Clinically Localized Prostate Cancer: AUA/ASTRO/SUO Guideline. Part I: Risk Stratification, Shared Decision Making, and Care Options

Recommendations of Active Surveillance for Intermediate-risk Prostate Cancer: Results from a National Survey of Radiation Oncologists and Urologists

BACKGROUND

While active surveillance (AS) for intermediate-risk prostate cancer (PCa) remains controversial, perceptions of AS and treatment recommendations among PCa specialists are largely unknown. Thus, we performed a national survey of radiation oncologists (ROs) and urologists (UROs) to elicit attitudes and AS recommendations for intermediate-risk PCa.

OBJECTIVE

To determine whether AS for PCa is becoming readily accepted by PCa specialists in the USA.

DESIGN, SETTING, AND PARTICIPANTS

From January to July 2017, we conducted a national survey of 915 ROs and 940 UROs on perceptions of AS and its use among patients with intermediate-risk PCa.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Perceived effectiveness and comfort with AS and recommendation of AS from case presentations represented the primary outcomes. Pearson chi-square and multivariable logistic regression analyses were used to identify physician characteristics associated with primary outcomes.

RESULTS AND LIMITATIONS

Overall, the response rate was 37.3% (n=692) and was similar for ROs and UROs (35.7% vs 38.7%; p=0.18). For intermediate-risk PCa, both UROs and ROs expressed limited favorable views that AS is effective (39.8% vs 33.0%; p=0.06) and felt comfortable recommending it (37.6% vs 25.9%; p=0.001). From clinical scenarios, both specialties infrequently recommended AS for a healthy patient diagnosed with intermediate-risk PCa. For a healthy 55-yr-old patient with PSA of 8ng/ml and Gleason 3+4 PCa, few ROs and UROs recommended AS (2.8% vs 4.3%; adjusted odds ratio [AOR] 0.42; p=0.12). AS was more likely to be recommended equally by ROs and UROs for a healthy 75-yr-old with the same clinicopathologic characteristics (29.0% vs 35.4%; AOR 0.68; p=0.09). Limitations include a modest response rate for our survey.

CONCLUSIONS

Our national survey revealed that many ROs and UROs do not believe that AS is effective or feel comfortable recommending it or selecting it as an option for younger patients with intermediate-risk PCa.

PATIENT SUMMARY

We performed a national survey of radiation oncologists and urologists to assess attitudes regarding active surveillance (AS) and its use among patients with intermediate-risk prostate cancer. Our study demonstrates that radiation oncologists and urologists are not yet comfortable with recommending AS and rarely endorse its use for younger patients.

Focal therapy for localized prostate cancer: is there a "middle ground" between active surveillance and definitive treatment?

In recent years, it has come a long way in the diagnosis, treatment, and follow-up of prostate cancer. Beside this, it was argued that definitive treatments could cause overtreatment, particularly in the very low, low, and favorable risk group. When alternative treatment and follow-up methods are being considered for this group of patients, active surveillance is seen as a good alternative for patients with very low and low-risk groups in this era. However, it has become necessary to find other alternatives for patients in the favorable risk group or patients who cannot adopt active follow-up. In the light of technological developments, the concept of focal therapy was introduced with the intensification of research to treat only the lesioned area instead of treating the entire organ for prostate lesions though there are not many publications about many of them yet. According to the initial results, it was understood that the results could be good if the appropriate focal therapy technique was applied to the appropriate patient. Thus, focal therapies have begun to find their "middle ground" place between definitive therapies and active follow-up.

Tissue-based multigene expression tests for pretreatment prostate cancer risk assessment: current status and future perspectives

Prostate cancer is a highly prevalent disease with ample spectrum of aggressiveness and treatment options. Low-risk disease can be safely managed by nonintervention strategies, such as active surveillance; however, accurate risk assessment is warranted. Molecular tests have been developed and validated to complement standard clinicopathological parameters and help to improve risk stratification in prostate cancer. Herein, we review selected tissue-based assays, including genomic prostate score, cell cycle progression score and genomic classifier, with particular emphasis on their role in patient risk assessment in a pretreatment setting, in view of their current or potential utilization in active surveillance.

