Biopsias de saturación para la detección de cáncer de próstata: efectividad, seguridad y factores predictivos / Saturation biopsies for prostate cancer detection: effectiveness, safety and predictive factors

RESUMEN

OBJETIVO: Determinar la rentabilidad y seguridad de las biopsias de saturación para la detección del cáncer de próstata (CaP), e identificar variables relacionadas con la presencia del tumor.MÉTODOS: Revisamos de forma transversal y retrospectiva 144 biopsias de saturación (enero/06-julio/09). Los criterios de inclusión fueron al menos 2 sets de biopsias sin evidencia de malignidad y cifras de Antígeno Prostático Específico (PSA) > 10 ng/ml o cinética de PSA sugestiva de malignidad (velocidad > 0,75 ng/ml/año) y pacientes con atipias en biopsia/s previa/s. Las variables analizadas fueron edad, tacto rectal sospechoso (TRS), PSA total, cociente PSA libre/total, volumen prostático, densidad de PSA, anatomía patológica previa, número de cilindros obtenidos y complicaciones. Se analiza estadísticamente mediante test de CHI-2, t de Student y regresión logística(AU)

ABSTRACT

OBJECTIVES: To determine the effectiveness and safety of saturation biopsies for prostate cancer detection of and to identify predictive variables for cancer.METHODS: We conducted a retrospective transversal study in which we analyzed 144 saturation biopsies (January ‘06 - July ‘09). Inclusion criteria at least two sets of biopsies without evidence of malignancy and Prostate Specific Antigen (PSA) levels >10ng/ml or PSA kinetics suggestive of malignancy (rate >0.75ng/ml/year) and patients with atypia in a previous biopsy.The variables analyzed were age, abnormal digital rectal examination (DRE), total PSA, free/total PSA ratio, prostate volume, PSA density, previous histopathology, number of cylinders obtained and complications. Statistical analysis was performed using the Chi-square test, Student’s t-test and logistic regression.RESULTS: Mean age was 66 years (SD ± 6.4), mean total PSA 14.4 ng/ml (SD ± 12.6), mean free/total PSA ratio 0.09 (SD ± 0.09), mean prostate volume 61.6 cc (SD ± 27.4), mean PSA density 0.27 (SD ± 0.26) and mean number of cylinders obtained 30.45 (SD ± 3.8).We diagnosed 32% of the patients with prostatic adenocarcinoma. We observed PSA density was higher in the prostate cancer group, 0.39 (SD ± 0.36), compared to 0.21 (SD ± 0.18) in patients without cancer (p=0.003). Adenocarcinoma was found in 58% of the biopsies in patients with suspicious DRE, compared to 28% with normal DRE (p=0.009). Mean prostate volume in the prostate cancer group was 52.5 (SD ± 24.7) compared to 66.0 (SD ± 27.7) in the group without cancer (p=0.006).In the multivariate analysis, the PSA density (p=0.02; 95% CI 1.36 - 37.36) was the only variable that independently predicted the presence of adenocarcinoma. No statistically significant differences were found in either univariate or multivariate analysis for the remaining variables analyzed. The incidence of complications was similar to that described in the literature for other series(AU)