Analytical validation of serum proteomic profiling for diagnosis of prostate cancer: sources of sample bias.

Author(s): McLerran D, Grizzle WE, Feng Z, Bigbee WL, Banez LL, Cazares LH, Chan DW, Diaz J, Izbicka E, Kagan J, Malehorn DE, Malik G, Oelschlager D, Partin A, Randolph T, Rosenzweig N, Srivastava S, Thompson IM, Thornquist M, Troyer D, Yasui Y, Zhang Z, Zhu L, Semmes OJ

Publication: Clin Chem, 2008, Vol. 54, Page 44-52

PubMed ID: 17981926 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of the study was to assess the diagnostic applicability of a newly designed algorithm for the analysis of proteomic data to reliably distinguish sera of prostate cancer patients from those of healthy controls. The algorithm used in this study was based on the analysis of serum samples from 181 patients with prostate cancer, 143 patients with benign prostatic hyperplasia and 220 normal control and was validated with serum from a separate cohort of 42 prostate cancer patients and 42 controls without prostate cancer. All specimens were aliquoted and aliquots of each specimen were sent to six different SELDI-TOF mass spectrometry for analysis. Specimens in the validation cohort were used for a blinded analysis and then assigned to a group based on the decision algorithm.

   Summary of Findings:

   Evaluation of the algorithm's diagnostic performance was compromised by preanalytical sample bias. Sera collected from prostate patients before 1996 exhibited different mass spectrometry profiles than those collected during or after 1996. Further, sera samples collected from prostate cancer patients during or after 1996 exhibited spectral profiles more similar to normal controls collected during the same time period than samples collected from prostate cancer patients prior to 1996. Potential confounding parameters identified by the authors included storage duration and the number of freeze thaw cycles.

   Biospecimens

   • Bodily Fluid - Serum

   Preservative Types

   • Frozen

   Diagnoses:

   • Neoplastic - Carcinoma
   • Neoplastic - Benign
   • Normal

   Platform:

   Analyte	Technology Platform
   Protein	SELDI-TOF MS

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Storage duration	7-28 yr
   Storage	Freeze/thaw cycling	1 cycle 2 cycles >2 cycles

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