Abstract A081: Real-world treatment patterns and clinical outcomes in patients with HER2+ metastatic breast cancer receiving systemic therapy in Ontario, Canada
Bibliographic record
Abstract
Abstract Background: Real-world data on treatment patterns and prevalence of brain metastases in patients with HER2+ metastatic breast cancer (mBC) are limited. This study described treatment patterns and clinical outcomes among patients with HER2+ mBC in Canada. Methods: This was a retrospective chart review of adult patients diagnosed with de-novo or recurrent HER2+ mBC between Jan 1, 2014 and Mar 1, 2021 (prior to wide availability of new treatments) at Sunnybrook Research Institute and Sinai Health, two large BC treatment centres in Canada. Data on patient characteristics and treatment regimens were extracted. Treatment patterns, time to next treatment (TTNT; as a proxy for progression-free survival), and presence of brain metastases were assessed in the first-line (1L), second-line (2L), and third-line (3L) settings. TTNT analyses used Kaplan-Meier methodology to account for censoring. Results: Of 121 patients with HER2+ mBC, the median (IQR) age was 54.0 (17.0) years. 38.0% of patients had de-novo disease and 62.0% had recurrent mBC; 12 (9.9%) had brain metastases at the time of mBC diagnosis. Systemic therapies generally aligned with Canadian funded regimens for 1L (101 of 121 patients [83.5%] received trastuzumab + pertuzumab ± chemotherapy ± subsequent endocrine therapy; 8/121 [6.6%] received endocrine therapy only) and 2L (50/68 [73.5%] received T-DM1 ± endocrine therapy; 9/68 [13.2%] received endocrine therapy only). However, treatment patterns were heterogeneous in the 3L setting (14/46 [30.4%] received anti-HER2 TKI + chemotherapy ± trastuzumab; 10/46 [21.7%] received endocrine therapy only; 10/46 [21.7%] received chemotherapy). Median (95% CI) TTNT in months was 21.4 (16.1, 27.2) in 1L, 11.0 (8.5, 16.5) in 2L, and 8.7 (5.4, 15.6) in 3L. Median (IQR) follow-up was 29.9 (25.2) months. In total, 57 patients (47.1%) were diagnosed with brain metastases during the study period (17 pre-1L, 24 post-1L/pre-2L, 6 post-2L/pre-3L) and of these, 73.7% received radiation therapy. Conclusions: In patients with HER2+ mBC in Canada, 3L treatment patterns are heterogeneous, median TTNT is <1 year, and almost half develop brain metastases. These data from two large treating centres in Ontario suggest a high unmet need for more effective treatment regimens in later lines of therapy, particularly 3L, for patients with HER2+ mBC. Citation Format: Katarzyna J Jerzak, Ruth Moulson, Ling-I Hsu, Chris Lenhu, Dhivo Krishnathasan, Jessica Weiss, Christine Brezden-Masley. Real-world treatment patterns and clinical outcomes in patients with HER2+ metastatic breast cancer receiving systemic therapy in Ontario, Canada [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr A081.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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 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".