Does Neoadjuvant Therapy Alter KRAS and/or MSI Results in Rectal Adenocarcinoma Testing?
Bibliographic record
Abstract
To our knowledge, the genotoxic effects of neoadjuvant chemoradiation therapy on molecular diagnostic testing results are unknown. However, if neoadjuvant treatments were to alter molecular test results, clinical decision-making could be misled. This raises questions about the appropriateness of using posttreatment tumor for testing. To address this, rectal adenocarcinomas both before and after neoadjuvant treatment were evaluated for alterations in KRAS and microsatellite instability (MSI) testing. Neoadjuvant chemoradiation therapy is common in this tumor type, and alterations in these 2 tests would significantly impact management. A total of 17 rectal adenocarcinoma patients with available pretreatment and posttreatment tumor were studied. MSI testing used the revised National Cancer Institute panel of 5 mononucleotide microsatellite repeats, comparing cancers with matched normal control tissues. KRAS codon 12-point and 13-point mutations were examined by polymerase chain reaction amplification and bidirectional sequencing. MSI and KRAS results were unchanged comparing rectal cancer tissue before and after chemoradiotherapy in all 17 patients (P=1.000; 95% CI: 0.3969-2.520). All 17 tumors (100%) were microsatellite stable. KRAS testing identified 12 (72%) wild-type tumors and 5 (28%) codon 12 or 13 mutant tumors with identical KRAS point mutations before and after treatment. The identified MSI and KRAS mutational prevalences parallel those reported in the rectal cancer literature. Neoadjuvant therapy did not alter KRAS codon 12 or 13 or MSI results in rectal adenocarcinoma, providing evidence that either pretreatment biopsy or posttreatment resection tissues are appropriate for testing.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.007 | 0.035 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| 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".