Selecting Patients with Favorable Risk, Grade Group 2 Prostate Cancer for Active Surveillance-Does Magnetic Resonance Imaging Have a Role?

PURPOSE: The National Comprehensive Cancer Network® recommends that selected men with grade group 2 prostate cancer be considered for active surveillance. However, selecting which patients with grade group 2 disease can be safely managed by active surveillance remains controversial. The aim of this study was to evaluate the association of multiparametric magnetic resonance imaging with adverse pathology in the radical prostatectomy specimen of men with favorable risk grade group 2 prostate cancer, which could help select patients for active surveillance. MATERIALS AND METHODS: We retrospectively analyzed a cohort of patients with favorable grade group 2 disease who underwent radical prostatectomy between 2010 and 2019. Preoperative multiparametric magnetic resonance imaging was scored as negative (no identifiable lesion), positive (identifiable lesion) or equivocal. We defined a multivariable logistic regression model with multiparametric magnetic resonance imaging score as the predictor and adverse pathology (up staging to T3a/b disease, upgrading to ≥grade group 3 or lymph node invasion) as the outcome, adjusting for preoperative prostate specific antigen, biopsy Gleason grade, clinical stage, and number of negative and positive prostate biopsy cores. Secondary outcomes of biochemical recurrence, grade group upgrading alone and the added value of incorporating multiparametric magnetic resonance imaging data into the nomogram were also investigated. RESULTS: We identified 1,117 patients with favorable risk grade group 2 disease who underwent radical prostatectomy. Positive multiparametric magnetic resonance imaging was associated with higher rates of adverse pathology (OR 2.55, 95% CI 1.75-3.40, p <0.0001) and upgrading (OR 3.89, 95% CI 2.00-7.56, p <0.0001). However, as our study included only grade group 2 patients who underwent radical prostatectomy, our cohort may represent a higher risk group than grade group 2 patients as a whole. Adding multiparametric magnetic resonance imaging results to a standard prediction model led to higher net benefit on decision curve analysis. An identifiable lesion on multiparametric magnetic resonance imaging was associated with an increased risk of aggressive pathological features in the radical prostatectomy specimen of patients with favorable risk grade group 2 prostate cancer who were potential active surveillance candidates. This information could be used to inform biopsy strategy, counsel patients on treatment options and guide strategies for those on active surveillance. CONCLUSIONS: Combining multiple magnetic resonance imaging modalities (multiparametric magnetic resonance imaging) provides a more accurate prediction of the risk presented by prostate cancer than current prediction methods. In this study, positive magnetic resonance imaging results approximately doubled the chances that a patient with favorable risk prostate cancer would be found to have adverse pathology when their prostate was removed. Thus, multiparametric magnetic resonance imaging could help select patients with favorable risk cancer who may be good candidates for active surveillance, and help guide biopsy and surveillance strategies for such patients.

Updated postoperative nomogram incorporating the number of positive lymph nodes to predict disease recurrence following radical prostatectomy.

BACKGROUND: A significant number of patients with minimal lymph node disease at radical prostatectomy (RP) and pelvic lymph node dissection (PLND) have better than expected long-term outcomes. We explored whether stratification by number of positive nodes enhances our institutional prediction model for biochemical recurrence after RP. METHODS: A total of 7789 patients underwent RP and pelvic lymph node dissection from 1995 to 2012 at a tertiary referral center. We compared two recurrence prediction models: one incorporated lymph node invasion and the other tracked the number of positive nodes. Existing and updated models' discrimination was assessed using Harrell's c-index and calibration. The 10-fold cross-validation was performed to correct for model overfitting. RESULTS: Of the 491 patients (6.3%) harboring nodal disease, 387 (5.0%) had 1-2 positive nodes and 104 (1.3%) had ⩾3 positive nodes. Data on number of positive nodes did not improve the c-index for the cohort as a whole. When we assessed discrimination for node-positive patients only, c-index for the model with number of positive nodes was 0.01 (95% confidence interval 0.001-0.024) higher than the model with lymph node invasion. Illustrative examples were provided by reclassification tables using number of positive lymph nodes. For instance, 40 of 7789 patients would be reclassified with a cutoff point of 50% for biochemical recurrence at 1 year, and 36 of 7789 patients would be reclassified with a cutoff point of 40% for biochemical recurrence at 10 years. CONCLUSIONS: Stratification by number of positive lymph nodes provided additional discriminative ability for evaluating risk in node-positive patients. Pending external validation, this model could be used for patient counseling and clinical trial stratification in this subpopulation.

Number of metastatic lymph nodes as determinant of outcome after salvage radical prostatectomy for radiation-recurrent prostate cancer. / Número de ganglios linfáticos metastásicos como determinante de los resultados de la prostatectomía radical de rescate en el cáncer de próstata de recidivante tras radioterapia.

BACKGROUND: Presence of lymph node metástasis (LNM) at salvage radical prostatectomy (sRP) is associated with poor outcome. Predictors of outcome in this context remain undetermined. ThE objective was to assess the role of number of positive lymph node on outcome of patients with LNM after sRP and for radio-recurrent prostate cancer. MATERIAL AND METHODS: We analyzed data from a consecutive cohort of 215 men treated with sRP at a single institution. We used univariate Cox proportional hazard regression models for biochemical recurrence (BCR) and metastatic outcomes, with prostate-specific antigen, Gleason score, extraprostatic extension, seminal vesicle invasion, time between radiation therapy and sRP, and number of positive nodes as predictors. RESULTS: Of the 47 patients with LNM, 37 developed BCR, 11 developed distant metastasis and 4 died with a median follow-up of 2.3 years for survivors. The risk of metastases increased with higher pre-operative PSA levels (HR 1.19 per 1ng/ml; 95% CI: 1.06-1.34; P=.003). The remaining predictors did not reach conventional levels of significance. However, removal of 3 or more positive lymph nodes demonstrated a positive association, as expected, with metastatic disease (HR 3.44; 95% CI: 0.91-13.05; P=.069) compared to one or 2 positive nodes. Similarly, the presence of extraprostatic extension, seminal vesicle invasion and Gleason grade greater than 7 also demonstrated a positive association with higher risk of metástasis, with hazard ratios of 3.97 (95% CI: 0.50, 31.4; P=.2), 3.72 (95% CI: 0.80-17.26; P=.1), and 1.45 (95% CI: 0.44-4.76; P=.5), respectively. CONCLUSIONS: In patients with LNM after sRP for radio-recurrent prostate cancer, the risk of distant metástasis is likely to be influenced by the number of positive nodes (3 or more), high preoperative PSA, Gleason grade and advanced pathologic stage. These results are consistent with the findings of number of nodes (1 to 2 vs. 3 or more nodes positive) as a prognostic indicator after primary radical prostatectomy and strengthen the plea for a revision of the nodal staging for prostate cancer.