Editor’s Note: The 2026 National Breast Cancer Conference was held in Beijing from April 10–12, during which important updates to the Chinese Society of Clinical Oncology (CSCO) Breast Cancer Guidelines 2026 (CSCO BC Guidelines 2026) were officially released. At the meeting, Professor Kun Wang from Guangdong Provincial People’s Hospital presented and interpreted the latest updates in neoadjuvant and adjuvant treatment strategies for early breast cancer.To further clarify the key revisions in the updated guidelines, Oncology Frontier invited Professor Wang to provide an additional in-depth overview of the latest recommendations for neoadjuvant and adjuvant management of HER2-positive early breast cancer.
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Oncology Frontier: The 2026 edition of the CSCO BC Guidelines was officially released during this year’s National Breast Cancer Conference. Could you summarize the major updates in the neoadjuvant and adjuvant treatment recommendations for HER2-positive early breast cancer?
Professor Kun Wang: In the 2026 edition of the CSCO BC Guidelines, there are two major updates regarding neoadjuvant treatment for HER2-positive breast cancer.
First, based on studies such as NeoCARHP and HELEN006, the THP×4 regimen has been downgraded from a Category II recommendation to a Category III recommendation.
Second, based on data from the DESTINY-Breast11 (DB-11) study, a new regimen consisting of T-DXd followed sequentially by THP has been added to the Category III recommendations.
Importantly, the T-DXd→THP sequential regimen recently received conditional approval from China’s National Medical Products Administration (NMPA) for neoadjuvant treatment of adult patients with HER2-positive stage II (high-risk) or stage III breast cancer. Its inclusion in the updated guidelines further validates the DB-11 findings and establishes this strategy as an effective treatment option for patients with high-risk HER2-positive early breast cancer.
Regarding adjuvant therapy following neoadjuvant treatment, several updates have also been introduced:
- Because dual HER2 blockade with trastuzumab plus pertuzumab (HP) has become widely adopted, the guidelines no longer distinguish between patients who previously received H versus HP in the neoadjuvant setting.
- Within the Category I recommendations, the recommendation level for T-DM1 has been downgraded from Level 1A evidence to Level 2A evidence.
- Based on results from the DESTINY-Breast05 (DB-05) study, T-DXd has been newly incorporated into the Category II recommendations.
- In the Category III recommendations, sequential neratinib is no longer recommended.
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Oncology Frontier: What recent clinical evidence and unmet clinical needs drove these updates? In your opinion, how will these revisions influence real-world neoadjuvant treatment strategies for breast cancer patients?
Professor Kun Wang: Every regimen included in the guidelines is ultimately supported by robust clinical evidence.
The newly added T-DXd→THP sequential regimen in the Category III neoadjuvant recommendations for HER2-positive breast cancer is based on findings from the DESTINY-Breast11 study.
DB-11 included three treatment arms:
- Arm A: T-DXd monotherapy (N=286) Patients received eight cycles of T-DXd.
- Arm B: T-DXd→THP sequential therapy (N=321) Patients received four cycles of T-DXd followed by four cycles of THP.
- Arm C: ddAC→THP (N=320) Patients received four cycles of dose-dense doxorubicin plus cyclophosphamide (ddAC), followed by four cycles of THP, representing the conventional standard regimen.
The study results showed that the pCR rate in the eight-cycle T-DXd monotherapy arm was 43%, which was lower than the 56.3% pCR rate observed in the ddAC→THP arm.
However, the T-DXd→THP sequential arm achieved a pCR rate of 67.3%, representing an absolute improvement of 11.2% over the ddAC→THP arm. In addition, the T-DXd→THP regimen also demonstrated a favorable trend in event-free survival (EFS).
These results formed the basis for the inclusion of this regimen in the 2026 CSCO BC Guidelines.
In the adjuvant setting, the newly added Category II recommendation for T-DXd is supported by findings from the DESTINY-Breast05 study.
DB-05 was designed to evaluate the efficacy and safety of T-DXd versus T-DM1 as adjuvant therapy in high-risk HER2-positive early breast cancer patients who still had residual invasive disease after neoadjuvant treatment.
The results demonstrated that T-DXd significantly improved 3-year invasive disease-free survival (IDFS) compared with T-DM1.
Specifically:
- The 3-year IDFS rate was 92.4% in the T-DXd arm versus 83.7% in the T-DM1 arm.
- This represented an absolute benefit of 8.7% (HR 0.47; 95% CI 0.34–0.66; P<0.0001).
In practical terms, this means that T-DXd reduced the risk of disease recurrence and distant metastasis by 53% in patients with high-risk HER2-positive breast cancer.
Furthermore, compared with T-DM1, T-DXd improved 3-year disease-free survival (DFS) by 8.8% (92.3% vs 83.5%; HR 0.47; 95% CI 0.34–0.66; P<0.0001), demonstrating highly encouraging survival benefits.
These findings ultimately supported the incorporation of T-DXd into the 2026 CSCO BC Guidelines and provide clinicians with a more effective therapeutic option for high-risk HER2-positive early breast cancer patients.
