Abstract P3-12-02: Intraoperative radiotherapy outcomes in early-stage breast cancer: A study in elderly Canadian women
Bibliographic record
Abstract
Abstract Objective. Breast-conserving therapy with external beam radiotherapy (EBRT) is currently the standard of care for women with early breast cancer. Our aim was to determine if early-stage breast cancers treated with lumpectomy and primary intraoperative radiotherapy (IORT) have comparable local recurrence rates. This is the first study examining the Canadian experience with IORT. Methods. Patients who underwent breast-conserving therapy with pre-pathology IORT between 2007- 2017 were retrospectively identified. The primary outcome measure was ipsilateral breast tumor recurrence (IBRT). A time to event analysis was performed; Kaplan-Meier estimates report the fraction of patients living free of recurrence. Secondary outcomes included acute and chronic wound complications. Results. 106 patients with a median age of 70 (IQR 65-75) were included. Median follow-up was 33 months. The majority of patients had screen-detected (94.3%), estrogen-receptor positive (96.2%), HER2neu negative (93.4%), invasive ductal carcinomas (92.5%). Only 50 (47.6%) were prescribed adjuvant endocrine blockade. IBTR occurred in 5 (4.7%) patients. Five and ten-year local recurrence-free rates were 0.95 and 0.81, respectively. The superficial skin infection rate was 9.4%. Acute symptomatic seromas occurred in 23 (21.7%), while only 10 (9.4%) persisted chronically. Conclusion. In this cohort of Canadian post-menopausal women treated with breast-conserving surgery and IORT, the IBTR approached 5%. Despite selection of low-risk patients, the local recurrence rate is higher than what is reported in the literature with EBRT. The low rates of prescribed adjuvant systemic therapy may have contributed to this outcome. Citation Format: Elmi M, Tigert A, Escallon J, Zagorski B, Leong W, Vranic M, Fyles A, Vitkin A, Cil T, McCready D. Intraoperative radiotherapy outcomes in early-stage breast cancer: A study in elderly Canadian women [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-12-02.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.004 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".