scholarly journals Large discrepancy between prostate-specific antigen results from different assays during longitudinal follow-up of a prostate cancer patient

1996 ◽  
Vol 42 (4) ◽  
pp. 637-641 ◽  
Author(s):  
H L Van Duijnhoven ◽  
N C Péquériaux ◽  
J P Van Zon ◽  
M A Blankenstein

Abstract A case is presented of a patient with stage D prostatic carcinoma, from whom a serum sample proved to be an outlier in a correlation study performed with a 2nd-generation prostate-specific antigen (PSA) assay on the Immulite system (6.4 micrograms/L) and IMx (101 micrograms/L). Clearly, the PSA result reported by Immulite was falsely low. For nine longitudinal samples, Immulite results were approximately 20-fold lower than the IMx value (range of IMx results 5-275 micrograms/L). A selection of the samples was analyzed with the ACS:180, ES-600, and IMx (all > 180 micrograms/L); Immulite, DPC Coat-A-Count IRMA, Immuno 1, AIA-pack, and Tandem-R (all <70 micrograms/L); and Immulite free PSA assay (41 micrograms/L). Gel filtration demonstrated that apart from the alpha1-antichymotrypsin (ACT) complex, no other complexes were found. However, the sample consisted of 53% free PSA (IMx). Possibly, a change of conformation of the PSA molecule resulted in a decreased binding to ACT and a reduced affinity of the antibodies used in the affected assays.

1995 ◽  
Vol 41 (9) ◽  
pp. 1273-1282 ◽  
Author(s):  
Z Chen ◽  
A Prestigiacomo ◽  
T A Stamey

Abstract We describe for the first time a protocol to purify to apparent homogeneity an in vitro-prepared complex of prostate-specific antigen (PSA) and alpha 1-antichymotrypsin (ACT) by using a combination of gel filtration and ion-exchange chromatography. The purity of the PSA-ACT complex was confirmed by gel electrophoresis and Western blot. The PSA-ACT complex was stable in the pH range 6.0 to 7.8; it was also stable in various matrices, temperatures, and high concentrations of salt. Purification of the PSA-ACT complex was highly reproducible. An absorptivity of 0.99 L x g-1 x cm-1 at 280 nm was assigned to the PSA-ACT complex, based on amino acid analysis. Because PSA and ACT bind in a 1:1 molar ratio, we determined the molecular mass of the PSA-ACT complex as the mass encoded by the cDNA of ACT (plus 26% carbohydrate) plus the molecular mass of PSA (28,430 Da), which totals 89,280 Da. Using this material, we made two common calibrators, one of 100% PSA-ACT complex and one of 90% PSA-ACT complex plus 10% free PSA by volume (90:10 calibrator). Substitution of these calibrators for the manufacturers' calibrators in nine commercial immunoassays substantially reduced differences between immunoassays, especially for serum PSA values between 4 and 10 micrograms/L. The 90:10 calibrator is recommended as a universal calibrator for international standardization of PSA immunoassays.


2021 ◽  
pp. 284-289
Author(s):  
Hiroyuki Yoshitake ◽  
Shoji Oura ◽  
Tomoyuki Yamaguchi ◽  
Shinichiro Makimoto

An 83-year-old man with core needle biopsy-proven Gleason score 5 prostate cancer had received radiotherapy including 18 Gy brachytherapy to the prostate cancer, leading to no locoregional and distant recurrence for more than 5 years with the normalization of elevated prostate-specific antigen (PSA) level before the radiotherapy. Due to the enlargement of coexisting ground glass nodule (GGN) in the left lung from 1 to 2.1 cm, the patient underwent wide resection of the GGN 7 years later. Under the diagnosis of adenocarcinoma in situ of the lung, follow-up computed tomography 6 months after the wide resection showed a rapid enlargement of a solid nodule having been judged as a presumed inflammatory nodule in the middle lobe, highly suggesting a malignant neoplasm of the lung. Due to both the tall columnar atypical cells with trabecular pattern on frozen section and no elevation of serum PSA level, we judged the nodule as a primary adenocarcinoma of the lung and further resected the middle lobe with lymph node dissection. Immunostaining of the tumor showed all the CK7, CK20, TTF-1, napsin A, synaptophysin, chromogranin, CD56, CDX2, p53, beta-catenin, and MUC2 negative, and PSA highly positive, clearly showing the solid nodule as a solitary lung metastasis of the prostate cancer. Physicians should note the possible solitary lung metastasis of prostate cancer, especially bearing indolent biology, with no elevation of the PSA level even after the completion of standard 5-year follow-up.


