References

Sources cited throughout this research project, formatted in APA-style. All sources are reputable U.S. medical and government organizations.

1. [1]

   National Cancer Institute. (n.d.). Metastatic breast cancer treatment. U.S. Department of Health and Human Services, National Institutes of Health.

   https://www.cancer.gov/types/breast
2. [2]

   American Cancer Society. (n.d.). Breast cancer HER2 status. American Cancer Society.

   https://www.cancer.org/cancer/types/breast-cancer/understanding-a-breast-cancer-diagnosis/breast-cancer-her2-status.html
3. [3]

   American Cancer Society. (n.d.). Targeted drug therapy for breast cancer. American Cancer Society.

   https://www.cancer.org/cancer/types/breast-cancer/treatment/targeted-therapy-for-breast-cancer.html
4. [4]

   National Cancer Institute. (n.d.). Breast cancer prevention (PDQ®)–patient version. U.S. Department of Health and Human Services, National Institutes of Health.

   https://www.cancer.gov/types/breast/patient/breast-prevention-pdq
5. [5]

   National Cancer Institute. (n.d.). Breast cancer diagnosis. U.S. Department of Health and Human Services, National Institutes of Health.

   https://www.cancer.gov/types/breast/diagnosis
6. [6]

   National Cancer Institute. (n.d.). Tumor markers in common use. U.S. Department of Health and Human Services, National Institutes of Health.

   https://www.cancer.gov/about-cancer/diagnosis-staging/diagnosis/tumor-markers-list
7. [7]

   U.S. Food and Drug Administration. (2025, December). FDA approves fam-trastuzumab deruxtecan-nxki with pertuzumab for HER2-positive metastatic breast cancer. U.S. Food and Drug Administration.

   https://www.fda.gov/drugs/resources-information-approved-drugs
8. [8]

   U.S. Preventive Services Task Force. (2024). Breast cancer: Screening — final recommendation statement. USPSTF.

   https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/breast-cancer-screening