The emerging role of imaging in prostate cancer secondary screening: multiparametric magnetic resonance imaging and the incipient incorporation of molecular imaging

An increasingly robust body of evidence indicates that multiparametric MRI (mpMRI) prior to prostate biopsy can improve the detection of clinically significant prostate cancer while avoiding unnecessary biopsies. As a result, the use of mpMRI and biopsy platforms that allow for the real-time fusion of mpMRI and transrectal ultrasound images is now routinely used in clinical practice. On the horizon, molecular imaging offers the promise of improved sensitivity relative to mpMRI and early data would suggest that the combination of mpMRI and positron emission tomography using radiotracers targeting prostate-specific membrane antigen provide a more accurate assessment than either modality alone. In this review, we examine the current role of imaging to aid in the initial diagnosis of prostate cancer.

Mind the gap: Physicians' assessment of patients' importance weights in localized prostate cancer

BACKGROUND

The management of localized prostate cancer is challenging because of the many therapeutic options available, none of which is generally acknowledged as superior to the others in every respect. The selection of the most appropriate treatment should therefore reflect patients' preferences.

OBJECTIVE

The purpose of the following study was to pilot a new approach for investigating whether urologists who had previously provided patients with therapeutic advice actually knew their patients' importance weights concerning the relevant aspects of the treatments at issue.

METHOD

Participants were patients recently diagnosed with localized prostate cancer (n = 20), urologists (n = 10), and non-medical professionals (architects, n = 10). These last served as a control group for the urologists and were matched to them for age and gender. Patients' importance weights were elicited by two standard methods (Direct Rating and Value Hierarchy). Each urologist was asked to estimate (with Direct Rating) his/her patient's importance weights. The same task was performed by a corresponding architect, who never met the patient and knew only the patient's age. Univariate and bivariate statistical analyses were performed to investigate the association between importance weights as elicited from patients and as estimated by urologists and architects, as well as to assess whether such agreement was attribute-dependent.

RESULTS

Participants found both elicitation methods easy to use. The correlation between patients' actual importance weights and urologists' estimates was poor and comparable to that obtained between patients and architects. This result did not depend on the attribute considered, with the sole exception of the attribute "Effectiveness in curing the cancer", which was evaluated as the most important attribute by the majority of participants.

CONCLUSION

These findings demonstrate the feasibility of the employed methodology and highlight the need to support preference-sensitive decisions in clinical practice by facilitating the elicitation of patients' importance weights, as well as their communication to physicians.

Impact of the SPOP Mutant Subtype on the Interpretation of Clinical Parameters in Prostate Cancer

Purpose

Molecular characterization of prostate cancer, including The Cancer Genome Atlas, has revealed distinct subtypes with underlying genomic alterations. One of these core subtypes, SPOP (speckle-type POZ protein) mutant prostate cancer, has previously only been identifiable via DNA sequencing, which has made the impact on prognosis and routinely used risk stratification parameters unclear.

Methods

We have developed a novel gene expression signature, classifier (Subclass Predictor Based on Transcriptional Data), and decision tree to predict the SPOP mutant subclass from RNA gene expression data and classify common prostate cancer molecular subtypes. We then validated and further interrogated the association of prostate cancer molecular subtypes with pathologic and clinical outcomes in retrospective and prospective cohorts of 8,158 patients.

Results

The subclass predictor based on transcriptional data model showed high sensitivity and specificity in multiple cohorts across both RNA sequencing and microarray gene expression platforms. We predicted approximately 8% to 9% of cases to be SPOP mutant from both retrospective and prospective cohorts. We found that the SPOP mutant subclass was associated with lower frequency of positive margins, extraprostatic extension, and seminal vesicle invasion at prostatectomy; however, SPOP mutant cancers were associated with higher pretreatment serum prostate-specific antigen (PSA). The association between SPOP mutant status and higher PSA level was validated in three independent cohorts. Despite high pretreatment PSA, the SPOP mutant subtype was associated with a favorable prognosis with improved metastasis-free survival, particularly in patients with high-risk preoperative PSA levels.

Conclusion

Using a novel gene expression model and a decision tree algorithm to define prostate cancer molecular subclasses, we found that the SPOP mutant subclass is associated with higher preoperative PSA, less adverse pathologic features, and favorable prognosis. These findings suggest a paradigm in which the interpretation of common risk stratification parameters, particularly PSA, may be influenced by the underlying molecular subtype of prostate cancer.

