RESUMEN
Prediction of extraprostatic disease in clinically localized prostate cancer is relevant for treatment planning of the disease. The purpose of this study was to explore the usefulness of the percentage of positive biopsy cores to predict the chance of extraprostatic cancer.
We evaluated 1787 patients with localized prostate cancer submitted to radical prostatectomy. The percentage of positive cores in prostate biopsy was correlated with the pathologic outcome of the surgical specimen. In the final analysis, a correlation was made between categorical ranges of positive cores (10% intervals) and the risk of extraprostatic extension and/or bladder neck invasion, seminal vesicles involvement or metastasis to iliac lymph nodes. Student's t test was used for statistical analysis.
For each 10% of positive cores we observed a progressive higher prevalence of extraprostatic disease. The risk of cancer beyond the prostate capsule for <10% positive biopsy cores was 7.4% and it increased to 76.2% at the category 90-100% positive cores. In patients with Gleason grade 4 or 5, the risk of extraprostatic cancer prostate was higher than in those without any component 4 or 5.
The percentage of positive cores in prostate biopsy can predict the risk of cancer outside the prostate. Our study shows that the percentage of positive prostate biopsy fragments helps predict the chance of extraprostatic cancer and may have a relevant role in the patient's management.
Asunto(s)
Anciano , Humanos , Masculino , Persona de Mediana Edad , Adenocarcinoma/patología , Próstata/patología , Neoplasias de la Próstata/patología , Adenocarcinoma/cirugía , Metástasis Linfática , Clasificación del Tumor , Estadificación de Neoplasias , Invasividad Neoplásica/patología , Antígeno Prostático Específico/sangre , Prostatectomía/métodos , Neoplasias de la Próstata/cirugía , Valores de Referencia , Reproducibilidad de los Resultados , Estudios Retrospectivos , Medición de RiesgoRESUMEN
OBJECTIVES: To establish a formula that estimates tumor volume in localized prostate cancer based on serum prostate specific antigen levels. One of the main prognostic variables in localized prostate cancer is tumor volume, which can be precisely defined only after prostate extirpation. The present study defines a simple method that allows for estimation of tumor volume before treatment, which can help to establish a better therapeutic strategy for each patient. METHODS: From 1997 to 2002, 735 patients with prostate cancer of stagesT1c-T2c without any previous treatment were submitted to radical prostatectomy. Surgical specimens were evaluated by the same pathologist and the total tumor volume (in cc) and the relative tumor volume (as the percent of the total prostate volume) were determined using the grid morphometric method. Pretreatment serum prostate specific antigen was correlated with tumor volume in each patient using a linear regression model. RESULTS: There were positive correlations between the serum levels of prostate specific antigen and the total tumor volume in cc (p<0.001) and the relative tumor volume as a percentage (p<0.001). For each ng/ml unit increment of serum prostate specific antigen, there was a 0.302 cc increase in total tumor volume and a 0.7 percent increase in relative tumor volume. Total and percent tumor volume could be calculated, respectively, using the formulas Volume (cc) = 3.476 + 0.302 x PSA (ng/ml) and Volume ( percent) = 11.331 + 0.704 x prostate specific antigen (ng/ml). CONCLUSIONS: Tumor volume in patients with prostate cancer can be determined before treatment based on the serum prostate specific antigen levels.