A nomogram to predict the absence of clinically significant prostate cancer in males with negative MRI

PURPOSE

To create a nomogram to predict the absence of clinically significant prostate cancer (CSPCa) in males with non-suspicion multiparametric magnetic resonance imaging (mpMRI) undergoing prostate biopsy (PBx).

MATERIALS AND METHODS

We identified consecutive patients who underwent 3T mpMRI followed by PBx for suspicion of PCa or surveillance follow-up. All patients had Prostate Imaging Reporting and Data System score 1-2 (negative mpMRI). CSPCa was defined as Grade Group ≥2. Multivariate logistic regression analysis was performed via backward elimination. Discrimination was evaluated with area under the receiver operating characteristic (AUROC). Internal validation with 1,000x bootstrapping for estimating the optimism corrected AUROC.

RESULTS

Total 327 patients met inclusion criteria. The median (IQR) age and PSA density (PSAD) were 64 years (58-70) and 0.10 ng/mL2 (0.07-0.15), respectively. Biopsy history was as follows: 117 (36%) males were PBx-naive, 130 (40%) had previous negative PBx and 80 (24%) had previous positive PBx. The majority were White (65%); 6% of males self-reported Black. Overall, 44 (13%) patients were diagnosed with CSPCa on PBx. Black race, history of previous negative PBx and PSAD ≥0.15ng/mL2 were independent predictors for CSPCa on PBx and were included in the nomogram. The AUROC of the nomogram was 0.78 and the optimism corrected AUROC was 0.75.

CONCLUSIONS

Our nomogram facilitates evaluating individual probability of CSPCa on PBx in males with PIRADS 1-2 mpMRI and may be used to identify those in whom PBx may be safely avoided. Black males have increased risk of CSPCa on PBx, even in the setting of PIRADS 1-2 mpMRI.

Hemigland Cryoablation of Localized Low, Intermediate and High Risk Prostate Cancer: Oncologic and Functional Outcomes at 5 Years

PURPOSE

We evaluated 5-year oncologic and functional outcomes of hemigland cryoablation of localized prostate cancer.

MATERIALS AND METHODS

We reviewed the records of 160 consecutive men who underwent hemigland cryoablation of localized prostate cancer. Recurrent and/or residual clinically significant prostate cancer was defined as Grade Group 2 or greater on followup biopsy. A prostate specific antigen nadir plus 2 ng/ml according to the Phoenix criteria was used to define biochemical failure. Radical treatment was defined as any whole gland therapy. Treatment failure was defined as any radical and/or whole gland treatment, systemic therapy initiation, metastasis or prostate cancer specific mortality. The study primary end point was treatment failure-free survival. The secondary end points were survival free of biochemical failure, clinically significant prostate cancer and radical treatment. Followup biopsy and functional outcomes were also evaluated. Statistical analysis included the Kaplan-Meier method, and univariate and multivariable Cox and logistic regression with significance considered at p <0.05.

RESULTS

Median patient age was 67 years, baseline prostate specific antigen was 6.3 ng/ml and followup was 40 months. A total of 131 patients (82%) had D'Amico intermediate (66%) or high risk (16%) prostate cancer. At 5 years the treatment failure-free survival rate was 85%, the biochemical failure-free survival rate was 62% and the survival rate free of clinically significant prostate cancer was 89%. Higher baseline prostate specific antigen independently predicted treatment failure (p <0.001), biochemical failure (p=0.048), recurrence and radical treatment (p <0.01). Grade Group 3 or greater independently predicted treatment failure (p=0.04). The metastasis-free survival rate was 100% at 5 years. Pad-free continence and potency (erections sufficient for intercourse) were retained in 97% and 73% of patients, respectively. There was no rectal fistula or mortality.

CONCLUSIONS

Hemigland cryoablation of localized prostate cancer provides effective midterm oncologic outcomes with good continence and potency. Patients with higher baseline prostate specific antigen are at increased risk for biochemical failure, recurrent cancer and treatment failure.