National Trends in Active Surveillance for Prostate Cancer: Validation of Medicare Claims-based Algorithms

OBJECTIVE

To better describe the real-world use of active surveillance. Active surveillance is a preferred management option for low-risk prostate cancer, yet its use outside of high-volume institutions is poorly understood. We created multiple claims-based algorithms, validated them using a robust clinical registry, and applied them to Medicare claims to describe national utilization.

MATERIALS AND METHODS

We identified men with prostate cancer from 2012-2014 in a 100% sample of Michigan Medicare data and linked them with the Michigan Urologic Surgery Improvement Collaborative (MUSIC) registry. Using MUSIC treatment assignment as the standard, we determined the performance of 8 claims-based algorithms to identify men on active surveillance. We selected 3 algorithms (the most sensitive, the most specific, and a balanced algorithm incorporating age and comorbidity) and applied them to a 20% national Medicare sample to describe national trends.

RESULTS

We identified 1186 men with incident prostate cancer and completely linked data. Eight algorithms were tested with sensitivity ranging from 23.5% to 88.2% and specificity ranging from 93.5% to 99.1%. We found that the use of surveillance for men with incident prostate cancer increased from 2007 to 2014, nationally. However, among all men in the population, there was a large decrease in the rate of prostate cancer diagnosis and an increased or stable rate in the use of active surveillance, depending on the algorithm used. Less than 25% of men on active surveillance underwent a confirmatory prostate biopsy.

CONCLUSION

We describe the performance of claims-based algorithms to identify active surveillance.

A Younger Man With Localized Prostate Cancer Asks, "Which Type of Radiation Is Right for Me?"

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice. A 61-year-old man presents with stage II prostate cancer after a period of active surveillance. Work-up reveals T1cN0M0 carcinoma, a prostate-specific antigen (PSA) level of 4.8 ng/mL, and Grade Group II (highest Gleason 3+4) in three cores of 12 taken, at the right mid-gland and right apex. The patient has been on active surveillance for the past 16 months. He was originally diagnosed after biopsy for an elevated PSA with stage I prostate cancer, T1cN0M0; PSA, 4.5 ng/mL; Grade Group 1 (Gleason 3+3) in one core of 12 taken, also at the right mid-gland. A multiparametric magnetic resonance imaging scan showed a heterogeneous peripheral zone without a dominant lesion and a calculated prostate volume of 28 mL. His medical history includes hypercholesterolemia, for which he takes atorvastatin. He is otherwise healthy and has no other significant medical or surgical history. His father had prostate cancer in his 70s and died of other causes at 89 years of age. The patient reports 2- to 3-hour urinary frequency and 0 to 1 nocturia, and has no difficulty obtaining or maintaining an erection. After meeting with his urologist, he sees a radiation oncologist.

Randomized Trial of Partial Gland Ablation with Vascular Targeted Phototherapy versus Active Surveillance for Low Risk Prostate Cancer: Extended Followup and Analyses of Effectiveness

PURPOSE

The prospective PCM301 trial randomized 413 men with low risk prostate cancer to partial gland ablation with vascular targeted photodynamic therapy in 207 and active surveillance in 206. Two-year outcomes were reported previously. We report 4-year rates of intervention with radical therapy and further assess efficacy with biopsy results.

MATERIALS AND METHODS

Prostate biopsies were mandated at 12 and 24 months. Thereafter patients were monitored for radical therapy with periodic biopsies performed according to the standard of care at each institution. Ablation efficacy was assessed by biopsy results overall and in field in the treated lobe or the lobe with index cancer.

RESULTS

Conversion to radical therapy was less likely in the ablation cohort than in the surveillance cohort, including 7% vs 32% at 2 years, 15% vs 44% at 3 years and 24% vs 53% at 4 years (HR 0.31, 95% CI 0.21-0.46). Radical therapy triggers were similar in the 2 arms. Cancer progression rates overall and by grade were significantly lower in the ablation cohort (HR 0.42, 95% CI 0.29-0.59). End of study biopsy results were negative throughout the prostate in 50% of patients after ablation vs 14% after surveillance (risk difference 36%, 95% CI 28-44). Gleason 7 or higher cancer was less likely for ablation than for surveillance (16% vs 41%). Of the in field biopsies 10% contained Gleason 7 cancer after ablation vs 34% after surveillance.

CONCLUSIONS

In this randomized trial of partial ablation of low risk prostate cancer photodynamic therapy significantly reduced the subsequent finding of higher grade cancer on biopsy. Consequently fewer cases were converted to radical therapy, a clinically meaningful benefit that lowered treatment related morbidity.

