Molecular profiling of patients (pts) with advanced colorectal cancer (CRC): Princess Margaret Cancer Centre experience.
Bibliographic record
Abstract
459 Background: The prevalence of somatic mutations other than KRAS, PIK3CA and BRAF in CRC has not been well described. This study reports molecular profiling of pts with advanced CRC in clinical practice. Methods: Pts with advanced CRC are enrolled in an ongoing institution-wide screening program. Molecular profiling is performed on FFPE archival tissues using a customized Sequenom panel (23 genes, 279 mutations) or the Illumina MiSeq TruSeq Amplicon Cancer Panel (48 genes, 212 amplicons, ≥ 500x coverage) in our CLIA-certified laboratory. PTEN negative tumor is defined by IHC with H score <1. Demographic and clinical data are collected. Data was analyzed by chi-square test. Results: From March 2012 to August 2013, 132 pts were enrolled. One or more mutations were found in 50% (58/117) and 93%(14/15) of pts using Sequenom and MiSeq platforms respectively. Mutation rate was 40% for KRAS, 9% for PIK3CA, 2% for BRAF, 4% for NRAS, and 1% for each of CTNNB1, ERBB2, FGFR3, and EGFR. Mutations outside of codons 12/13 were found in 8% (4/53) of tumors with KRAS mutations. MiSeq showed additional mutations including ERBB4 (1/15), SMAD4 (1/15), FRXW7 (1/5), APC (5/15), and TP53 (12/15) in CRC. Co-mutation with KRAS was found in 58% (7/12) of pts with PIK3CA mutation and 80% (4/5) of pts with APC mutation. PTEN negative tumor was present in 20% (11/55) of pts. Presence of any mutation was significantly more common for pts with right-sided CRC (73%) compared to those with left-sided CRC (47%) and rectal CRC (38%) (p < 0.01). There was a trend toward increased proportion of KRAS mutation in right-sided CRC (p=0.06). There was no difference in age, ethnicity, gender, smoking status, stage at presentation, pathology grade, and response to first-line chemotherapy between right and left-sided CRC. Conclusions: Somatic alterations are common in advanced CRC. Targeted next-generation DNA sequencing identifies additional clinically relevant alterations than multiplex genotyping. Differences in the mutation profile of right and left-sided CRC tumors should be further investigated. Updated results will be presented at the meeting.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".