2003 ◽  
Vol 127 (3) ◽  
pp. 345-348 ◽  
Author(s):  
Alexander Kratz ◽  
Kent B. Lewandrowski ◽  
Arthur J. Siegel ◽  
Patrick M. Sluss ◽  
Kelly Y. Chun ◽  
...  

Abstract Context.—Prostate-specific antigen (PSA) is an important tumor marker for the most frequently diagnosed cancer in the United States. A major limitation of this marker is falsely elevated results in patients who are found not to have prostate cancer. The effects of vigorous physical exertion on PSA concentrations are controversial. Objective.—To determine the effects of marathon running on PSA levels. Design.—Measurement of total and free PSA levels in the sera of participants in a marathon before and within 4 and 24 hours after the race. Results.—None of the participants had elevated total PSA levels before the race. Although we found no statistically significant changes in average total or free PSA concentrations at either time point, after the marathon, 2 (11%) of 18 runners had total PSA concentrations outside the standard reference range. Changes in total PSA levels did not correlate with age or prerace PSA concentrations. Free PSA levels were not statistically significantly changed after the race and did not allow a reliable determination of exercise-induced PSA elevations. Conclusions.—Although it may not be necessary for men to abstain from exercise involving running before blood draws for PSA analysis, elevated PSA concentrations may be observed in some individuals after participation in a major sporting event. In these cases, repeat measurements should be considered at a time significantly removed from such exercise.


2013 ◽  
Vol 3 (3) ◽  
pp. 213 ◽  
Author(s):  
Stéphane Bolduc ◽  
Brant A. Inman ◽  
Louis Lacombe ◽  
Yves Fradet ◽  
Roland R. Tremblay

Purpose: We assessed the role of urinary prostate-specific antigen(uPSA) in the follow-up of prostate cancer after retropubic radicalprostatectomy (RRP) for the early detection of local recurrences.Methods: We recruited 50 patients previously treated for prostatecancer with RRP and who had not experienced a prostatespecificantigen (PSA) recurrence within their first postoperativeyear into a cross-sectional laboratory assessment and prospective6-year longitudinal follow-up study. We defined biochemicalfailure as a serum PSA (sPSA) of 0.3 μg/L or greater. Patientsprovided blood samples and a 50-mL sample of first-voided urine.We performed Wilcoxon rank-sum and Fisher exact tests for statisticalanalysis.Results: The median sPSA was 0.13 μg/L. The median uPSA was0.8 μg/L, and was not significantly different when comparingGleason scores or pathological stages. Of the 50 patients, 27 initiallyhad a nondetectable sPSA but a detectable uPSA, and11 patients experienced sPSA failure after 6 years. Six patients haddetectable sPSA and uPSA initially. Fifteen patients were negativefor both sPSA and uPSA, and 13 remained sPSA-free after 6 years.The odds ratio (OR) of having sPSA failure given a positive uPSAtest was 4.5 if sPSA was undetectable, but was reduced to 2.6 ifsPSA was detectable. The pooled Mantel–Haenszel OR of 4.2 suggestedthat a detectable uPSA quadrupled the risk of recurrence,independent of whether sPSA was elevated or not. The sensitivityof uPSA for detecting future sPSA recurrences was 81% andspecificity was 45%.Conclusion: Urinary PSA could contribute to an early detection oflocal recurrences of prostate cancer after a radical prostatectomy.Objectif : Nous avons évalué le rôle de l’antigène prostatiquespécifique (APS) urinaire dans le suivi du cancer de la prostateaprès prostatectomie radicale rétropubienne (PRR) pour le dépistageprécoce de récidives locales.Méthodes : Cinquante patients atteints de cancer de la prostatetraités par PRR et n’ayant présenté aucune récidive avec anomaliede l’APS dans l’année suivant l’intervention chirurgicale ontété inscrits à une étude transversale par épreuves de laboratoireavec suivi longitudinal prospectif sur 6 ans. L’échec sur le planbiochimique était défini comme un taux d’APS sérique de 0,3 μg/Lou plus. Les patients devaient fournir des échantillons de sanget un échantillon d’urine du matin de 50 mL. Les analyses statistiquesreposaient sur le test de Wilcoxon et la méthode exactede Fisher.Résultats : La valeur médiane de l’APS sérique était de 0,13 μg/L.La valeur médiane de l’APS urinaire était de 0,8 μg/L; la différenceétait non significative quand on tenait compte des scores deGleason ou des stades pathologiques. Sur les 50 patients,27 présentaient des taux d’APS sérique non décelables au début,mais des taux d’APS urinaire décelables; 11 patients ont présentéun échec quant aux taux d’APS sérique après 6 ans. Six patientsavaient des taux d’APS sérique et urinaire décelables au départ.Quinze patients n’avaient aucun taux décelable d’APS sérique ouurinaire, et aucun APS sérique n’était toujours décelable chez13 patients après 6 ans. Le rapport de risque d’un échec quantaux taux d’APS sérique après détection d’APS urinaire est de 4,5en l’absence d’un taux d’APS sérique décelable, mais diminueà 2,6 en présence d’un taux d’APS sérique décelable. Le rapportde risque cumulé de 4,21 calculé par la méthode deMantel–Haenszel porte à croire que des taux d’APS urinaire décelablesquadruplent le risque de présenter une récidive, queles taux sériques soient élevés ou non. La sensibilité du test dedépistage de l’APS urinaire pour la détection des récidives avecanomalie des taux sériques était de 81 %, et la spécificité, de 45 %.Conclusion : Le taux d’APS urinaire peut contribuer à un dépistageprécoce des récidives locales après une prostatectomie radicale.


