Predicting early outcomes in patients with intermediate‐ and high‐risk prostate cancer using prostate‐specific membrane antigen positron emission tomography and magnetic resonance imaging

Abstract

To identify predictors of early oncological outcomes in patients who opt for robot-assisted laparoscopic radical prostatectomy (RARP) for localized prostate cancer (PCa), including conventional prognostic variables as well as multiparametric magnetic resonance imaging (mpMRI) and prostate-specific membrane antigen (PSMA) positron emission tomography (PET). Patients and MethodsThis observational study included 493 patients who underwent RARP and extended pelvic lymph node dissection (ePLND) for unfavourable intermediate-or high-risk PCa. Outcome measurement was biochemical progression of disease, defined as any postoperative prostate-specific antigen (PSA) value ≥0.2 ng/mL, or the start of additional treatment. Cox regression analysis was performed to assess predictors for biochemical progression, including initial PSA value, biopsy Grade Group (GG), T-stage on mpMRI, and lymph node status on PSMA PET imaging (miN0 vs miN1). ResultsThe median (interquartile range) total follow-up of all included patients without biochemical progression was 12.6 (7.5-22.7) months. When assessing biochemical progression after surgery, initial PSA value (per doubling; odds ratio [OR] 1.22, 95% confidence interval [CI] 1.07-1.40; P = 0.004), biopsy GG ≥4 vs GG 1-2 (OR 1.83, 95% CI 1.18-2.85; P = 0.007), Tstage on mpMRI (rT3a vs rT2: OR 2.13, 95% CI 1.39-3.27; P = 0.001; ≥rT3b vs rT2: OR 4.78, 95% CI 3.20-7.16; P < 0.001) and miN1 on PSMA PET imaging (OR 2.94, 95% CI 2.02-4.27; P < 0.001) were independent predictors of early biochemical progression of disease. ConclusionInitial PSA value, biopsy GG ≥4, ≥rT3 disease on mpMRI and miN1 disease on PSMA PET were predictors of early biochemical progression after RARP. Identifying these patients with an increased risk of early biochemical progression after surgery may have major implications for patient counselling in radical treatment decisions and on patient selection for modern (neo-)adjuvant and systematic treatments.

The prognostic value of lymph node staging with prostate‐specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) and extended pelvic lymph node dissection in node‐positive patients with prostate cancer

“…In addition, assessing regional lymph node metastatic disease, our group recently showed that preoperative models for the prediction of lymph node metastases significantly improved by including findings on PSMA PET [33]. Moreover, multiple studies demonstrated that miN1 on staging PSMA PET is associated with impaired oncological outcomes in all patients undergoing RARP and ePLND [34][35][36][37]. Thus, although PSMA PET/CT only has a moderate sensitivity for the detection of pelvic lymph node metastases [38,39], probably missing lymph nodes smaller than 4 mm, PSMA PET/CT seems to be able to select patients preoperatively in whom (neo)adjuvant treatment may be beneficial.…”

Standardised uptake values as determined on prostate‐specific membrane antigen positron emission tomography/computed tomography is associated with oncological outcomes in patients with prostate cancer

“…Along with RARP, an extended pelvic lymph node dissection (ePLND) is usually indicated for patients with intermediate-and high-risk disease stage, as a staging method for lymph node (LN) involvement [2]. The most common prognostic variables to predict the outcome of patients with PCa after treatment include the PSA level at the time of diagnosis, the biopsy International Society of Urological Pathology (bISUP) score, the percentage of positive biopsies, and the clinical tumour stage [2][3][4]. These variables have prognostic ability on a group level but not for the individual patient [5,6].…”

Integrating magnetic resonance imaging and prostate‐specific membrane antigen positron emission tomography/computed tomography results into prostate cancer treatment decision making

“…One such study was recently published in the BJU International: Dutch researchers investigated the association between preoperative staging with MRI plus prostate-specific membrane antigen (PSMA) positron emission tomography (PET)/CT and short-term oncological outcomes after robotassisted radical prostatectomy with extended lymph node dissection in 493 men with unfavourable intermediate-to very high-risk prostate cancer [1]. In multivariable analysis, seminal vesicle invasion on MRI (radiological [r]T3b, 18% of the patients) and of lymph node metastasis on PSMA PET/ CT (molecular imaging [mi]N1, 13% of the patients) were the only variables significantly associated with a postoperative PSA level of ≥0.1 ng/mL (16% of the patients).…”

“…The study by Meijer et al [1] adds to a growing body of evidence that local staging of prostate cancer with MRI is clinically important, particularly when seminal vesicle invasion is found [2][3][4]. The current TNM classification is clearly at odds with this evidence as it states that MRI findings should not be used for local (T) staging [5].…”

“…Most likely, the presence or absence of obvious extra-prostatic extension or seminal vesicle invasion on MRI is more strongly associated with oncological treatment outcomes than local stage assessed by DRE alone. The next time the TNM classification is revised, the committee will have to consider results from studies like the one by Meijer et al [1]. My guess is that they will then conclude that MRI results should be included in the clinical T-stage categorisation in the next version of the TNM classification.…”