Analysis of metabolic response (MR) by positron emission tomography (PET) compared with tumor response by computed tomography (CT) from MPACT, a phase III trial comparing <i>nab</i>-paclitaxel (<i>nab</i>-P) plus gemcitabine (G) versus G alone for patients (pts) with metastatic adenocarcinoma of the pancreas.
Bibliographic record
Abstract
254^ Background: In the MPACT trial, nab-P + G demonstrated superior efficacy vs G alone for the treatment of metastatic pancreatic cancer (PC). Pts with an MR (according to EORTC criteria) had a 5-month improvement in median overall survival (OS) vs those without an MR (13 vs 8 months for nab-P + G and 12 vs 7 months for G alone). This analysis examines the relationship between MR by PET and tumor response by CT. Methods: Previously untreated pts (N = 861) with metastatic PC were randomized 1:1 to receive nab-P 125 mg/m 2 + G 1000 mg/m 2 on days 1, 8, and 15 every 4 wk or G alone 1000 mg/m 2 weekly for 7 wk followed by 1 wk of rest (cycle 1) and then days 1, 8, and 15 every 4 wk (cycle ≥ 2). Tumor responses were evaluated every 8 wk by CT using RECIST v1.0. CT-documented disease progression led to treatment discontinuation. PET scans were evaluated at baseline, wk 8, and wk 16. Results: In 257 pts with a PET scan at baseline, 252 (98%) had ≥ 2 PET-avid lesions. The rate of MR (complete [CMR] or partial [PMR]) was higher for nab-P + G vs G alone (63% vs 38%; P < 0.0001). The ORRs by CT (complete response + partial response [CR/PR]) in the same pts were 31% for nab-P + G vs 11% for G. In a pooled-treatment-arm analysis (n = 255), 130 pts (51%) had an MR by PET, and 54 (21%) had a CR or PR by CT. Among pts with an MR by PET, 32% had a CR or PR, 43% had stable disease, and 16% had progressive disease (PD) by CT. Pts who had an MR by PET in the absence of a CR or PR by CT (n = 88) had a median OS of 10 months (table). Conclusions: Rates of MR by PET in this trial were > 2-fold the response rates by CT, suggesting that PET may be a more sensitive marker of tumor response. Of the pts without a CR or PR by CT, those with an MR by PET had a longer median OS vs those without one. A set of pts who had PD by CT exhibited an MR by PET. Thus, PET may identify a set of pts who may benefit from continued treatment despite PD by CT. Further research is needed to explore the radiological and clinical characteristics of these pts. Clinical trial information: NCT00844649. [Table: see text]
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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 | 0.008 | 0.007 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.005 | 0.002 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".