Less nephrotoxicity of paclitaxel and ifosfamide plus nedaplatin for refractory or relapsed germ cell tumors in patients with impaired renal function

OBJECTIVES

To determine the safety and efficacy of the combined regimen of paclitaxel and ifosfamide plus nedaplatin for patients with refractory or relapsed germ cell tumors and impaired renal function.

METHODS

Of a total of 68 patients who received paclitaxel, ifosfamide and nedaplatin chemotherapy for germ cell tumors, those with an estimated glomerular filtration rate <60 mL/min/1.73 m² before paclitaxel, ifosfamide and nedaplatin treatment were defined as having renal dysfunction. The combination chemotherapy regimen included paclitaxel (210 mg/m² on day 1) and ifosfamide (1.2 g/m² on days 2-6) with nedaplatin (100 mg/m² on day 2) on a 3-week cycle.

RESULTS

A total of 10 patients had renal dysfunction with a median estimated glomerular filtration rate of 49.97 mg/mL/1.73 m² (range 31.7-57.5 mg/mL/1.73 m² ). Paclitaxel, ifosfamide and nedaplatin chemotherapy was given as second-line therapy in four patients, third-line in four and fourth-line or later in two. Patients with impaired renal function received pretreatment of a median of 5.5 cycles of platinum-based chemotherapy (range 3-11 cycles) with a median cisplatin dose of 550 mg/m² . The patients were given two to six cycles of paclitaxel, ifosfamide and nedaplatin chemotherapy with no dose reduction, with an overall response rate of 60%. Chemotherapy-induced kidney dysfunction was not observed in any patient with decreased renal function. Furthermore, there was no difference in the frequency of adverse events between patients with renal dysfunction (estimated glomerular filtration rate <60 mL/min/1.73 m² ) and those with normal renal function (estimated glomerular filtration rate ≥60 mL/min/1.73 m² ).

CONCLUSIONS

Paclitaxel, ifosfamide and nedaplatin chemotherapy can be considered a safe and effective regimen that results in less nephrotoxicity in germ cell tumor patients with renal dysfunction.

Step-by-Step: Fusion-guided prostate biopsy in the diagnosis and surveillance of prostate cancer

Objective:

To provide a step-by-step technique for fusion-guided biopsy for prostate cancer diagnosis and surveillance.

Materials and Methods:

All men with clinical indications for image-guided biopsy undergo 3-Tesla multiparametric magnetic resonance imaging (mpMRI) first. Lesions identified on mpMRI are graded using the Prostate Imaging-Reporting and Data System version 2.0 (PI-RADS v2) grading system. At the time of biopsy, real-time 3-dimensional (3D) transrectal ultrasound (TRUS) imaging is acquired and elastically fused with the mpMRI. Both targeted biopsies of MRI-derived suspicious lesions (PI-RADS 3-5) and systematic 12-core biopsies are performed. Patients without suspicious lesion on mpMRI undergo 3D TRUS-guided biopsy in standard templated fashion. In men placed on active surveillance (AS), prior positive sites are revisited using the trajectory and tracking functions of the fusion biopsy software.

Results:

The advantages of MRI/TRUS fusion biopsy for prostate cancer diagnosis and surveillance are numerous. The 3D model created by elastic fusion of real-time TRUS imaging to mpMRI provides excellent visualization of prostate anatomy. Suspicious lesions on mpMRI can be accurately targeted, increasing detection of clinically significant prostate cancer. Biopsy trajectory visualization provides spatial localization of the trajectory of the cores within the prostate. Systematic biopsies are also taken in addition to targeted cores to minimize the effect of the mpMRI-invisible lesion. Prior positive biopsy sites can be tracked in men on AS.

