ER-positive breast cancer
Breast cancer with estrogen and/or progesterone receptor expression on IHC. Endocrine therapy is the backbone of adjuvant and metastatic treatment per ESMO 2024 and NCCN 2024. Premenopausal women: first-line tamoxifen with or without ovarian function suppression; postmenopausal: aromatase inhibitors (letrozole, anastrozole, exemestane) for 5–10 years. In metastatic ER+ HER2-negative disease: aromatase inhibitor plus a CDK4/6 inhibitor (palbociclib, ribociclib, abemaciclib).
ICD-10 C505 drugs
Also known as: Hormone receptor positive breast cancer, HR+ breast cancer
Drugs used for this condition
- AAnastrozoleFirst line · Third-generation non-steroidal aromatase inhibitorFirst-line adjuvant endocrine therapy for hormone-receptor positive breast cancer in postmenopausal women per ESMO 2024 and NCCN 2024. Dose 1 mg once daily for 5–10 years. The ATAC trial showed superiority over tamoxifen in disease-free survival. Also used as first-line for metastatic disease in postmenopausal women combined with a CDK4/6 inhibitor.
- AEverolimusSecond line · mTOR kinase inhibitor – immunosuppressant and antineoplasticCombined with exemestane in metastatic ER+ HER2-negative breast cancer after non-steroidal aromatase inhibitor progression (letrozole, anastrozole) per ESMO 2024. Dose 10 mg daily. BOLERO-2 doubled progression-free survival (4.1 to 10.6 months).
- AExemestaneFirst line · Steroidal aromatase inhibitorsAdjuvant therapy of early ER+ breast cancer in postmenopausal women and treatment of metastatic disease. Per ESMO 2024 and Spanish SEOM 2023 exemestane is used as first-line or as a switch after 2–3 years of tamoxifen (TEAM, BIG 1–98). Dose 25 mg once daily after meals. Adjuvant duration – 5 years (with or without tamoxifen). In metastatic disease – until progression with switch to letrozole or fulvestrant. Alternatives – anastrozole, letrozole.
- ALetrozoleFirst line · Third-generation non-steroidal aromatase inhibitorFirst-line adjuvant endocrine therapy for hormone-receptor positive breast cancer in postmenopausal women per ESMO 2024 and NCCN 2024. Dose 2.5 mg once daily for 5–10 years. The BIG 1–98 trial showed superiority over tamoxifen in disease-free survival. In metastatic ER+ HER2-negative disease, first-line combined with a CDK4/6 inhibitor (palbociclib, ribociclib, abemaciclib) or fulvestrant.
- ATamoxifenFirst line · Selective estrogen receptor modulator (SERM)Drug of choice for adjuvant endocrine therapy of hormone-receptor positive breast cancer in premenopausal women (ESMO, NCCN). Dose 20 mg once daily for 5–10 years (the ATLAS trial showed a 10-year benefit over 5 in high-risk patients). For risk reduction in women at high risk (BRCA carriers, LCIS, DCIS) efficacy is shown in the NSABP P-1 and IBIS-I trials; this use is outside the registered indication.
How to read tiers A–F
Evidence tiers belong to the drug-indication pair, not to the drug as a whole: the same substance can be A for one condition and F for another.
- AStrong evidence – first or second line in international guidelines
- BRecommended in selected cases
- CStudy data contradict each other
- DBenefit not proven, no documented harm
- FDocumented harm, or risk without benefit