Do clinical trials of neoadjuvant chemotherapy for locally advanced breast cancer (LABC) overestimate the actual response rates observed in clinical practice?
Bibliographic record
Abstract
890 Background: Neoadjvuant chemotherapy (NAC) is an established standard of care for LABC. Evidence shows that both clinical (cCR) and pathologic (pCR) complete response predicts for locoregional recurrence, disease free and overall survival. However, the definition of pCR is not universal and there exists variation as to the inclusion of residual intraductal and microinvasive disease. Phase II and III trials with different NAC regimens report cCR rates of 60–80% with corresponding pCR rates of 10–39%. Purpose: To compare response rates of cCR and pCR in a prospectively collected patient cohort to those reported in the literature for women with LABC. Methods: Patients with clinical stage III and primary tumors greater than 5cm were defined as having LABC. 49 pts were treated between Sept 2003 & Nov 2004 and were eligible for the study. Two pts were excluded as one discontinued therapy secondary to mitral valve disease and the second moved out of the country to pursue alternative therapies. Results: Median pt age was 50 (range 27 to 76). Clinical staging at diagnosis showed 12% IIB, 48% IIIA, 34% IIIB and 6% IIIC. Eighty-eight percent were clinical stage III at presentation and of these, seven (15%) had T4d inflammatory breast cancers. Eighty three percent had clinical axillary node involvement, 51% of tumours were hormone receptor positive & 38% overexpressed her2neu. Thirty four pts (72%) received an anthracycline based regimen & thirteen pts (28%) received both a taxane and anthracycline based regimen. Following neoadjuvant chemotherapy, 32% of pts had a cCR and 26% had a cPR, for a total clinical response rate of 58%. pCR was seen in 4 (9%) pts. Conclusions: The cCR and pCR response rates in this study were 28% and 9% respectively. This is clearly lower than reported in clinical trials and may reflect the advanced nature of patients selected for neoadjuvant therapy in actual practice. Depending on the definition of pCR used in this study, the range of pCR varied from 4.2% to 10.6% (using definitions form Chevallier et al and NSABP-27 respectively). Thus, it is essential that the pathologic response definition used in each trial be considered when interpreting study outcomes. No significant financial relationships to disclose.
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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 | 0.277 | 0.416 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.003 | 0.002 |
| Bibliometrics | 0.001 | 0.003 |
| Science and technology studies | 0.001 | 0.003 |
| Scholarly communication | 0.003 | 0.003 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.003 | 0.002 |
| Insufficient payload (model declined to judge) | 0.003 | 0.002 |
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; the direct Gemma label and the distilled Codex classifier agree on what is shown here.
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".