Prediction of biochemical recurrence after radical prostatectomy. New tool for selecting candidates for adjuvant radiation therapy

Abstract

Objective

To design a risk summation to select patients for adjuvant radiation therapy after prostatectomy.

Materials and method

A retrospective study was conducted on 629 patients with localized prostate cancer (pN0–pNx) who were treated with prostatectomy and with a prostate-specific antigen (PSA) value <0.2 ng/ml at 2–3 months. Biochemical recurrence was defined as a PSA >0.4 ng/ml. A multivariate Cox regression analysis was performed. A score (0–2) was assigned according to the hazard ratio of the significant variables. The score summation defined the risk summation.

Results

A total of 19.7% of the patients were pT3, 24.2% had a Gleason score ≥8, and 26.3% had positive surgical margins. The median follow-up was 82 months. Some 26.6% of the patients experienced biochemical recurrence. The identified prognostic variables independent of biochemical recurrence were a Gleason score = 7 (4 + 3) (HR, 2.01; p = .008), a Gleason score ≥8 (HR, 3.07; p < .001), a pT3b stage (HR, 1.93; p = .008) and a positive surgical margin (HR, 2.20; p < .001). We assigned 0 points to patients without risk prognosis variables; 1 point to patients with Gleason scores = 7 (4 + 3), pT3b or positive surgical margins; and 2 points to patients with Gleason scores ≥8. The patients with a risk summation ≤2 had >50% survival free of biochemical recurrence at 5 and 8 years. In contrast, the patients with a risk summation ≥3 had <44% survival free of biochemical recurrence.

Conclusion

The patients with a risk summation ≤2 did not benefit from adjuvant radiation therapy, while the patients with a risk summation ≥3 might benefit from adjuvant radiation therapy.

Resumen

Objetivo

Diseñar un sumatorio de riesgo para la selección de pacientes para radioterapia adyuvante después de prostatectomía.

Material y método

Estudio retrospectivo de 629 pacientes con cáncer de próstata localizado y pN0-pNx tratados con prostatectomía y con un PSA a los 2-3 meses < 0,2 ng/ml. Recidiva bioquímica si PSA > 0,4 ng/ml. Análisis multivariante mediante regresión de Cox. Asignación de puntuación (0-2) en función del HR de las variables significativas. El sumatorio de las puntuaciones definió el sumatorio de riesgo.

Resultados

El 19,7% pT3, 24,2% Gleason ≥ 8 y el 26,3% de márgenes quirúrgicos positivos. Mediana de seguimiento de 82 meses. Recidiva bioquímica el 26,6%. El Gleason = 7 (4 + 3) (HR = 2,01, p = 0,008), el Gleason ≥ 8 (HR = 3,07, p < 0,001), el estadio pT3b (HR = 1,93, p = 0,008) y el margen quirúrgico positivo (HR = 2,20, p < 0,001) se identificaron como variables pronosticas independientes de recidiva bioquímica. Se asignó 0 puntos a los pacientes sin variables pronósticas de riesgo, un punto a los pacientes con Gleason = 7 (4 + 3), pT3b o márgenes quirúrgicos positivos y 2 puntos si Gleason ≥ 8. Los pacientes con un sumatorio de riesgo ≤ 2 tuvieron una supervivencia libre de recidiva bioquímica a los 5 y 8 años superior al 50%, en cambio, los pacientes con un sumatorio de riesgo ≥ 3 tuvieron una supervivencia libre de recidiva bioquímica inferior al 44%.

Conclusión

Los pacientes con un sumatorio de riesgo ≤ 2 no se beneficiarían de radioterapia adyuvante, mientras que los pacientes con un sumatorio de riesgo ≥ 3 pudieran beneficiarse de radioterapia adyuvante.