Letter to the Editor: Radiation for Prior DCIS is a Risk Factor for Death From Invasive Breast Cancer
Bibliographic record
Abstract
We read with interest the article by Li et al 1 regarding the impact of prior radiotherapy (RT) for ductal carcinoma in situ (DCIS) on the prognosis of women with invasive breast cancer.The authors report that the risk of breast cancer mortality following invasive breast cancer among women with a prior diagnosis of DCIS is 1.7 times higher if the DCIS was treated with lumpectomy 1 RT versus lumpectomy alone (adjusted hazard ratio [HR], 1.70; 95% CI, 1.18-2.45;P5.005).The authors suggest that this finding may have implications for the use of RT in the initial treatment of DCIS.However, we propose another interpretation.Treatment of DCIS with lumpectomy 1 RT, compared with lumpectomy alone, is associated with a large reduction in the risk of subsequent ipsilateral invasive breast cancer but little or no reduction in the risk of breast cancer mortality.2,3 In SEER, we compared the risks of ipsilateral invasive recurrence and of breast cancer-specific mortality among patients with DCIS treated with lumpectomy 6 RT using one-to-one matching.2 In this analysis (including 29,465 propensitymatched pairs of patients), the use of RT after lumpectomy was associated with a 36% reduction in the 15-year risk of ipsilateral invasive breast cancer (8.1% vs 5.2%; absolute reduction of 2.9%) and a small reduction in the risk of breast cancer mortality (2.0% vs. 1.8%; absolute reduction of 0.2%).The ratio of deaths to recurrences increased from 0.25 in patients treated with lumpectomy alone to 0.35 in patients treated with lumpectomy 1 RT; therefore, for every 10,000 patients treated with lumpectomy alone, we would expect approximately 810 ipsilateral invasive recurrences and 200 breast cancer deaths, whereas for every 10,000 patients treated with lumpectomy 1 RT, we would expect 520 ipsilateral invasive recurrences and 180 breast cancer deaths.These numbers correspond to a HR for death associated with RT of approximately 1.40, suggesting that the HR of 1.70 generated by Li et al 1 may in part be explained by a reduction in the number of cases (ie, patients with recurrence after DCIS) but no reduction in the number of deaths.
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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 | 0.003 | 0.024 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.014 | 0.015 |
| Insufficient payload (model declined to judge) | 0.005 | 0.005 |
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".