Conclusions:

Combined, the added benefits of prior lesion identification, adequate mapping of prostate anatomy and suspicious lesions, biopsy-trajectory visualization, tracking of prior positive biopsy sites, and combined targeted and systematic cores may offer the most effective method for prostate cancer diagnosis and surveillance.

Contrast-Enhanced Transrectal Ultrasound for Follow-up After Focal HIFU Ablation for Prostate Cancer

The optimal strategy for imaging after focal therapy for prostate cancer is evolving. This series is an initial report on the use of contrast-enhanced transrectal ultrasound (TRUS) in follow-up of patients after high-intensity focused ultrasound (HIFU) hemiablation for prostate cancer. In 7 patients who underwent HIFU hemiablation, contrast-enhanced TRUS findings were as follows: (1) contrast-enhanced TRUS clearly showed the HIFU ablation defect as a sharply marginated nonenhancing zone in all patients; (2) contrast-enhanced TRUS identified suspicious foci of recurrent enhancement within the ablation zone in 2 patients, facilitating image-guided prostate biopsy, which showed prostate cancer; and (3) contrast-enhanced TRUS findings correlated with multiparametric magnetic resonance imaging and biopsy histologic findings.

Which Patients with Negative Magnetic Resonance Imaging Can Safely Avoid Biopsy for Prostate Cancer?

PURPOSE

We sought to determine whether there is a subset of men who can avoid prostate biopsy based on multiparametric magnetic resonance imaging and clinical characteristics.

MATERIALS AND METHODS

Of 1,149 consecutive men who underwent prostate biopsy from October 2011 to March 2017, 135 had prebiopsy negative multiparametric magnetic resonance imaging with PI-RADS™ (Prostate Imaging Reporting and Data System) score less than 3. The detection rate of clinically significant prostate cancer was evaluated according to prostate specific antigen density and prior biopsy history. Clinically significant prostate cancer was defined as Grade Group 2 or greater. Multivariable logistic regression analysis was performed to identify predictors of nonclinically significant prostate cancer on biopsy.

RESULTS

The prostate cancer and clinically significant prostate cancer detection rates were 38% and 18%, respectively. Men with biopsy detected, clinically significant prostate cancer had a smaller prostate (p = 0.004), higher prostate specific antigen density (p = 0.02) and no history of prior negative biopsy (p = 0.01) compared to the nonclinically significant prostate cancer cohort. Prostate specific antigen density less than 0.15 ng/ml/cc (p <0.001) and prior negative biopsy (p = 0.005) were independent predictors of absent clinically significant prostate cancer on biopsy. The negative predictive value of multiparametric magnetic resonance imaging for biopsy detection of clinically significant prostate cancer improved with decreasing prostate specific antigen density, primarily in men with prior negative biopsy (p = 0.001) but not in biopsy naïve men. Of the men 32% had the combination of negative multiparametric magnetic resonance imaging, prostate specific antigen density less than 0.15 ng/ml/cc and negative prior biopsy, and none had clinically significant prostate cancer on repeat biopsy. The incidence of biopsy identified, clinically significant prostate cancer was 18%, 10% and 0% in men with negative multiparametric magnetic resonance imaging only, men with negative multiparametric magnetic resonance imaging and prostate specific antigen density less than 0.15 ng/ml/cc, and men with negative multiparametric magnetic resonance imaging, prostate specific antigen density less than 0.15 ng/ml/cc and negative prior biopsy, respectively.

CONCLUSIONS

We propose that a subset of men with negative multiparametric magnetic resonance imaging, prostate specific antigen density less than 0.15 ng/ml/cc and prior negative biopsy may safely avoid rebiopsy. Conversely prostate biopsy should be considered in biopsy naïve men regardless of negative multiparametric magnetic resonance imaging, particularly those with prostate specific antigen density greater than 0.15 ng/ml/cc.

