Breast Cancer Treatment Evolution Over the Past Decade: A Systematic Review of Differences in Standard Therapies Between China and the US and Future

Breast cancer, as one of the most common malignant tumors among women worldwide, has seen its treatment concepts undergo a transformative shift over the past decade from "broad-spectrum comprehensive therapy" to "precision subtype-based therapy." DengyueMed has been deeply engaged in the field of oncology treatment for many years, continuously monitoring global developments in breast cancer diagnosis and treatment. Through a systematic review of the treatment systems in China and the United States, it has been found that both countries, leveraging their respective advantages in healthcare systems and research efforts, exhibit common trends in the evolution of standard therapies. However, differences in population characteristics, distribution of medical resources, and other factors lead to variations in development pace.

I. Evolution and Development Trajectory of Standard Breast Cancer Therapies in China and the US Over the Past Decade

In terms of the macro evolution of treatment concepts, both China and the US have gradually abandoned the "one-size-fits-all" traditional treatment model, establishing individualized treatment principles centered on molecular subtyping. Specifically, the treatment pathways for the three major subtypes—HER2-positive, hormone receptor (HR)-positive, and triple-negative breast cancer (TNBC)—have become increasingly clear. Precision therapies such as targeted therapy and immunotherapy have gradually replaced some traditional chemotherapies, becoming mainstream treatment approaches. Regarding development pace, the US, with its leading clinical research capabilities and drug approval efficiency, often takes the lead in breakthroughs in the development and clinical application of new therapies. China, relying on its vast patient base and rapidly growing research strength, has accelerated the development of domestic innovative drugs while introducing international advanced therapies, achieving a gradual transition from "following" to "running alongside," particularly forming its own characteristics in precision therapy for certain targets.

The treatment evolution in specific subtypes better illustrates this trajectory. For HER2-positive breast cancer, the US began promoting the dual-target regimen of trastuzumab combined with pertuzumab in the early 2010s, increasing the pathological complete response (pCR) rate in neoadjuvant therapy from 30% to over 60%. China subsequently incorporated the dual-target regimen into its guidelines in 2018, gradually popularizing it in clinical practice. In HR-positive breast cancer treatment, both countries have established CDK4/6 inhibitors combined with endocrine therapy as the first-line gold standard for advanced disease, but the US offers more options in drug selection and treatment sequencing optimization. Triple-negative breast cancer has been a common treatment challenge for both countries, but the past decade has seen breakthroughs in immunotherapy. The US first approved pembrolizumab combined with chemotherapy for clinical use, and China has gradually incorporated immune combination regimens into its guidelines, significantly improving patient prognosis.

II. Overview of Milestone Events in Standard Breast Cancer Therapies in China and the US Over the Past Decade

Over the past decade, milestone events in breast cancer treatment have emerged intensively in both China and the US, driving continuous innovation in the diagnostic and treatment landscape. These events include approvals of key drugs and major updates to authoritative guidelines, outlining the trajectory of precision therapy development.

Milestone events in the US highlight its leadership in research innovation and guideline updates: In 2018, the US Food and Drug Administration (FDA) approved pertuzumab combined with trastuzumab + docetaxel for first-line treatment of advanced HER2-positive breast cancer, establishing the core status of dual-target therapy. In 2020, the FDA approved the CDK4/6 inhibitor palbociclib for adjuvant therapy in early HR-positive breast cancer, advancing precision therapy to earlier stages. In 2022, based on the DESTINY-Breast04 study, the FDA approved the ADC drug T-DXd for HER2-low expressing breast cancer, incorporating HER2-low populations into the anti-HER2 treatment landscape for the first time. In 2023, the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines formally defined criteria for HER2-low expression. In early 2025, the FDA approved T-DXd for HER2-ultralow expression indications, and the National Comprehensive Cancer Network (NCCN) guidelines recommended it as a first-line treatment for HR+/HER2- advanced breast cancer patients with visceral crises.

Milestone events in China reflect the development characteristics of "introduction and absorption + domestic innovation": In 2018, the National Medical Products Administration (NMPA) approved pertuzumab for marketing, ushering in the era of dual-target therapy for HER2-positive breast cancer. In 2020, the Chinese Society of Clinical Oncology Breast Cancer Guidelines (CSCO BC Guidelines) listed CDK4/6 inhibitors combined with endocrine therapy as the first-line preferred option for advanced HR-positive breast cancer. In 2024, the CSCO BC Guidelines added a section on "HER2-low expression" to standardize related diagnostic and treatment processes. In December 2025, the NMPA approved T-DXd for HER2-ultralow expression indications, making China one of the few countries globally to incorporate this indication into clinical application. At the same time, the "CBCS&CSOBO Guidelines Essentials (2025 Edition)" formally introduced the diagnostic and treatment concepts for HER2-ultralow expression, aligning with international guidelines.

III. Comparison of Current Optimal Breast Cancer Treatment Regimens Under Authoritative Guidelines in China and the US

Currently, the US NCCN Guidelines and China's CSCO BC Guidelines serve as the core references for breast cancer diagnosis and treatment in the two countries. Their recommendations for optimal treatment regimens share consensus but also exhibit detailed differences due to variations in medical environments, drug accessibility, and other factors. The following compares from the perspective of major subtypes:

In HR+/HER2- breast cancer treatment, both guidelines list CDK4/6 inhibitors combined with endocrine therapy as the first-line gold standard for advanced disease. The difference lies in the NCCN Guidelines (2025 v5), which further advances the treatment sequencing of T-DXd, recommending it as a first-line regimen for patients with visceral crises or endocrine-refractory disease, with the applicable population covering HER2-low and ultralow expression. China's CSCO BC Guidelines (2025) currently recommend T-DXd as the preferred second-line option, with potential advancement in sequencing pending further accumulation of clinical data on HER2-ultralow expression indications. In early adjuvant therapy, the US recommends AI + OFS for 5 years in premenopausal high-risk patients and extended AI treatment to 8-10 years in postmenopausal patients. China's guidelines stratify recommendations based on factors such as lymph node positivity and tumor grade, allowing simplification to TAM monotherapy for 5 years in low-risk patients.

