Is one narrative enough? Analytical tools should match the problems they address

2020 ◽  
pp. medethics-2020-106309
Author(s):  
Nathan Hodson ◽  
Susan Bewley

Jeff Nisker describes his personal experience of a diagnosis of advanced prostate cancer and the kindnesses he received from friendly doctors. He claims that this narrative account supports the promotion of Prostate Specific Antigen (PSA) screening for asymptomatic men and impugns statisticians, mistakenly thinking that their opposition to PSA screening derives from concerns about financial cost. The account inadvertently demonstrates the danger of over-reliance on a single ethical tool for critical analysis. In the first part of this response, we describe the statistical evidence. The most reliable Cochrane meta-analyses have not shown that PSA screening saves lives overall. Moreover, the high false positive rate of PSA screening leads to overinvestigation which results in unnecessary anxiety and increased cases of unnecessary sepsis, urinary incontinence and sexual dysfunction. Then we describe how narrative ethics alone is an insufficient tool to make claims about policies, such as PSA screening, which have hidden harms. Although Nisker’s story-telling is compelling and evokes emotions, narrative ethics of this sort have an inherent bias against people who would be harmed by the counterfactual. Particular care must be taken to look for and consider those untellable stories. Ethicists who only consider narratives which are readily at hand risk harming those who are voiceless or protected by the status quo. PSA screening is the wrong tool to reduce prostate cancer deaths and narrative ethics is the wrong tool to appraise this policy. It is vital that the correct theoretical tools are applied to the medical and ethical questions under scrutiny.

1986 ◽  
Vol 1 (2) ◽  
pp. 67-76 ◽  
Author(s):  
Manabu Kuriyama

Prostate-specific antigen (PA) has been evaluated clinically as a tumor marker of prostate cancer with the use of enzyme immunoassay (EIA). For serodetection of prostate cancer, PA was assayed in a total of 1,109 sera. From mean ± 3 S.D. of normal controls, upper cut-off values in males were decided as 2.5 and 1.2 ng/ml in Americans and Japanese, respectively. Serum PA values in prostate cancer patients were positive in 78% of Americans and 62% of Japanese. However, in benign prostatic hypertrophy (BPH) cases, a high false positive rate of 41% was observed in Americans. Simultaneous assays of serum PA and PAP showed high sensitivity and specificity in the detection of prostate cancer. This antigen could be used, as well as PAP, for monitoring prostate cancer patients. Furthermore, serum PA levels prior to treatment may express to some degree the malignant potential of the cancer. These results suggest that PA may be useful as a tumor marker of prostate cancer.


2016 ◽  
Author(s):  
Tyler M. Seibert ◽  
Chun Chieh Fan ◽  
Yunpeng Wang ◽  
Verena Zuber ◽  
Roshan Karunamuni ◽  
...  

AbstractBackgroundProstate-specific-antigen (PSA) screening resulted in reduced prostate cancer (PCa) mortality in a large clinical trial, but due to a high false-positive rate, among other concerns, many guidelines do not endorse universal screening and instead recommend an individualized decision based on each patient’s risk. Genetic risk may provide key information to guide the decisions of whether and at what age to screen an individual man for PCa.MethodsGenotype, PCa status, and age from 34,444 men of European ancestry from the PRACTICAL consortium database were analyzed to select single-nucleotide polymorphisms (SNPs) associated with prostate cancer diagnosis. These SNPs were then incorporated into a survival analysis to estimate their effects on age at PCa diagnosis. The resulting polygenic hazard score (PHS) is an assessment of individual genetic risk. The final model was validated in an independent dataset comprised of 6,417 men with screening PSA and genotype data. PHS was calculated for these men to test for prediction of PCa-free survival. PHS was also combined with age-specific PCa incidence data from the U.S. population to generate a PCa-Risk (PCaR) age that relates a given man’s risk to that of the population average. PHS and PCaR age were evaluated for prediction of positive predictive value (PPV) of PSA screening.FindingsPHS calculated from 54 SNPs was very highly predictive of age at PCa diagnosis for men in the validation set (p =10−53). PPV of PSA screening varied from 0.18 to 0.52 for men with low and high genetic risk, respectively. PHS modulates PCa-free survival curves by an estimated 20 years between men in the 1st or 99th percentiles of genetic risk.InterpretationPolygenic hazard scores give personalized genetic risk estimates and can inform the decisions of whether and at what age to screen a man for PCa.FundingDepartment of Defense #W81XWH-13-1-0391


Biology Open ◽  
2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Morgan Thompson ◽  
Noemi Sarabia Feria ◽  
Ally Yoshioka ◽  
Eugene Tu ◽  
Fehmi Civitci ◽  
...  