Primary Whole-gland Cryoablation for Prostate Cancer: Biochemical Failure and Clinical Recurrence at 5.6 Years of Follow-up

We retrospectively evaluated complications and functional and oncologic outcomes of 94 consecutive men who underwent primary whole-gland cryoablation for localized prostate cancer (PCa) from 2002 to 2012. Kaplan-Meier and multivariable Cox regression analyses were performed using a landmark starting at 6 mo of follow-up. In total, 75% patients had D'Amico intermediate- (48%) or high- (27%) risk PCa. Median follow-up was 5.6 yr. Median time to prostate-specific antigen (PSA) nadir was 3.3 mo, and 70 patients reached PSA <0.2ng/ml postcryoablation. The 90-d high-grade (Clavien Grade IIIa) complication rate was 3%, with no rectal fistulas reported. Continence and potency rates were 96% and 11%, respectively. The 5-yr biochemical failure-free survival (PSA nadir+2ng/ml) was 81% overall and 89% for low-, 78% for intermediate-, and 80% for high-risk PCa (p=0.46). The median follow-up was 5.6 and 5.1 yr for patients without biochemical failure and with biochemical failure, respectively. The 5-yr clinical recurrence-free survival was 83% overall and 94% for low-, 84% for intermediate-, and 69% for high-risk PCa (p=0.046). Failure to reach PSA nadir <0.2ng/ml within 6 mo postcryoablation was an independent predictor for biochemical failure (p=0.006) and clinical recurrence (p=0.03). The 5-yr metastases-free survival was 95%. Main limitation is retrospective evaluation. Primary whole-gland cryoablation for PCa provides acceptable medium-term oncologic outcomes and could be an alternative for radiation therapy or radical prostatectomy. PATIENT SUMMARY: Cryoablation is a safe, minimally-invasive procedure that uses cold temperatures delivered via probes through the skin to kill prostate cancer (PCa) cells. Whole-gland cryoablation may offer an alternative treatment option to surgery and radiotherapy. We found that patients had good cancer outcomes 5 yr after whole-gland cryoablation, and those with a prostate-specific antigen value ≥0.2ng/ml within 6 mo after treatment were more likely to have PCa recurrence.

Therapy-related acute myeloid leukemia and myelodysplastic syndrome among refractory germ cell tumor patients

OBJECTIVES

To analyze cases of therapy-related acute myeloid leukemia and myelodysplastic syndrome diagnosed after chemotherapy for refractory testicular and extragonadal germ cell tumor in our experience.

METHODS

A total of 171 consecutive patients who were diagnosed and treated as refractory germ cell tumor and had records of detailed chemotherapy doses between April 1998 and December 2015 were retrospectively reviewed.

RESULTS

Four testicular tumor patients (4/171, 2.3%) developed therapy-related acute myeloid leukemia and myelodysplastic syndrome. Three of them were affected after complete remission of the primary testicular tumor. A median time interval from a start of chemotherapy to a secondary tumor development was 6.8 years (range 3.7-11.5 years). The median total dose of etoposide, ifosfamide, cisplatin and nedaplatin were 3640 mg/m² (range 2906-4000 mg/m² ), 42.7 g (range 19.5-54.0 g), 1100 mg/m² (range 600-1500 mg/m² ) and 500 mg/m² (range 300-1600 mg/m² ), respectively. Etoposide had the only significant relationship between a cumulative dose and leukemogenesis in univariate analysis (P < 0.05). One patient had complete remission, but the other three patients died.

CONCLUSIONS

The present findings show that refractory germ cell tumor patients have an increased risk of therapy-related acute myeloid leukemia and myelodysplastic syndrome. A cumulative dose of etoposide is a significant risk of leukemogenesis. As therapy-related acute myeloid leukemia and myelodysplastic syndrome has a poor prognosis, close follow up is required for refractory germ cell tumor patients.

Diagnostic accuracy of a five-point Likert scoring system for magnetic resonance imaging (MRI) evaluated according to results of MRI/ultrasonography image-fusion targeted biopsy of the prostate

OBJECTIVE

To evaluate the accuracy of a magnetic resonance imaging (MRI)-based Likert scoring system in the detection of clinically significant prostate cancer (CSPC), using MRI/ultrasonography (US) image-fusion targeted biopsy (FTB) as a reference standard.

