Changes in the paradigm for the diagnosis of prostate cancer.
El reciente estudio denominado PRECISION (Prostate Evaluation for Clinically Important disease: Sampling using Image-guidance Or Not?) publicado en la renombrada revista The New England Journal of Medicine ha mostrado resultados que impactan en el diagnóstico del cáncer de próstata. En este estudio internacional, 500 hombres con sospecha de cáncer de próstata por aumento del PSA (Antígeno Prostático Especifico) fueron separados en dos grupos.
In group 1, we performed the diagnostic method of traditional using a prostate biopsy transrectal directed by ultrasound and doing 12 shots of biopsy and in group 2, the diagnosis was obtained based on the findings of Magnetic Resonance imaging Multiparamétrica of the prostate (RMNmp). In the second group, if the resonance was abnormal, they did a biopsy of the prostate by FUSION with a software that integrates the images of mri with ultrasound, making only biopsies of the suspicious area of the resonance.
The primary objective of this study was to evaluate the detection rate of clinically significant prostate cancer; secondary objectives included the detection rate of clinically insignificant cancer (defined as organ-limited disease with tumor volume <0.5 cm3, with Gleason score 6, for which treatment is not necessary and will not generate benefits for patients).
In Group 1 of the biopsy traditional, the detection rate of cancer clinically significant was 26%, and the detection rate of cancer clinically insignificant was 22%. In Group 2, the fusion with Mri, the detection rate of cancer clinically significant in patients who will require treatment increased approximately double with 38% and the detection rate of cancer insignificant decreased to 9% by avoiding to treat cancers that do not require it.
Therefore, despite the fact that more than a quarter of the men in the way of Resonance, in reality, they avoided a biopsy, the detection rate of prostate cancer clinically significant was much higher in this arm. In addition, the rate of detection of cancer clinically insignificant was much lower (i.e., they reduced the excess of diagnosis). And all this with only four shots of biopsy, compared with 12 shots of biopsies traditional with the ultrasound.
These findings should lead to a change for the patients on the pathway in the diagnosis of early prostate cancer in two ways:
1. All patients with a clinical suspicion of prostate cancer should provide a magnetic resonance imaging as part of its way of making decisions before the biopsy.
2. Should be offered a biopsy of the merger to all patients with an anomaly in its resonance.
A reason of concern, as are patients with a normal mri (28% of patients), despite clinical suspicion of prostate cancer, did not have a biopsy. How many cancers clinically significant could lose by not offering a biopsy these patients? An answer of what we would find, the offers studio PROMIS (Prostate MR Imaging Study) that included a biopsy extensive for patients with an mri normal.
En el estudio PROMIS, el valor predictivo negativo de la Resonancia para detectar cualquier tipo de cáncer 4 es del 76%, es decir, hasta 1 de cada 4 hombres tendrá cáncer de patrón 4 en la biopsia transperineal. Sin embargo, no se perdieron los cánceres primarios del patrón 4 en la RMN. Se podría aceptar la ausencia de algunos cánceres de patrón Gleason 4 en algunos hombres, siempre que el “seguimiento de rutina” sea adecuado.
This could provide sufficient evidence to adopt fully the indication of the Resonance in the approach for the early detection of prostate cancer. Based on the study PROMIS, published in The Lancet in 2017, in addition to the study, the PRECISION, the results provide the knowledge to fully integrate the magnetic resonance imaging in the evaluation of men with suspicion of prostate cancer. The era of prostate biopsy blind randomised possibly have done, except perhaps in those patients in whom Mri is contraindicated.