A Contemporary Prostate Biopsy Risk Calculator Based on Multiple Heterogeneous Cohorts

BACKGROUND

Prostate cancer prediction tools provide quantitative guidance for doctor-patient decision-making regarding biopsy. The widely used online Prostate Cancer Prevention Trial Risk Calculator (PCPTRC) utilized data from the 1990s based on six-core biopsies and outdated grading systems.

OBJECTIVE

We prospectively gathered data from men undergoing prostate biopsy in multiple diverse North American and European institutions participating in the Prostate Biopsy Collaborative Group (PBCG) in order to build a state-of-the-art risk prediction tool.

DESIGN, SETTING, AND PARTICIPANTS

We obtained data from 15 611 men undergoing 16 369 prostate biopsies during 2006-2017 at eight North American institutions for model-building and three European institutions for validation.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We used multinomial logistic regression to estimate the risks of high-grade prostate cancer (Gleason score ≥7) on biopsy based on clinical characteristics, including age, prostate-specific antigen, digital rectal exam, African ancestry, first-degree family history, and prior negative biopsy. We compared the PBCG model to the PCPTRC using internal cross-validation and external validation on the European cohorts.

RESULTS AND LIMITATIONS

Cross-validation on the North American cohorts (5992 biopsies) yielded the PBCG model area under the receiver operating characteristic curve (AUC) as 75.5% (95% confidence interval: 74.2-76.8), a small improvement over the AUC of 72.3% (70.9-73.7) for the PCPTRC (p<0.0001). However, calibration and clinical net benefit were far superior for the PBCG model. Using a risk threshold of 10%, clinical use of the PBCG model would lead to the equivalent of 25 fewer biopsies per 1000 patients without missing any high-grade cancers. Results were similar on external validation on 10 377 European biopsies.

CONCLUSIONS

The PBCG model should be used in place of the PCPTRC for prediction of prostate biopsy outcome.

PATIENT SUMMARY

A contemporary risk tool for outcomes on prostate biopsy based on the routine clinical risk factors is now available for informed decision-making.

VPAC1-targeted PET/CT scan: improved molecular imaging for the diagnosis of prostate cancer using a novel cell surface antigen

PURPOSE

Current approaches to prostate cancer screening and diagnosis are plagued with limitations in diagnostic accuracy. There is a compelling need for biomolecular imaging that will not only detect prostate cancer early but also distinguish prostate cancer from benign lesions accurately. In this topic paper, we review evidence that supports further investigation of VPAC1-targeted PET/CT imaging in the primary diagnosis of prostate cancer.

METHODS

A non-systematic review of Medline/PubMed was performed. English language guidelines on prostate cancer diagnosis and management, original articles, and review articles were selected based on their clinical relevance.

RESULTS

VPAC1 receptors were overexpressed 1000 times more in prostate cancer than benign prostatic stromal tissue. In vitro and in vivo studies showed that Copper-64 labeled analogs of VPAC1 ligands can be synthesized with high radiochemical efficiency and purity. The radioactive probes had excellent VPAC1 receptor binding specificity and affinity. They had good biochemical stability in vitro and in mouse and human serum. They had minimal urinary excretion, which made them favorable for prostate cancer imaging. Initial feasibility study in men with prostate cancer showed that the probes were safe with no reported adverse reaction. 64Cu-TP3805 PET/CT detected 98% of prostate cancer lesions and nodal metastasis as confirmed with whole mount histopathological evaluation.

CONCLUSIONS

VPAC1 receptors are promising targets for biomolecular imaging of primary prostate cancer that can distinguish malignant from benign lesions non-invasively. Further investigations are warranted to validate initial findings and define the clinical utilities of VPAC1-targeted PET imaging for prostate cancer diagnosis and management.