2014 ◽  
Vol 8 (9-10) ◽  
pp. 702 ◽  
Author(s):  
Paul Toren ◽  
Lih-Ming Wong ◽  
Narhari Timilshina ◽  
Shabbir Alibhai ◽  
John Trachtenberg ◽  
...  

Introduction: The use of prostate-specific antigen (PSA) in active surveillance (AS) for prostate cancer is controversial. Some consider it an unreliable marker and others as sufficient evidence to exclude patients from AS. We analyzed our cohort of AS patients with a PSA over 10 ng/mL.Methods: We included patients who had clinical T1c–T2a Gleason ≤6 disease, and ≤3 positive cores with ≤50% core involvement at diagnostic biopsy and ≥2 total biopsies. Patients were divided into 3 groups: (1) those with baseline PSA >10 ng/mL, (2) those with a PSA rise >10 ng/mL during follow-up; and (3) those with a PSA <10 ng/mL throughout AS. Adverse histology was defined as biopsy parameters exceeding the entry criteria limits. We further compared this cohort to a concurrent institutional cohort with equal biopsy parameters treated with immediate radical prostatectomy.Results: Our cohort included 698 patients with a median follow-up of 46.2 months. In total, 82 patients had a baseline PSA >10 ng/mL and 157 had a PSA rise >10 ng/mL during surveillance. No difference in adverse histology incidence was detected between groups (p = 0.3). Patients with a PSA greater than 10 were older and had higher prostate volumes. Hazard ratios for groups with a PSA >10 were protective against adverse histology. Larger prostate volume and minimal core involvement appear as factors related to this successful selection of patients to be treated with AS.Conclusion: These results suggest that a strict cut-off PSA value for all AS patients is unwarranted and may result in overtreatment. Though lacking long-term data and validation, AS appears safe in select patients with a PSA >10 ng/mL and low volume Gleason 6 disease.


2015 ◽  
Vol 33 (1) ◽  
pp. 16.e1-16.e7 ◽  
Author(s):  
Heikki Seikkula ◽  
Kari T. Syvänen ◽  
Samu Kurki ◽  
Tuomas Mirtti ◽  
Pekka Taimen ◽  
...  

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