PATIENTS AND METHODS

We retrospectively reviewed 1218 MRI-detected lesions in 629 patients who underwent subsequent MRI/US FTB between October 2012 and August 2015. 3-Tesla MRI was independently reported by one of eight radiologists with varying levels of experience and scored on a five-point Likert scale. All lesions with Likert scores 1-5 were prospectively defined as targets for MRI/US FTB. CSPC was defined as Gleason score ≥7.

RESULTS

The median patient age was 64 years, PSA level 6.97 ng/mL and estimated prostate volume 52.2 mL. Of 1218 lesions, 48% (n = 581) were rated as Likert 1-2, 35% (n = 428) were Likert 3 and 17% (n = 209) were Likert 4-5. For Likert scores 1-5, the overall cancer detection rates were 12%, 13%, 22%, 50% and 59%, respectively, and the CSPC detection rates were 4%, 4%, 12%, 33% and 48%, respectively. Grading using the five-point scale showed strong positive correlation with overall cancer detection rate (r = 0.949, P = 0.05) and CSPC detection rate (r = 0.944, P = 0.05). By comparison, in Likert 4-5 lesions, significant differences were noted in overall cancer detection rate (63% vs 35%; P = 0.001) and CSPC detection rate (47% vs 29%; P = 0.027) for the more experienced vs the less experienced radiologists.

CONCLUSIONS

The detection rates of overall cancer and CSPC strongly correlated with the five-point grading of the Likert scale. Among radiologists with different levels of experience, there were significant differences in these cancer detection rates.

Morphometric analysis of prostate zonal anatomy using magnetic resonance imaging: impact on age-related changes in patients in Japan and the USA

OBJECTIVES

To evaluate the impact of morphometric magnetic resonance imaging (MRI) analysis of the prostate zonal anatomy on aging, prostatic hypertrophy and lower urinary tract symptoms in patients from Japan and the USA.

SUBJECTS AND METHODS

A retrospective analysis of 307 men, including 156 men from Japan and 151 from the USA, who consecutively underwent 3-Tesla MRI and International Prostate Symptom Score (IPSS) assessment because of elevated PSA levels. Using Synapse-Vincent (Fujifilm), the prostatic zones were segmented in each axial step-section of the T2-weighted MRI to reconstruct a three-dimensional model of the prostate, which was used to calculate: zonal volumes (whole-gland prostate, transition zone and peripheral zone volumes); the presumed circle area ratio (PCAR); and PZ thickness. Bivariate associations were quantified using Spearman's rank correlation coefficients.

RESULTS

The USA subgroup had a greater prostate volume (49 vs 42 mL; P = 0.003) and TZ volume (26 vs 20 mL; P < 0.001) than the Japan subgroup, with no difference in PZ volume (19 vs 20 mL; P = 0.2). There was no age-related increase in PZ volume in either of the subgroups or in the entire cohort (P = 0.9, P = 0.2, P = 0.3, respectively). PZ thickness had a significant negative correlation with PCAR (P < 0.001) and TZ volume (P < 0.001). The greater the increase in the TZ volume with the increase in PCAR, which probably correlates with obstructive pressure, the thinner the PZ became. PCAR had a significant positive correlation with IPSS (P = 0.003) and obstructive symptoms (P = 0.007), while PZ thickness had a significant negative correlation (P = 0.018).

CONCLUSIONS

No age-related increases and no differences between the Japanese and the US subgroups were found with regard to PZ volume. The more TZ volume increased, the higher the obstructive pressure and the thinner the PZ became; these changes were associated with increased obstructive symptoms. MRI analysis of prostate zonal anatomy enhanced our understanding of age-related changes in morphology and urinary symptoms.