Abstract P4-16-06: Radiotherapy to the Primary Tumor Is Associated with Improved Survival in Stage IV Breast Cancer
Bibliographic record
Abstract
Abstract Background: In patients found to have metastatic disease at the time of breast cancer diagnosis, the role of local therapy is undefined. Numerous retrospective analyses have suggested that surgery and/or external beam radiotherapy (EBRT) directed at the primary tumor may improve overall survival (OS). All these analyses, however, are subject to significant selection bias. The current retrospective analysis of a large registry dataset attempts to limit the effect of this bias. Methods: The study population consisted of women in the Surveillance, Epidemiology, and End Results (SEER) program database diagnosed with stage IV breast cancer between 1988 and 2009. Only those patients for whom surgery to the primary tumor was recommended but was not undertaken (due to patient refusal or other uncategorized reasons) were included. In this population of patients deemed candidates for surgery, the association between receipt of primary tumor-directed EBRT and overall survival was studied. Descriptive statistics were used to characterize the study population. OS was estimated using the Kaplan-Meier (KM) method. Univariate and multivariate Cox regression were used to identify factors associated with OS. Results: A total of 3,529 cases were analyzed. EBRT was received in 768 cases. Median age at diagnosis was 68 years (IQR, 56–79 years). Median follow-up by reverse KM estimate was 98 months (range, 0–252 months). On univariate analysis, EBRT was associated with improved OS (hazard ratio 0.80, 95% CI 0.74–0.87, p < 0.001). 1-year, 3-year, and 5-year OS was 56.9%, 24.2%, and 10.7% respectively in those receiving EBRT and 44.3%, 16.6%, and 7.2% respectively in those not receiving EBRT. Median OS in those receiving EBRT was 15 months compared to 7 months in those not receiving EBRT. In a multivariate Cox model taking into account receipt of EBRT, age at diagnosis, year of diagnosis, ethnicity, number of primary cancers, estrogen and progesterone receptor status, histologic grade, and size of primary tumor, EBRT remained significantly associated with improved survival (hazard ratio 0.86, 95% CI 0.76–0.97, p = 0.011). Conclusions: In a population of women presenting with metastatic breast cancer, all of whom were deemed candidates for surgery to the primary tumor but who did not undergo surgery, receipt of EBRT was associated with improved OS. The observed 8-month absolute difference in median OS is clinically significant. This analysis could not account for performance status, extent of metastatic disease, co-morbidities, use of systemic therapies, and other potentially confounding factors. Only randomized studies, such as the Eastern Cooperative Oncology Group E2108 trial currently underway, will be able to definitively assess the value of local therapy directed at the primary tumor in this setting. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-16-06.
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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 | 0.000 | 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) | 0.006 | 0.001 |
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".