In the HER2-positive breast cancer field, both guidelines recommend trastuzumab + pertuzumab dual-target combined with chemotherapy as the preferred regimen for early neoadjuvant and advanced first-line therapy. For treatment after trastuzumab resistance, the US NCCN Guidelines recommend options such as T-DXd, tucatinib + trastuzumab + capecitabine. China's CSCO BC Guidelines prioritize pyrotinib + capecitabine (a domestically innovative drug) and T-DXd, reflecting recognition of the clinical value of domestic drugs. In HER2-low/ultralow expression populations, both guidelines unanimously recommend T-DXd as the core treatment drug, but the NCCN Guidelines provide more detailed definitions for applicable populations, clarifying the interpretation standard for IHC 0+ (with membrane staining). China's guidelines use the term "HER2 IHC 0 (with membrane staining)," which is essentially consistent in definition.

In triple-negative breast cancer treatment, both guidelines recommend chemotherapy as the foundational approach. In early neoadjuvant therapy, the US NCCN Guidelines recommend AC sequential paclitaxel, with residual disease patients potentially receiving subsequent capecitabine adjuvant therapy. China's guidelines prioritize combination regimens including anthracyclines and taxanes (e.g., TAC, AT). In advanced treatment, the US guidelines recommend atezolizumab + nab-paclitaxel for patients with PD-L1 expression ≥1%, and PARP inhibitors like olaparib for BRCA-mutated patients. China's guidelines have gradually incorporated immune combination regimens and PARP inhibitors, but with stricter criteria for drug accessibility and population screening, emphasizing precision recommendations based on genetic testing data from domestic patients.

IV. Predictions for Future Trends in Breast Cancer Diagnosis and Treatment

Looking ahead to the next 5-10 years, breast cancer diagnosis and treatment will continue to advance toward "more precise, more efficient, and safer" directions. The synergy and competition in research between China and the US will further drive field development, with core trends summarized as follows:

First, further refinement of molecular subtyping. With the普及 of genetic testing technologies, subgroups such as HER2-ultralow expression and HR-low expression will receive more precise definitions. "Individualized subtyping" based on multi-omics features will replace current traditional subtype classifications, making treatment regimens more aligned with patients' tumor biological characteristics. At the same time, liquid biopsy technologies like circulating tumor DNA (ctDNA) will be widely applied in efficacy monitoring and recurrence warning, achieving "dynamic precision therapy."

Second, diversification and combination of precision drugs. ADC drugs will continue to be a research hotspot, with next-generation ADCs like Dato-DXd demonstrating efficacy in more subtypes, gradually forming an ADC drug matrix with "multi-target, multi-mechanism." Additionally, combinations of targeted therapy and immunotherapy, dual immunotherapy, and other regimens will be continuously optimized, particularly in the TNBC field, potentially breaking through current treatment bottlenecks and further improving patient survival rates.

Third, the trend toward "de-chemotherapy" in treatment concepts. In subtypes like HR-positive and HER2-positive, the combined application of highly effective precision drugs will gradually reduce the proportion of chemotherapy, even achieving "chemotherapy-free treatment" for some patients, significantly enhancing quality of life while ensuring efficacy. For early-stage patients, treatment regimens will focus more on "cure-oriented" approaches, using precise neoadjuvant therapy to achieve downstaging and breast conservation, improving patient survival benefits and quality of life.

Fourth, synergistic integration of diagnostic and treatment systems in China and the US. China will accelerate the development and internationalization of domestic innovative drugs, promoting the inclusion of clinical research data based on Chinese populations into international guidelines. The US may draw from China's experience in large-scale population screening and grassroots diagnosis and treatment普及 to optimize medical resource allocation. Cooperation between the two countries in multicenter clinical research, mutual recognition of drug approvals, and other areas will deepen, driving overall improvement in global breast cancer diagnosis and treatment levels.

V. Summary and Outlook

Over the past decade, standard breast cancer therapies in China and the US have undergone profound changes from "subtype-based therapy" to "precision subtyping + dynamic monitoring." Breakthroughs in precise targeting of HER2, widespread application of CDK4/6 inhibitors, and revolutionary advancements in ADC drugs have collectively driven significant improvements in patient survival rates. The US holds a leading position in research innovation and clinical translation due to its advantages in research and approval processes. China has achieved rapid catch-up in diagnosis and treatment levels through the path of "introduction and absorption + domestic innovation," with notable achievements particularly in domestic innovative drug development and guideline localization optimization.

Currently, the core treatment regimens in China-US guidelines have already formed broad consensus, but differences remain in treatment sequencing and drug selection details, which are objective reflections of factors such as medical resource distribution, drug accessibility, and population characteristics. In the future, with further development of molecular testing technologies and continuous iteration of precision drugs, breast cancer treatment will enter a new stage of "individualized precision medicine." Deep collaboration between China and the US in clinical research, drug development, and diagnostic and treatment standards will bring more treatment options to global breast cancer patients, ultimately achieving the core goals of "improving cure rates and enhancing quality of life." For China, it is necessary to continuously strengthen domestic research innovation capabilities, accumulate more high-quality local clinical data, promote the internationalization of diagnostic and treatment guidelines, and optimize medical resource allocation to make precision therapy benefit more grassroots patients, achieving comprehensive improvement in breast cancer diagnosis and treatment levels.