Evidence-Based Supplement & Herb Guides

CA 27.29 Test for Breast Cancer: Tumor Marker Levels, Monitoring, and Recurrence

CA 27.29 breast cancer testing explained: reference range, high and normal results, serial trends, metastatic monitoring, recurrence limits, and follow-up guidance.

CA 27.29 is a blood tumor marker that measures a circulating form of the MUC1 protein, which can be released by breast cancer cells...

Circulating Tumor DNA Test for Breast Cancer: MRD, Recurrence, Mutation Detection, and Monitoring

Breast cancer ctDNA testing explained: MRD, recurrence risk, mutation detection, liquid biopsy, treatment selection, false negatives, and current monitoring guidance.

A circulating tumor DNA (ctDNA) test looks for fragments of DNA released by cancer cells into the bloodstream. In breast cancer, ctDNA has two...

EndoPredict Test: Breast Cancer Recurrence Risk and Genomic Prognosis

EndoPredict explained: EP and EPclin scores, the 3.3 cutoff, distant recurrence risk, genomic prognosis, chemotherapy decisions, and test limitations.

EndoPredict is a gene-expression test used in selected estrogen receptor-positive, HER2-negative early breast cancers to estimate the risk of distant recurrence. It measures expression...

ESR1 Mutation Test for Breast Cancer: Hormone Resistance Marker, Recurrence, and Mutation Meaning

ESR1 mutation testing explained: hormone resistance, ctDNA detection, positive and negative results, oral SERDs, recurrence limits, and 2026 treatment guidance.

An ESR1 mutation test looks for acquired changes in the gene that encodes estrogen receptor alpha, a major driver of hormone receptor-positive breast cancer....

Estrogen Receptor (ER) Test: Breast Cancer Hormone Receptor Status, Positive Score, and Meaning

Learn how the estrogen receptor (ER) breast cancer test is scored, what ER-positive, ER-low, and ER-negative results mean, and how ER status guides treatment.

An estrogen receptor (ER) test shows whether breast cancer cells contain estrogen receptor protein and how many tumor-cell nuclei stain for it. Pathologists usually...

HER2 Breast Cancer Test: IHC, FISH, HER2 Score, Amplification, and HER2-Low Status

Understand HER2 breast cancer testing, including IHC scores, FISH amplification, positive and negative results, HER2-low, HER2-ultralow, and treatment meaning.

A HER2 breast cancer test determines how much HER2 protein a tumor expresses and, when needed, whether the HER2 gene is amplified. The result...

HER2 FISH Test for Breast Cancer: Gene Amplification, HER2 Status, and Result Meaning

Learn how the HER2 FISH test measures gene amplification, how HER2/CEP17 ratio and copy number define ISH groups, and what positive or negative results mean.

A HER2 FISH test examines breast cancer cells for extra copies of the HER2 gene, also called ERBB2. It is most often used when...

HER2 IHC Test for Breast Cancer: Protein Expression Score, HER2-Low, and Result Meaning

Learn how HER2 IHC scores 0, 1+, 2+, and 3+ are interpreted, what HER2-low and ultralow mean, when FISH is needed, and how results guide breast cancer therapy.

A HER2 IHC test measures HER2 protein on the surface of breast cancer cells and reports a score of 0, 1+, 2+, or 3+....

HER2-Low Breast Cancer Test: IHC Score, HER2 Expression, and Tumor Classification

Learn how HER2-low breast cancer is identified by IHC 1+ or IHC 2+/ISH-negative results, how scores are interpreted, and why HER2 expression can affect treatment.

A HER2-low breast cancer test is not a separate laboratory test. It is a way of interpreting the amount of HER2 protein seen on...

Hormone Receptor-Positive Breast Cancer Biomarker Panel: ER, PR, ESR1, PIK3CA, and Tumor Profile

A hormone receptor-positive breast cancer biomarker panel is not one universal laboratory panel. It is the combined set of pathology and molecular tests used...

