Tumor Buds Show Reduced Expression of Laminin-5 Gamma 2 Chain in DNA Mismatch Repair Deficient Colorectal Cancer
Bibliographic record
Abstract
PURPOSE: Tumor budding at the invasive margin of colorectal cancer is an important adverse prognostic factor. The subset of colorectal cancer that is deficient in DNA mismatch repair has been associated with a good prognosis. It is hypothesized that tumor budding in this subset may lack biologic aggressiveness because it is not associated with aberrant expression of the independent prognostic factor, laminin-5 gamma 2. METHODS: Eighty colorectal cancers with high-grade tumor budding were studied, including nine sporadic colorectal cancers with immunohistochemical loss of expression of MLH1 (MLH1(-)), seven colorectal cancers from patients with hereditary nonpolyposis colorectal cancer, and 64 sporadic colorectal cancers expressing both MLH1 and MSH2 (MLH1(+)). Two regulatory mechanisms for laminin-5 gamma 2 expression were explored, including aberrant nuclear expression of beta-catenin by immunohistochemistry and promoter methylation of laminin-5 gamma 2 by methylation-specific polymerase chain reaction. RESULTS: Only three of nine MLH1(-) colorectal cancers showed expression of laminin-5 gamma 2 compared with 46 of 64 MLH1(+) colorectal cancers (P = 0.05). Only two of seven hereditary nonpolyposis colorectal cancers expressed laminin-5 gamma 2 compared with MLH1(+) colorectal cancers (P= 0.03). Expression of nuclear beta-catenin was more frequent (58 percent) in MLH1(+) colorectal cancers compared with MLH1(-) colorectal cancers (11 percent, P = 0.01). Methylation of laminin-5 gamma 2 was found in 5 of 38 (13 percent) cases but did not differ among colorectal cancer subsets. Four of five colorectal cancers with methylation of laminin-5 gamma 2 were scored as negative for laminin-5 gamma 2 by immunohistochemistry. CONCLUSIONS: The reduced expression of laminin-5 gamma 2 in colorectal cancers with deficient DNA mismatch repair may underlie a variant of tumor budding that is relatively nonaggressive.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.001 |
| 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) | 0.000 | 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 teacher head, 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".