Reproducibility of p53 immunohistochemistry in bladder tumors. National Cancer Institute, Bladder Tumor Marker Network.
Bibliographic record
Abstract
The National Cancer Institute Bladder Tumor Marker Network conducted a study to evaluate the reproducibility of immunohistochemistry for measuring p53 expression in bladder tumors. Fifty paraffin blocks (10 from each of the five network institutions) were chosen at random from among high-grade invasive primary bladder tumors. Two sections from each block were sent to each laboratory for staining and scoring, and then all sections were randomly redistributed among the laboratories for a second scoring. Intra- and interlaboratory reproducibility was assessed with regard to both staining and scoring. For overall assessments of p53 positivity, the results demonstrated that intralaboratory reproducibility was quite good. Concordance across the five participating laboratories was high for specimens exhibiting no or minimal nuclear immunostaining of tumor cells or high percentages of tumor cells with nuclear immunoreactivities. However, there was a reduced level of concordance on specimens with percentages of stained tumor cells in an intermediate range. The discordancies were due mainly to staining differences in one of the five laboratories and scoring differences in another laboratory. These results indicate that some caution must be used in comparing results across studies from different groups. Standardization of staining protocols and selection of a uniform threshold for binary interpretation of results may improve assay reproducibility between laboratories.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.102 | 0.086 |
| Meta-epidemiology (narrow) | 0.000 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".