ABSTRACT Current methods for non-invasive prostate cancer (PrCa) detection have a high false-positive rate and often result in unnecessary biopsies. Previous work has suggested that urinary volatile organic compound (VOC) biomarkers may be able to distinguish PrCa cases from benign disease. The behavior of the nematode Caenorhabditis elegans has been proposed as a tool to take advantage of these potential VOC profiles. To test the ability of C. elegans Bristol N2 to distinguish PrCa cases from controls, we performed chemotaxis assays using human urine samples collected from men screened for PrCa. Behavioral response of nematodes towards diluted urine from PrCa cases was compared to response to samples from cancer-free controls. Overall, we observed a significant attraction of young adult-stage C. elegans nematodes to 1:100 diluted urine from confirmed PrCa cases and repulsion of C. elegans to urine from controls. When C. elegans chemotaxis index was considered alongside prostate-specific antigen levels for distinguishing cancer from cancer-free controls, the accuracy of patient classification was 81%. We also observed behavioral attraction of C. elegans to two previously reported VOCs to be increased in PrCa patient urine. We conclude nematode behavior distinguishes PrCa case urine from controls in a dilution-dependent manner.


2019 ◽  
Vol 46 (4) ◽  
pp. 249-252 ◽  
Author(s):  
Jeff Nisker

This narrative ethics exploration stems from my happy prostate-specific antigen (PSA) story, though it should not have been, as I annually refuse my family physician’s recommendation to purchase PSA screening. The reason for my refusal is I teach ethics to medical students and of course must walk the talk, and PSA screening is not publicly funded in the province of Ontario, Canada. In addition, I might have taken false comfort in ‘but all you need is a good index finger’ to detect prostate cancer, expounded by a senior physician at a national medical conference in 2010, and applauded by the large audience of physicians. I was compelled to begin this exploration out of survivor guilt, although I will not be a survivor for long, and as a mea culpa to the men similarly situated to me in having late diagnosis of prostate cancer, aggressive tumours and multiple metastases, but who unlike me are dead because they did not experience the physician–educator-based exceptionisms and coincidences that permit me to still be alive. Although my PSA story will always be a happy story, even when my life ends in a few years, the initiation of public funding of PSA screening for all men over 50 would make my PSA story an even happier story.


2019 ◽  
Author(s):  
Amanda Kvarven ◽  
Eirik Strømland ◽  
Magnus Johannesson

Andrews & Kasy (2019) propose an approach for adjusting effect sizes in meta-analysis for publication bias. We use the Andrews-Kasy estimator to adjust the result of 15 meta-analyses and compare the adjusted results to 15 large-scale multiple labs replication studies estimating the same effects. The pre-registered replications provide precisely estimated effect sizes, which do not suffer from publication bias. The Andrews-Kasy approach leads to a moderate reduction of the inflated effect sizes in the meta-analyses. However, the approach still overestimates effect sizes by a factor of about two or more and has an estimated false positive rate of between 57% and 100%.


Cancers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 359
Author(s):  
Takahiro Kimura ◽  
Shun Sato ◽  
Hiroyuki Takahashi ◽  
Shin Egawa

The incidence of prostate cancer (PC) has been increasing in Asian countries, where it was previously low. Although the adoption of a Westernized lifestyle is a possible explanation, the incidence is statistically biased due to the increase in prostate-specific antigen (PSA) screening and the accuracy of national cancer registration systems. Studies on latent PC provide less biased information. This review included studies evaluating latent PC in several countries after excluding studies using random or single-section evaluations and those that did not mention section thickness. The findings showed that latent PC prevalence has been stable since 1950 in Western countries, but has increased over time in Asian countries. Latent PC in Asian men has increased in both prevalence and number of high-grade cases. Racial differences between Caucasian and Asian men may explain the tumor location of latent PC. In conclusion, the recent increase in latent PC in Asian men is consistent with an increase in clinical PC. Evidence suggests that this increase is caused not only by the increase in PSA screening, but also by the adoption of a more Westernized lifestyle. Autopsy findings suggest the need to reconsider the definition of clinically insignificant PC.


2005 ◽  
Vol 117 (13-14) ◽  
pp. 457-461 ◽  
Author(s):  
Christian Vutuc ◽  
Eva S. Schernhammer ◽  
Gerald Haidinger ◽  
Thomas Waldhör

2006 ◽  
Vol 24 (6) ◽  
pp. 878-883 ◽  
Author(s):  
Mark Redston ◽  
Carolyn C. Compton ◽  
Brent W. Miedema ◽  
Donna Niedzwiecki ◽  
Jeannette M. Dowell ◽  
...  

