Clinical-pathologic characteristics of true interval and screen-detected breast cancer among participants in a Canadian breast screening program: A nested case-control study
Bibliographic record
Abstract
638 Background: The interpretation of clinical and biologic differences between screen-detected and interval breast cancers has been limited by the failure to control for factors known to influence breast cancer biology, such as age at diagnosis, as well as for differences in recommended screening intervals between age groups. Methods: A case-control study nested within the participants of the population-based Nova Scotia Breast Screening Program diagnosed between ages 40–69 in the period 1991–2006 was performed. Interval cases were selected as having developed after a negative screen and prior to the recommended next screen and were validated by blinded review of the pre-diagnosis screening mammogram by 3 mammographers, 2 of whom had to agree that the screening exam was negative. Screen-detected cases were matched to intervals on a 2:1 basis by 5-year age group and recommended screening interval (40–49 yo, annual; 50–69 yo + family history, annual; 50–69 yo - family history biennial). Results: 240 interval cancers were identified of which 38% were grade 3 lesions and 31.7% had LVI. Selected comparisons to controls are presented in Table 1. For those with currently available data, ER/PR/HER2 results (intervals vs screen-detected) were; ER+ 73% vs 78.5%, PR+ 65.4% vs 72.5%, HER2+ 17% vs 26.7%. Conclusions: Controlling for age and screening interval, interval breast cancers are significantly larger and significantly more frequently node-positive at diagnosis compared to screen-detected cancers. They are also more likely to be of lobular histology and have a triple-negative phenotype. A Comparison of Selected Variables between Interval Cases and Controls Matched for Age at Diagnosis and Screening Interval Age at diagnosis 40–49 50–69 50–69 Recommended screening interval 1yr 1yr 2yr Cancer detection Interval Screen Interval Screen Interval Screen Sample size 37 74 41 82 162 324 Invasive disease (%) 100 75.7 95.1 79.3 91.3 78.7 * for all age groups Size-mms (mean) 23.3 13.2 17.8 12.1 18.9 11.5 * for all age groups Positive lymph nodes (%) 46 20.3 31.7 20.7 37.6 15.1 *40–49 and 50–69, 2yr interval Triple negative (%) 12.5 0 16.7 11.1 23.4 5.3 Invasive lobular (%) 8.1 4 12.2 6.1 7.4 7.1 * p < 0.05 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 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 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".