Potential Impact of 68Ga-PSMA-11 PET/CT on the Planning of Definitive Radiation Therapy for Prostate Cancer

Standard-of-care imaging for initial staging of prostate cancer (PCa) underestimates disease burden. Prostate-specific membrane antigen (PSMA) PET/CT detects PCa metastasis with superior accuracy, having a potential impact on the planning of definitive radiation therapy (RT) for nonmetastatic PCa. Our objectives were to determine how often definitive RT planning based on standard target volumes covers ⁶⁸Ga-PSMA-11 PET/CT-defined disease and to assess the potential impact of ⁶⁸Ga-PSMA-11 PET/CT on definitive RT planning. Methods: This was a post hoc analysis of an intention-to-treat population of 73 patients with localized PCa without prior local therapy who underwent ⁶⁸Ga-PSMA PET/CT for initial staging as part of an investigational new drug trial. Eleven of the 73 were intermediate-risk (15%), 33 were high-risk (45%), 22 were very-high-risk (30%), and 7 were N1 (9.5%). Clinical target volumes (CTVs), which included the prostate, seminal vesicles, and (in accord with the Radiation Therapy Oncology Group consensus guidelines) pelvic lymph nodes (LNs), were contoured on the CT portion of the PET/CT images by a radiation oncologist masked to the PET findings. ⁶⁸Ga-PSMA-11 PET/CT images were analyzed by a nuclear medicine physician. ⁶⁸Ga-PSMA-11-positive lesions not covered by planning volumes based on the CTVs were considered to have a major potential impact on treatment planning. Results: All patients had one or more ⁶⁸Ga-PSMA-11-positive primary prostate lesions. Twenty-five (34%) and 7 (9.5%) of the 73 patients had ⁶⁸Ga-PSMA-11-positive pelvic LN and distant metastases, respectively. The sites of LN metastases in decreasing order of frequency were external iliac (20.5%), common iliac (13.5%), internal iliac (12.5%) obturator (12.5%), perirectal (4%), abdominal (4%), upper diaphragm (4%), and presacral (1.5%). The median size of the LN lesions was 6 mm (range, 4-24 mm). RT planning based on the CTVs covered 69 (94.5%) of the 73 primary lesions and 20 (80%) of the 25 pelvic LN lesions, on a per-patient analysis. Conclusion: ⁶⁸Ga-PSMA-11 PET/CT had a major impact on intended definitive RT planning for PCa in 12 (16.5%) of the 73 patients whose RT fields covered the prostate, seminal vesicles, and pelvic LNs and in 25 (37%) of the 66 patients whose RT fields covered the prostate and seminal vesicles but not the pelvic LNs.

Impact of Metabolic Diseases, Drugs, and Dietary Factors on Prostate Cancer Risk, Recurrence, and Survival: A Systematic Review by the European Association of Urology Section of Oncological Urology

CONTEXT

To date, established risk factors for prostate cancer (PCa) are limited to age, race, family history, and certain genetic polymorphisms. Despite great research efforts, available evidence on potentially modifiable risk factors is conflicting. Moreover, most studies on PCa risk factors did not consider the impact of prostate-specific antigen (PSA) testing on PCa diagnosis.

OBJECTIVE

To provide a detailed overview of the latest evidence on the role of metabolic diseases, drugs, and dietary factors for risk of PCa incidence, recurrence, and survival in men exposed to PSA testing.

EVIDENCE ACQUISITION

A systematic review of the English-language literature was performed using the MEDLINE, Cochrane Central Register of Controlled Trials, and Web of Science databases according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses recommendations. Randomized, case-control, or cohort studies published during the periods 2008-2017 (on drugs and metabolic diseases) and 2003-2017 (on dietary factors), with extensive follow-up (≥8-10yr for studies on PCa risk; ≥2-5yr for studies on PCa recurrence, progression, and survival, depending on the review subtopic) and adjusting of the analyses, beyond established risk factors, for either rate of PSA testing (for risk analyses) or PCa stage and primary treatment (for survival analyses), were eligible for inclusion.

EVIDENCE SYNTHESIS

Overall, 39 reports from 22 observational studies were included. Studies were heterogeneous regarding definitions of exposure or outcomes, length of follow-up, risk of bias, and confounding. For some risk factors, evidence was insufficient to assess potential effects, while for others there was no evidence of an effect. For selected risk factors, namely metformin, aspirin and statin use, diabetes, obesity, and specific dietary intakes, there was low-quality evidence of modest effects on PCa risk.

CONCLUSIONS

Current evidence from long-term observational studies evaluating the effect of drugs, metabolic diseases, and dietary factors for PCa risk considering the impact of PSA testing is still not conclusive. Future research is needed to confirm the associations suggested by our review, exploring their potential biological explanations and selecting those risk factors most likely to trigger effective public health interventions.