Ki-67 Breast Cancer Test: Proliferation Score, Tumor Grade, and Prognosis Meaning

Learn what a Ki-67 breast cancer score measures, how percentages relate to proliferation and tumor grade, which cutoffs are useful, and why results need clinical context.

The Ki-67 breast cancer test estimates how actively tumor cells are dividing. A pathologist stains tumor tissue for the Ki-67 protein and reports the...

MammaPrint Test: Breast Cancer Recurrence Risk and Genomic Risk Score

Learn how the MammaPrint 70-gene breast cancer test classifies genomic recurrence risk, what Low, High, and UltraLow results mean, and how it can inform chemotherapy decisions.

MammaPrint is a 70-gene expression test used in selected people with early-stage invasive breast cancer to estimate the risk of distant recurrence. It analyzes...

Mammostrat Test: Breast Cancer Prognosis and Risk Classification

Mammostrat was a five-protein breast cancer prognosis test that classified low, moderate, and high recurrence risk; learn how it worked, what old results mean, and why it is no longer used.

Mammostrat was a five-marker immunohistochemistry test developed to estimate recurrence risk in early breast cancer, especially estrogen receptor-positive disease treated with endocrine therapy. It...

Oncotype DX Breast Recurrence Score Test: Recurrence Risk, Genomic Score, and Prognosis

Oncotype DX measures 21 tumor genes to produce a Breast Recurrence Score from 0 to 100; learn how node status, age, menopause, and pathology shape recurrence risk and chemotherapy decisions.

The Oncotype DX Breast Recurrence Score test is a tumor gene-expression assay used mainly in early-stage, hormone receptor-positive, HER2-negative invasive breast cancer. It analyzes...

PALB2 Test for Breast Cancer: Cancer Risk, DNA Repair, Variant Meaning, and Family Risk

PALB2 testing can reveal inherited DNA-repair variants linked to breast and family cancer risk; learn what positive, negative, and uncertain results mean and how they affect screening.

A PALB2 test looks for inherited changes in the PALB2 gene that can raise the risk of breast cancer and several other cancers. PALB2...

PD-L1 Test for Breast Cancer: Immunotherapy Marker, CPS Score, and Expression Meaning

PD-L1 testing in breast cancer uses tumor-tissue immunohistochemistry and CPS scoring; learn why CPS 10 matters in metastatic TNBC and why early-stage treatment is different.

The PD-L1 test for breast cancer is an immunohistochemistry test used mainly to help determine whether certain patients with advanced triple-negative breast cancer may...

PIK3CA Mutation Test for Breast Cancer: Mutation Status, PI3K Pathway, and Result Meaning

PIK3CA testing detects PI3K-pathway mutations in breast cancer; learn how tissue and ctDNA results are interpreted and how positive findings can guide targeted therapy.

A PIK3CA mutation test looks for tumor DNA changes that activate the PI3K signaling pathway, one of the most commonly altered growth pathways in...

Progesterone Receptor (PR) Test: Breast Cancer Hormone Receptor Status, Positive Score, and Meaning

The progesterone receptor test measures PR nuclear staining in breast cancer; learn the 1% positive threshold, how PR is interpreted with ER, and what low or negative results mean.

The progesterone receptor, or PR, test is an immunohistochemistry test performed on breast cancer tissue to determine whether tumor-cell nuclei contain progesterone receptor protein....

Prosigna PAM50 Test: Breast Cancer Subtype, Recurrence Risk, and Molecular Classification

Prosigna PAM50 measures breast tumor gene expression to report molecular subtype and a 0–100 Risk of Recurrence score; learn how nodal status and menopause shape interpretation.

The Prosigna PAM50 test is a gene-expression assay used in selected patients with early-stage, hormone receptor-positive breast cancer to estimate the risk of distant...

Triple-Negative Breast Cancer Biomarker Test: ER, PR, HER2, PD-L1, BRCA, and Tumor Profile

A triple-negative breast cancer biomarker workup starts by proving what the tumor does not express: estrogen receptor (ER), progesterone receptor (PR), and HER2 at...