Quantifying downstream impact of inappropriate staging imaging in a cohort of veterans with low- and intermediate-risk incident prostate cancer

INTRODUCTION

According to current National Comprehensive Cancer Network guidelines, routine imagining for staging low-risk prostate cancer is not recommended. However, extensive overuse of guideline-discordant imaging continues to persist. Incidental findings are common on imaging and little is known about the optimal management. Rates of incidental findings vs. false positive diagnosis from inappropriate imaging are poorly understood and have yet to be quantified for low- and intermediate-risk prostate cancer patients.

OBJECTIVE

To determine the frequency of positive radiologic findings in patients with low- and intermediate-risk prostate cancer during initial staging at VA New York Harbor Healthcare System.

METHODS

We retrospectively reviewed all low- and intermediate-risk prostate cancer patients' medical records from the VA New York Harbor Healthcare System for diagnosis from 2005 to 2015. We reviewed each individual's prebiopsy prostate specific antigen (PSA), Gleason score, and clinical stage. We also determined if imaging obtained yielded a false positive, incidental finding, or if metastatic disease occurred within the 6 months following initial diagnosis.

RESULTS

There were 414 men, who were classified as low- to intermediate-risk prostate cancer and underwent inappropriate staging imaging of 4,306 men diagnosed with prostate cancer. Of these 414 men, 178 (43%) had additional follow-up imaging for positive findings. We calculated an incidental finding rate of 10% and a false positive rate of 38% for patients. Five (1%) patients had metastatic disease.

CONCLUSION

Despite guideline recommendations, imaging overuse remains an issue for low-intermediate-risk prostate cancer patients. The false positive rate found in this analysis is alarmingly high at 38%. This use of scans is burdensome to the healthcare system and patient. This study highlights the frequency of inappropriate imaging and its negative consequences.

Health state utilities among contemporary prostate cancer patients on active surveillance

Background

Active surveillance (AS) is the most rapidly expanding management option for favorable-risk prostate cancer (PCa). Early studies suggested substantial decrements in utility (quality of life weights) from disease-related anxiety. Our objective was to determine utilities for contemporary AS patients using different instruments.

Methods

We performed a systematic review of PubMed, PMC and OVID for utility measurements in modern AS patients. We then examined utilities among 37 men on AS participating in focus groups between 2015–2016 using the generic EurQol five dimensions questionnaire (EQ-5D-3L) and Patient Oriented Prostate Utility Scale (PORPUS), a PCa-specific instrument.

Results

The systematic review found previous studies with utilities for PCa treatment and historical watchful waiting populations, but none specifically in contemporary AS. In our AS population, the mean EQ-5D-3L score was 0.90±0.16 (median, 1.00; range, 0.21–1.00) and PORPUS was 0.98±0.03 (median, 0.99; range, 0.84–1.00). The Spearman correlation between the EQ-5D-3L and PORPUS was 0.87 (P<0.0001), and 38% of patients had a difference >0.1 between instruments.

Conclusions

Most contemporary AS patients had high utility scores suggesting that they perceive themselves in good health without a major decrement in quality of life from the disease. However, some patients had substantial differences in utility measured with generic versus disease-specific instruments. Further study is warranted into the optimal instrument for utility assessment in contemporary AS patients.

Informational needs during active surveillance for prostate cancer: A qualitative study

OBJECTIVE

To understand the informational needs during active surveillance (AS) for prostate cancer from the perspectives of patients and providers.

METHODS

We conducted seven focus groups with 37 AS patients in two urban clinical settings, and 24 semi-structured interviews with a national sample of providers. Transcripts were analyzed using applied thematic analysis, and themes were organized using descriptive matrix analyses.

RESULTS

We identified six themes related to informational needs during AS: 1) more information on prostate cancer (biopsy features, prognosis), 2) more information on active surveillance (difference from watchful waiting, testing protocol), 3) more information on alternative management options (complementary medicine, lifestyle modification), 4) greater variety of resources (multiple formats, targeting different audiences), 5) more social support and interaction, and 6) verified integrity of information (trusted, multidisciplinary and secure).

CONCLUSIONS

Patients and providers described numerous drawbacks to existing prostate cancer resources and a variety of unmet needs including information on prognosis, AS testing protocols, and lifestyle modification. They also expressed a need for different types of resources, including interaction and unbiased information.

PRACTICAL IMPLICATIONS

These results are useful to inform the design of future resources for men undergoing AS.

Uptake of Active Surveillance for Very-Low-Risk Prostate Cancer in Sweden

IMPORTANCE

Active surveillance is an important option to reduce prostate cancer overtreatment, but it remains underutilized in many countries. Models from the United States show that greater use of active surveillance is important for prostate cancer screening to be cost-effective.

OBJECTIVES

To perform an up-to-date, nationwide, population-based study on use of active surveillance for localized prostate cancer in Sweden.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study in the National Prostate Cancer Register (NPCR) of Sweden from 2009 through 2014. The NPCR has data on 98% of prostate cancers diagnosed in Sweden and has comprehensive linkages to other nationwide databases. Overall, 32 518 men with a median age of 67 years were diagnosed with favorable-risk prostate cancer, including 4693, 15 403, and 17 115 men with very-low-risk (subset of the low-risk group) (clinical stage, T1c; Gleason score, ≤6; prostate-specific antigen [PSA], <10 ng/mL; PSA density <0.15 ng/mL/cm3; and <8-mm total cancer length in ≤4 positive biopsy cores), low-risk (including all men in the very-low-risk group) (T1-T2; Gleason score, ≤6; and PSA, <10 ng/mL), and intermediate-risk disease (T1-T2 with Gleason score, 7 and/or PSA, 10-20 ng/mL).

