Correlation of lactate dehydrogenase (LDH) isoenzyme profile with outcome in advanced colorectal cancer (CRC) patients (pts) treated with chemotherapy and bevacizumab (BEV) or cediranib (CED).
Bibliographic record
Abstract
e13541 Background: There is a clinical need for predictive biomarkers of efficacy of VEGF signaling inhibitors (VSIs). LDH is a tetramer that can include any combination of the M and H subunits. LDH4 and 5 isoenzymes are composed mostly of the M subunit and are more abundant in hypoxic conditions. We speculated that the levels of LDH isoenzymes in pts serum may correlate with outcome of pts treated with VSIs. HORIZON I trial enrolled pts that were randomized to mFOLFOX6 with BEV or CED. A retrospective exploratory analysis was performed on baseline serum samples of these pts. Methods: Total serum LDH was tested on fresh samples during the conduct of the trial. About 2 years after the trial, frozen samples stored at -70 degrees were tested for total serum LDH and LDH isoenzymes, measured by agarose electrophoresis and a colorimetric enzymatic assay. Relative levels of M and H subunits were derived based on the known structure of each isoenzyme. Progression free survival (PFS) and overall survival (OS) were compared by subgroups of total LDH and LDH isoenzyme levels. P values were not calculated for these exploratory analyses. Results: Baseline total LDH levels from fresh serum were available for 207 pts. Total and isoenzyme LDH levels were available for frozen serum samples of 189 pts. Total LDH in the frozen and fresh samples correlated (R=0.9). Distant isoenzymes (e.g. LDH1 and 5) were negatively correlated. High M/H subunits ratio correlated with poor OS (HR=1.804, 95%CI 1.24-2.620). A non-significant trend for better OS to CED-treated vs. BEV-treated pts was seen in pts with high M/H ratio (e.g., CED 30mg vs BEV HR=0.685, 95%CI 0.382-1.23). Conclusions: Evaluation of LDH isoenzymes is feasible using serum samples kept frozen for 2 years. A negative correlation is seen between hypoxic-related and oxic-related isoenzymes. In CRC pts treated with a VSI, LDH isoenzyme hypoxia-associated profile correlates with poorer outcome. LDH isoenzyme profile as a possible predictive biomarker for benefit from CED vs. BEV requires further investigation.
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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 | 0.000 | 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".