Topoisomerase IIα Expression in Pituitary Adenomas and Carcinomas: Relationship to Tumor Behavior
Bibliographic record
Abstract
DNA topoisomerase IIalpha (Topo IIalpha) is a molecular and immunohistochemical marker that indicates proliferation rate and is the target for several antineoplastic agents. The present immunohistochemical study of a large series of surgically removed pituitary tumors was designed to assess the prognostic significance of Topo IIalpha expression relative to patient age, gender, tumor type and size, invasiveness, metastasis, MIB-1-labeling index and angiogenesis. Changes of Topo IIalpha expression in the tumors treated with bromocriptine and octreotide, a long-acting somatostatin analogue were also investigated. Topo IIalpha immunopositivity was detected only in the nuclei of tumor cells. Gonadotroph adenomas, null cell adenomas, and ACTH-producing adenomas had the lowest Topo IIalpha indices, whereas primary pituitary carcinomas and silent type 3 adenomas presented the highest counts. The statistical study demonstrated no significant correlation between Topo IIalpha expression, patient gender, and vascularity. In contrast, significant negative correlation was found between Topo IIalpha expression and patient age. Topo IIalpha expression was significantly higher in invasive than noninvasive tumors. A tendency to have higher counts was also observed in microadenomas compared with in macroadenomas. Although Topo IIalpha and MIB-1 indices were similar in most tumor types, no significant correlation between Topo IIalpha and MIB-1-labeling indices (r =.16, P =.09) was found. Only non-functioning adenomas showed positive correlation (r =.41, P =.006) between both proliferation markers. Our results demonstrated a significant decrease in Topo IIalpha index in octreotide-treated, GH-producing adenomas, compared with untreated tumors, but no significant changes were observed in bromocriptine-treated, PRL-producing adenomas. The present study showed no significant advantage of Topo IIalpha over MIB-1 as a prognostic marker; however, Topo IIalpha may provide crucial information regarding selection of adenohypophyseal tumors responsive to antineoplastic therapy, such as invasive pituitary adenomas and pituitary carcinomas, which exhibit a high Topo IIalpha index.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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".