EXPOSURES

Diagnosis with favorable-risk prostate cancer.

MAIN OUTCOMES AND MEASURES

Utilization of active surveillance.

RESULTS

The use of active surveillance increased in men of all ages from 57% (380 of 665) to 91% (939 of 1027) for very-low-risk prostate cancer and from 40% (1159 of 2895) to 74% (1951 of 2644) for low-risk prostate cancer, with the strongest increase occurring from 2011 onward. Among men aged 50 to 59 years, 88% (211 of 240) with very-low-risk and 68% (351 of 518) with low-risk disease chose active surveillance in 2014. Use of active surveillance for intermediate-risk disease remained lower, 19% (561 of 3030) in 2014.

CONCLUSIONS AND RELEVANCE

Active surveillance has become the dominant management for low-risk prostate cancer among men in Sweden, with the highest rates yet reported and almost complete uptake for very-low-risk cancer. These data should serve as a benchmark to compare the use of active surveillance for favorable-risk disease around the world.

Qualitative study on decision-making by prostate cancer physicians during active surveillance

OBJECTIVE

To explore and identify factors that influence physicians' decisions while monitoring patients with prostate cancer on active surveillance (AS).

SUBJECTS AND METHODS

A purposive sampling strategy was used to identify physicians treating prostate cancer from diverse clinical backgrounds and geographic areas across the USA. We conducted 24 in-depth interviews from July to December 2015, until thematic saturation was reached. The Applied Thematic Analysis framework was used to guide data collection and analysis. Interview transcripts were reviewed and coded independently by two researchers. Matrix analysis and NVivo software were used for organization and further analysis.

RESULTS

Eight key themes emerged to explain variation in AS monitoring: (i) physician comfort with AS; (ii) protocol selection; (iii) beliefs about the utility and quality of testing; (iv) years of experience and exposure to AS during training; (v) concerns about inflicting 'harm'; (vi) patient characteristics; (vii) patient preferences; and (viii) financial incentives.

CONCLUSION

These qualitative data reveal which factors influence physicians who manage patients on AS. There is tension between providing standardized care while also considering individual patients' needs and health status. Additional education on AS is needed during urology training and continuing medical education. Future research is needed to empirically understand whether any specific protocol is superior to tailored, individualized care.

A qualitative study to understand guideline-discordant use of imaging to stage incident prostate cancer

Background

Approximately half of veterans with low-risk prostate cancer receive guideline-discordant imaging. Our objective was to identify and describe (1) physician knowledge, attitudes, and practices related to the use of imaging to stage prostate cancer, (2) patient attitudes and behaviors related to use of imaging, and (3) to compare responses across three VA medical centers (VAMCs).

Methods

A qualitative approach was used to explore patient and provider knowledge and behaviors relating to the use of imaging. We conducted 39 semi-structured interviews total—including 22 interviews with patients with newly diagnosed with prostate cancer and 17 interviews with physicians caring for them—between September 2014 and July 2015 at three VAMCs representing a spectrum of inappropriate imaging rates. After core theoretical concepts were identified, the Theoretical Domains Framework (TDF) was selected to explore linkages between themes within the dataset and existing domains within the framework. Interviews were audio-recorded, transcribed verbatim, and then coded and analyzed using Nvivo software.

Results

Themes from patient interviews were categorized within four TDF domains. Patients reported little interest in staging as compared to disease treatment (goals), and many could not remember if they had imaging at all (knowledge). Patients tended to trust their doctor to make decisions about appropriate tests (beliefs about capabilities). Some patients expressed a minor concern for radiation exposure, but anxiety about cancer outcomes outweighed these fears (emotion). Themes from physician interviews were categorized within five TDF domains. Most physicians self-reported that they know and trust imaging guidelines (knowledge) yet some were still likely to follow their own intuition, whether due to clinical suspicion or years of experience (beliefs about capabilities). Additionally, physicians reported that medico-legal concerns, fear of missing associated diagnoses (beliefs about consequences), influence from colleagues who image frequently (social influences), and the facility where they practice influences rates of imaging (environmental context).

Conclusions

Interviews with patients and physicians suggest that physicians are the primary (and in some cases only) decision-makers regarding staging imaging for prostate cancer. This finding suggests a physician-targeted intervention may be the most effective strategy to improve guideline-concordant prostate cancer imaging.

Photoreduction of Pyridine Nucleotide by Subcellular Preparations from Rhodopseudomonas spheroides

We have investigated the photoreduction of pyridine nucleotides by crude extracts and chromatophores of Rhodopseudomonas spheroides.Our findings are as follows:NADP is preferentially photoreduced by crude extracts (37,000 x g supernatant fraction) and there is no requirement for the addition of exogenous substrates. Crude extracts also catalyze a nonphotosensitive reduction of NAD.NADP photoreduction is completely inhibited if an NADH trapping system is present and indicates that NADH is required for NADP photoreduction.Washed chromatophores (150,000 x g pellet) do not catalyze NADP photoreduction unless the supernatant fraction is added. The restoring effect of supernatant fraction is lost upon boiling and dialysis. However, supernatant materials can be replaced by an NADH generating system. There is no requirement for anaerobic conditions.Evidence has been presented which suggests that Rhodopseudomonas spheroides contains an energy-linked transhydrogenase that can be driven by a high energy intermediate generated by light or ATP. This intermediate may also be functional in ATP synthesis. The synthesis of ATP and the ATP-supported transhydrogenase is inhibited by oligomycin. This inhibitor does not affect the light-mediated reaction.