Purpose To determine whether sentinel lymph node (LN) sampling (SLNS) could reduce the number of nodes required to characterize micrometastatic disease (MMD) in patients with potentially curable colon cancer. Patients and Methods Cancer and Leukemia Group B 80001 was a study to determine whether SLNS could identify a subset of LNs that predicted the status of the nodal basin for resectable colon cancer and, therefore, could be extensively evaluated for the presence of micrometastases. Patients enrolled onto this study underwent SLNS after injection of 1% isosulfan blue, and both sentinel nodes (SNs) and non-SNs obtained during primary tumor resection were sectioned at multiple levels and stained using anti–carcinoembryonic antigen and anticytokeratin antibodies. Results Using standard histopathology, SNs failed to predict the presence of nodal disease in 13 (54%) of 24 node-positive patients. Immunostains were performed for patients whose LNs were negative by standard histopathology. Depending on the immunohistochemical criteria used to assign LN positivity, SN examination resulted in either an unacceptably high false-positive rate (20%) or a low sensitivity for detection of MMD (40%). Conclusion By examining both SNs and non-SNs, this multi-institutional study showed that SNs did not accurately predict the presence of either conventionally defined nodal metastases or MMD. As a result, SLNS is not a useful technique for the study of MMD in patients with colon cancer.


2017 ◽  
Vol 63 (8) ◽  
pp. 722-725 ◽  
Author(s):  
Marcus V. Sadi

Summary Screening of prostate cancer with prostate-specific antigen (PSA) is a highly controversial issue. One part of the controversy is due to the confusion between population screening and early diagnosis, another derives from problems related to the quality of existing screening studies, the results of radical curative treatment for low grade tumors and the complications resulting from treatments that affect the patient’s quality of life. Our review aimed to critically analyze the current recommendations for PSA testing, based on new data provided by the re-evaluation of the ongoing studies and the updated USPSTF recommendation statement, and to propose a more rational and selective use of PSA compared with baseline values obtained at an approximate age of 40 to 50 years.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 5155-5155
Author(s):  
J. H. Hayes ◽  
M. J. Barry ◽  
P. W. Kantoff ◽  
J. E. Stahl

5155 Background: PSA-based screening has been widely adopted in the US although a mortality benefit has yet to be demonstrated. The disutility of screening and quality of life of men diagnosed and treated after screening are critical issues in assessing its benefit and harm. The purpose of this model is to estimate the effect of one-time screening for prostate cancer using Prostate Specific Antigen (PSA) and DRE (digital rectal exam) on life expectancy (LE) and Quality Adjusted Life Expectancy (QALE) in the context of current diagnostic and treatment practice. Methods: A semi-Markov state transition simulation describes the relevant health states. Two strategies were compared: 1) Screening - single screening PSA and DRE; 2) No Screening - patients diagnosed after developing symptoms. Markov cycle length was 1 year. Transition probabilities and utility weights were developed from review of the literature and expert opinion. Sensitivity analyses were performed on all parameters. A PSA threshold of 4 ng/mL and age 65 were used for the base case. The model was created using TreeAge software. Results: For our base case, a single screening conferred a LE benefit of 0.37 y (15.86 vs 15.49 y) and a QALE benefit of 0.20 QALYs (15.62 vs 15.42 QALYs). Predicted 10 y cancer specific survival for screen-diagnosed men was 95.7% vs SEER 97.7%. The model predicted 9.5% of screened patients would have metastatic disease at diagnosis vs 5% in SEER (4% unknown stage); in unscreened men, this rate was 18/100,000 vs 15/100,000 in SEER. Sensitivity Analyses of Utilities (SA): The single screen model was relatively insensitive to SA of utilities: a 20% single cycle toll on one-time PSA screening disutility was required to eliminate the benefit of screening. The disutility of positive PSA with negative biopsy slightly affected QALE: a toll of 0.25 QALYs decreased QALE from 15.62 to 15.61 QALYs. Conclusions: Our model reveals a modest benefit to one-time screening for prostate cancer. This one-time screening model is relatively insensitive to utility SA; however, the importance of incorporating psychological effects of PSA screening in recurrent screening is to be determined. The impact of serial screening, lead time, PSA threshold, and cost effectiveness on LE and QALE is being analyzed. No significant financial relationships to disclose.


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