Six months of adjuvant trastuzumab,
does it really help with Noninferior 4-year disease-free survival versus 12 months in HER2-positive early breast cancer?
research showsThe grade is B. In 4,088 PERSEPHONE participants, 4-year disease-free survival was 89.4% versus 89.8%, an absolute difference of -0.4 points. HR 1.07 (90% CI 0.93 to 1.24) stayed within the prespecified HR margin of 1.32. Cardiotoxicity-related stopping fell from 8% to 3%.
ads claimThis does not prove that both durations are identical. It shows that the result stayed within a prespecified acceptable loss boundary.
Useful facts when choosing a product
- Six months entails fewer infusions, visits, and lower drug cost than 12 months.
- Cardiotoxicity-related stopping was 3% versus 8%.
- Verdict 2902 is B with 76 points and shares the duration-shortening concept, but concerns oxaliplatin neuropathy in colorectal cancer.
What the research actually shows
PERSEPHONE randomized 4,088 patients. Its margin allowed no more than a 3-point loss from an assumed 80% 4-year DFS, corresponding to HR 1.32. Four-gate bias review: ① defect: noninferiority design; ② listed item: noninferiority design; ③ source: 'non-inferiority limit as no worse than 3% below the standard arm,' with CI upper bound 1.24 within 1.32; ④ avoidable: yes, a superiority framework could have been used, so it counts once. Survival censoring was not counted as dropout, and cardiac stopping was an outcome rather than loss to follow-up. NIHR HTA funded the trial.
Why this is classified as B (76)
A large publicly funded hard-outcome RCT met its margin, but reliance on one noninferiority trial gives B with 76 points.
Counterpoint. Noninferiority is not proof of identity and does not automatically replace the 12-month standard.
Rejudgment record. New verdict — Large publicly funded hard-outcome RCT meeting a prespecified noninferiority margin, with the noninferiority-design limitation counted
| Endpoint | H | Hard endpoint - actual events such as death |
| Replication | R1 | Single confirmatory trial |
| Independence | I2 | Decisive evidence is publicly or non-profit funded |
| Effect size | E+ | Meets the clinically important threshold |
The scoring table and the verdict agree (B).
Sub-claim grades by effect
This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.
| Effect (sub-claim) | Grade | Basis |
|---|---|---|
| Noninferior 4-year disease-free survival | B | The CI upper bound of 1.24 stayed within the 1.32 HR margin. |
| Reduced cardiac-toxicity burden | B | Cardiac-toxicity stopping fell from 8% to 3%. |
Cross-check — AI research and Codex final gate
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Study 1 | Multicenter phase 3 randomized noninferiority trial | 4,088 | UK NIHR HTA public funding | 4-year disease-free survival | 89.4% versus 89.8%, absolute difference -0.4 points; HR 1.07 (90% CI 0.93 to 1.24), margin 1.32; cardiac-toxicity stopping 3% versus 8%. | Pivotal large hard-outcome evidence |
Receipt — 1 References
All 1 cited sources were verified for existence at the original page (as of 2026-08-26).
Final verification and publication gate: Codex · Verification cutoff: 2026-08-26 · Corrections: none
Cite this verdict
[Chamgap] Benefit of 6-Month Trastuzumab for Noninferior 4-Year Disease-Free Survival in HER2-Positive Early Breast Cancer — Evidence Grade B·76. 1 cited sources checked. Source: https://chamgap.com/en/verdicts/womens/six-month-trastuzumab-her2-early-breast-cancer-dfs/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.