Impact of reduced dose intensity of adjuvant anthracycline based chemotherapy in a population based cohort of stage I-II breast cancers
Bibliographic record
Abstract
552 Background: Reductions in the dose intensity (DI) of adjuvant doxorubicin and cyclophosphamide (AC) chemotherapy in the treatment of early stage breast cancer are frequently required, with the impact on clinical outcome uncertain. We examined whether a reduced DI had an impact on relapse free survival (RFS), breast cancer specific survival (BCSS) or overall survival (OS) in a population-based cohort of early stage breast cancers treated with adjuvant AC. Methods: Women with stage I/II breast cancer treated with adjuvant AC (A: 60 mg/m2, C: 600 mg/m2 on a 21-day schedule) between 1990 and 1995 were retrospectively identified through the BCCA pharmacy database and linked to the BCCA Breast Cancer Outcomes Unit database. A dose reduction was defined as a reduction of at least one of the chemotherapy agents by at least 25% in any given cycle. Dose delay was defined as a delay in delivering treatment by at least 5 days. Cases were classified into the following 4 cohorts; cohort 1: entire course of treatment delivered at full doses and on time; cohort 2: one single dose reduction or dose delay; cohort 3: more than one dose reduction or dose delay; cohort 4: = 2 cycles of chemotherapy delivered. No growth factor support was utilized in any cases. Results: 484 cases were retrospectively identified (cohort 1: n = 268; cohort 2: n= 88; cohort 3: n= 89; cohort 4: n= 39) with a median follow-up of 9.6 years. The four cohorts were well matched for most baseline prognostic factors except for slight imbalances in lymph node status (p=0.05) and adjuvant hormonal therapy (p=0.05). 55% of the entire cohort had node positive disease. Overall 45% of cases had a reduced DI delivered. However, there were no significant differences in 8 year RFS (p=0.94), BCSS (p=0.87) and OS (p=0.86) between the 4 cohorts. The 8 year outcomes for cohorts 1–4 respectively were: RFS (72%, 74%, 74%, 68%), BCSS (80%, 77%, 82%, 80%) and OS (78%, 76%, 80%, 77%). Conclusions: Although reductions in the DI of adjuvant AC chemotherapy for early stage breast cancer was common, it did not appear to significantly impact on clinical outcomes in this cohort of patients with stage I-II breast cancer. 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 | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 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".