PATIENT SUMMARY

We reviewed the available studies published in the recent literature on the potential role of drugs, metabolic diseases, and food and dietary factors for the risk of prostate cancer, considering the impact of prostate-specific antigen testing on prostate cancer diagnosis. We found that for some factors data are currently insufficient to make definitive conclusions, while for others available studies seem to indicate an effect on the risk of prostate cancer.

Accuracy of tumor segmentation from multi-parametric prostate MRI and 18F-choline PET/CT for focal prostate cancer therapy applications

BACKGROUND

The study aims to assess the accuracy of multi-parametric prostate MRI (mpMRI) and 18F-choline PET/CT in tumor segmentation for clinically significant prostate cancer. 18F-choline PET/CT and 3 T mpMRI were performed in 10 prospective subjects prior to prostatectomy. All subjects had a single biopsy-confirmed focus of Gleason ≥ 3+4 cancer. Two radiologists (readers 1 and 2) determined tumor boundaries based on in vivo mpMRI sequences, with clinical and pathologic data available. 18F-choline PET data were co-registered to T2-weighted 3D sequences and a semi-automatic segmentation routine was used to define tumor volumes. Registration of whole-mount surgical pathology to in vivo imaging was conducted utilizing two ex vivo prostate specimen MRIs, followed by gross sectioning of the specimens within a custom-made 3D-printed plastic mold. Overlap and similarity coefficients of manual segmentations (seg1, seg2) and 18F-choline-based segmented lesions (seg3) were compared to the pathologic reference standard.

RESULTS

All segmentation methods greatly underestimated the true tumor volumes. Human readers (seg1, seg2) and the PET-based segmentation (seg3) underestimated an average of 79, 80, and 58% of the tumor volumes, respectively. Combining segmentation volumes (union of seg1, seg2, seg3 = seg4) decreased the mean underestimated tumor volume to 42% of the true tumor volume. When using the combined segmentation with 5 mm contour expansion, the mean underestimated tumor volume was significantly reduced to 0.03 ± 0.05 mL (2.04 ± 2.84%). Substantial safety margins up to 11-15 mm were needed to include all tumors when the initial segmentation boundaries were drawn by human readers or the semi-automated 18F-choline segmentation tool. Combining MR-based human segmentations with the metabolic information based on 18F-choline PET reduced the necessary safety margin to a maximum of 9 mm to cover all tumors entirely.

CONCLUSIONS

To improve the outcome of focal therapies for significant prostate cancer, it is imperative to recognize the full extent of the underestimation of tumor volumes by mpMRI. Combining metabolic information from 18F-choline with MRI-based segmentation can improve tumor coverage. However, this approach requires confirmation in further clinical studies.

Long noncoding RNA PVT1 promotes EMT via mediating microRNA-186 targeting of Twist1 in prostate cancer

The pathogenesis and the underlying mechanism of endothelial-mesenchymal transition in prostate cancer remain unclear. Plasmacytoma variant translocation 1 (PVT1), a novel long non-coding RNA maps to 8q24.21, and in many tumor studies the up-regulation of PVT1 has already been reported. PVT1 is closely related to tumor cell proliferation, invasion, and metastasis. In this study, we employed a combination of techniques to study the role of PVT1 in prostate cancer, which included bioinformatic analysis, Western blotting and cell migration assays of prostate cancer cell lines. We report that PVT1 promotes prostate cancer invasion and metastasis by modulating EMT. Furthermore, PVT1 can promote EMT by up-regulation of Twist1, a transcription factor associated with EMT. We then confirmed that PVT1 acts as a sponge for miRNA-186-5p and positively regulates Twist1 by a sponge effect. Therefore, this study has revealed a novel MECHANISM for the promotion of EMT in prostate cancer by PVT1. Our findings suggest that the PVT1/miR-186/Twist1 regulatory axis may be a new therapeutic target for prostate cancer.

