (p = 0.037) for those treated by XRT than those treated by surgery. In addition, only four patients in the surgery group had evidence of disease progression in the follow-up period, whereas 17 did in the XRT group.

Recently, Zietman et al<sup>30 Zietman A.L., Shipley W.U., Coen J.J. Radical prostatectomy and radical radiation therapy for clinical stages T1 to 2 adenocarcinoma of the prostate: New insights into outcome from repeat biopsy and prostate-specific antigen followup J Urol 1994 ;  152 : 1806

Haga clic aquí para ir a la sección de Referencias</sup> attempted to compare these two modalities by performing a retrospective literature review with particular attention to long-term follow-up inclusive of PSA and concluded that XRT and radical surgery produced similar results. These authors felt that any differences found (i.e., lower long-term control rates with XRT) could be attributed to differences in patient selection, although it is not clear how this was determined. Adolfsson et al<sup>1 Adolfsson J., Steineck G., Whitmore W.F. Recent results of management of palpable clinically localized prostate cancer Cancer 1993 ;  72 : 310  [cross-ref]

Haga clic aquí para ir a la sección de Referencias</sup> reviewed the world's literature to determine the relative efficacies of deferred treatment, radical prostatectomy, and XRT in the treatment of localized prostate cancer. Although this was simply an exhaustive review, not a randomized study, and did not include PSA data, they concluded that 10-year disease-specific survival after surgery was 93%, 83% for deferred therapy and 74% for XRT. Interestingly, mortality due to intercurrent disease was 49.9 per 1000 person-years over the 10-year period in patients treated with deferred therapy, whereas it was 36.3 in those treated with XRT, and only 7 in those treated with surgery, showing significant differences in patient populations between the different treatment groups. This also suggests, however, that those treated with radical surgery had more person-years at risk for prostate cancer progression.

Given the disagreements in the literature concerning the relative efficacies of XRT and surgery in the treatment of clinically localized prostate cancer, we sought to examine the literature with particular attention to posttreatment serum PSA levels. PSA levels are perhaps the most objective and easily obtainable parameter that can be assessed and, in our opinion, the most meaningful surrogate end point.