Breast Cancer

What researchers are actively studying

Several major trials are expanding the use of existing agents and testing new combinations. A Phase 3 study (NCT05827081) is evaluating ribociclib plus endocrine therapyTreatments that reduce or block hormones that fuel certain cancers.Click for full explanation → in early breast cancer. Another Phase 3 trial (NCT06058377) is adding durvalumab, an immune checkpoint inhibitor, to standard chemotherapyDrugs that kill rapidly dividing cells, including cancer cells.Click for full explanation → for Stage II to III breast cancer. A Phase 3 study is comparing HRS-8080 combined with the CDK4/6 inhibitor dalpiciclib against fulvestrant plus dalpiciclib for advanced breast cancer resistant to prior endocrine therapyTreatments that reduce or block hormones that fuel certain cancers.Click for full explanation →.

For TNBC, a Phase 1 trial (NCT05673200) is adding ASTX727, a DNA methylation inhibitor, to paclitaxel and pembrolizumab in metastatic disease. Researchers are also investigating metformin as a means of enhancing gamma-delta T cell immune function against TNBC, and albumin nanoparticle systems to improve platinum drug delivery. The blood-brain barrier and immune evasion in brain metastases are under active study. For HER2A protein that promotes cell growth — overexpressed in some breast and stomach cancers.Click for full explanation →-positive metastatic disease, a Phase 1 trial (NCT05378464) is testing adoptive T cell therapy combined with a dendritic cell vaccine and trastuzumab. On the prevention side, Phase 2 trials are evaluating low-dose tamoxifen with or without omega-3 fatty acids, and comparing acolbifene to low-dose tamoxifen in high-risk premenopausal women.

Where the evidence stands

The most mature evidence supports CDK4/6 inhibitors in HR-positive, HER2A protein that promotes cell growth — overexpressed in some breast and stomach cancers.Click for full explanation →-negative advanced disease, where multiple Phase 3 trials have established them as standard care. Fulvestrant combinations and alpelisib in PIK3CA-mutated disease also rest on Phase 3 findings. HER2A protein that promotes cell growth — overexpressed in some breast and stomach cancers.Click for full explanation →-directed therapies, including antibody-drug conjugates, have strong Phase 3 data across HER2A protein that promotes cell growth — overexpressed in some breast and stomach cancers.Click for full explanation →-positive and HER2A protein that promotes cell growth — overexpressed in some breast and stomach cancers.Click for full explanation →-low settings. In TNBC, pembrolizumab combinations and sacituzumab govitecan are similarly Phase 3 supported. Moving into earlier stages, the role of CDK4/6 inhibitors and immunotherapyTreatments that use the body's immune system to fight cancer.Click for full explanation → is still being established through ongoing Phase 3 trials. Novel strategies such as metformin-enhanced immune cell therapy and nanoparticle drug delivery remain at preclinical or early Phase 1 stages. MicroRNA-based diagnostic markers, including miR-223, miR-326, and miR-429, are under investigation but not yet in clinical use.

What this means for people affected

Breast cancer treatment has become increasingly precise, with subtype-specific therapies offering meaningful options across HR-positive, HER2A protein that promotes cell growth — overexpressed in some breast and stomach cancers.Click for full explanation →-positive, and triple-negative categories. Targeted treatments are now available for people with specific molecular profiles, including PIK3CA mutationsA change in DNA sequence that can drive cancer development.Click for full explanation → and BRCA1Genes whose mutations significantly raise the risk of breast and ovarian cancers.Click for full explanation →/2 variants. Research is actively expanding the reach of immunotherapyTreatments that use the body's immune system to fight cancer.Click for full explanation → into earlier disease stages and exploring new combinations for TNBC and brain metastases. Risk-reducing mastectomy is a documented option for people with high-risk BRCA1Genes whose mutations significantly raise the risk of breast and ovarian cancers.Click for full explanation →/2 variants. Equitable access to established treatments remains an important consideration: research from lower-income countries and studies on adherence disparities highlight that geography, language, and insurance status can affect outcomes.