Marital status independently predicts prostate cancer survival in men who underwent radical prostatectomy: An analysis of 95,846 individuals

Marital status is an independent prognostic factor for survival in several types of cancer, but has not been fully studied in prostate cancer (PCa). A total of 95,846 men diagnosed with PCa were treated with radical prostatectomy (RP) between 2004 and 2009 within 18 Surveillance, Epidemiology and End Results registries. Survival curves were generated using Kaplan-Meier estimates and differences in survival were assessed using the log-rank test. Cox regression models were used to assess the impact of marital status on survival outcomes. The results demonstrated that the 8-year cancer-cause specific survival (CSS) rate of married men was higher than unmarried individuals. Further analyses revealed that divorced/separated men had a higher proportion of high Gleason scores (GS) PCa at diagnosis [hazard ratio (HR), 1.12; P=0.007] and those patients had the worst survival outcomes independent of age, ethnicity, grade, stage and sequence number [HR, 1.61; 95% confidence interval (CI), 1.34-1.93]. Interestingly, it was observed that CSS among divorced/separated men decreased as the GS increased (GS≤6: HR, 2.5; GS=7: HR, 1.71; GS≥8: HR, 1.50; all P<0.05). Apart from that, no significant differences in CSS were observed in those who had never been married (HR, 1.20) or were widowed (HR, 1.13) relative to the married group. The results of the present study support the hypothesis that marital status is an independent prognostic factor among men with PCa who underwent RP. It was demonstrated that the mortality rates of divorced or separated men with PCa were significantly greater compared with the other groups. A further understanding of the potential associations among marital status, psychosocial factors and survival outcomes may help in developing novel, more effective methods of treating different groups of patients with PCa.

Immunological Aspects of Cryoablation of Non-Small Cell Lung Cancer: A Comprehensive Review

In cryoimmunotherapy, target tumors are treated with cryoablation to generate antitumor immune responses. Because immune checkpoint inhibitors have demonstrated that lung cancer can be an immunotherapy-responsive disease, there has been renewed interest in the immunological aspects of cryoablation of lung cancer. Herein, we review preclinical and clinical trials of cryoablation of primary lung tumors. We examine the magnitude of cryoablation-induced antitumor immune responses and the synergy between cryoablation and either other immunotherapies or molecular targeted therapies to improve treatment responses in advanced lung cancer. We further discuss a rationale for the addition of cryoablation to immune checkpoint inhibitors for the treatment of advanced lung cancer, which is currently under clinical investigation.

Prostate Cancer Markers

Diagnostic biomarkers derived from blood, urine, or prostate tissue provide additional information beyond clinical calculators to determine the risk of detecting high-grade prostate cancer. Once diagnosed, multiple markers leverage prostate cancer biopsy tissue to prognosticate clinical outcomes, including adverse pathology at radical prostatectomy, disease recurrence, and prostate cancer mortality; however the clinical utility of some outcomes to patient decision making is unclear. Markers using tissue from radical prostatectomy specimens provide additional information about the risk of biochemical recurrence, development of metastatic disease, and subsequent mortality beyond existing multivariable clinical calculators (the use of a marker to simply sub-stratify risk groups such as the NCCN groups is of minimal value). No biomarkers currently available for prostate cancer have been prospectively validated to be predict an improved clinical outcome for a specific therapy based on the test result; however, further research and development of these tests may produce a truly predictive biomarker for prostate cancer treatment.

Balancing Confounding and Generalizability Using Observational, Real-world Data: 17-gene Genomic Prostate Score Assay Effect on Active Surveillance

Randomized, controlled trials can provide high-quality, unbiased evidence for therapeutic interventions but are not always a practical or viable study design for certain healthcare decisions, such as those involving prognostic or predictive testing. Studies using large, real-world databases may be more appropriate and more generalizable to the intended target population of physicians and patients to answer these questions but carry potential for hidden bias. We illustrate several emerging methods of analyzing observational studies using propensity score matching (PSM) and coarsened exact matching (CEM). These advanced statistical methods are intended to reveal a "hidden experiment" within an observational database, and so refute or confirm a potential causal effect of assignment to an intervention and study outcome. We applied these methods to the Optum™ Research Database (ORD; Eden Prairie, MN) of electronic health records and administrative claims data to assess the effect of the 17-gene Genomic Prostate Score® (GPS™; Genomic Health, Redwood City, CA) assay on use of active surveillance (AS). In a traditional multivariable logistic regression, the GPS assay increased the use of AS by 29% (95% CI, 24%-33%). Upon applying the matching methods, the effect of the GPS assay on AS use varied between 27% and 80% and the matched data were significant among all algorithms. All matching algorithms performed well in identifying matched data that improved the imbalance in baseline covariates. By using different matching methods to assess causal inference in an observational database, we provide further confidence that the effect of the GPS assay on AS use is statistically significant and unlikely to be a result of confounding due to differences in baseline characteristics of the patients or the settings in which they were seen.