Overall survival comparison in patients with and without brain metastases treated with osimertinib for metastatic EGFR mutation positive non-small cell lung cancer (NSCLC).
Bibliographic record
Abstract
e21216 Background: With the development of Epidermal Growth factor receptor (EGFR) tyrosine kinase inhibitors such as Osimertinib, the landscape of lung cancer treatment and outcomes has changed. We aimed to describe the outcomes of patients treated with Osimertinib who have brain metastasis compared to those without brain metastases. Methods: This study involved patients diagnosed with metastatic non-small cell lung cancer (NSCLC) with EGFR mutation, from January 2010 to December 2018, who had treatment with Osimertinib at a dose of 80 mg daily. Retrospective data was collected through the electronic medical records from Sunnybrook Health Sciences Centre. Descriptive statistics were used to summarize the population characteristics. The log rank test was used to compare the survival distributions. Results: A total of 56 patients were included, the mean age at initial diagnosis was 63 years (range 27 – 85 years). Overall, 82.2% of this patient population received Osimertinib in 2nd line setting. A total of 50% (n = 28) had brain metastasis, and14.3% (n = 8) had leptomeningeal metastasis. Of the patients with brain metastasis, 14.3% (n = 4) had brain surgery. All patients with brain metastasis received central nervous system (CNS) radiation. With respect to radiotherapy modalities, 67.9% (n = 19) of patients with brain metastasis received gamma knife radiation, 42.85% (n = 12) were treated with stereotactic radiosurgery (SRS), and whole brain radiation was given to 57.1% (n = 16). Of those with brain metastasis, equal numbers of patients, 46.4% (n = 13), had EGFR mutations with exon 19-deletion and exon 21-L858R, 7.1% (n = 2) had unknown gene location EGFR mutation. The median OS for patients without brain metastasis was 38.6 months (95% confidence interval [CI] 37.5 – 39.8 months], compared to 35.9 months (95% [CI] 28.3 – 43.5 months] for those with brain metastasis ; log Rank (Mantel-Cox) p = 0.874. The median OS for patients diagnosed with leptomeningeal metastasis was 21 months (95% [CI] 2.9 – 39.0 months); log rank (mantel-cox). When brain metastasis was examined by EGFR mutation sub-groups, the median OS for patients with EGFR-exon 19-deletion was 26.4 months (95% CI [14.3 – 38.4 months], compared to 36.8 months, 95% CI [34.3 – 39.2 months] for those with EGFR-Exon 21-L858R; log Rank (Mantel-Cox) p = 0.49. Conclusions: Although there is an equivalent prevalence of brain metastasis between the two NSCLC EGFR mutation populations, in unadjusted analyses, no difference in OS was seen between patients with brain metastases compared to those without brain metastases. However, in the small number of patients with leptomeningeal disease, survival was shorter and a larger population should be studied to further explore this finding.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".