Breast cancer, Intrinsic subtypes of breast cancer, Uncategorized

Intrinsic molecular subtypes of breast cancer

From the National Cancer Institute
http://visualsonline.cancer.gov/details.cfm?imageid=2289

Breast cancer cells


Classification and prognosis of invasive breast cancer: from morphology to molecular taxonomy
http://www.nature.com/modpathol/journal/v23/n2s/full/modpathol201033a.html

This article is quite easy to follow. It explains that newer techniques use gene expression profiling to identify certain molecular subtypes of breast cancer. This identification will help clinicians to better assess prognosis, determine treatment options and evaluate response to therapy.

Gene expression profiling is a way of measuring the activity of thousands of genes at once.
http://en.wikipedia.org/wiki/Gene_expression_profiling

Traditionally, the article explains that in order to decide which therapy would be best for the patient, clinicians look at the patient and categorize them according to:

1. Patient age
2. Axilla lymph node status
3. Histological features
4. Hormone receptor status
5. HER2 status

HER2 is the name of a protein that can be found on some types of cancer cells. If this finding is positive, then the tumor may grow more quickly.
http://www.macmillan.org.uk/Cancerinformation/Cancertypes/Breast/Symptomsdiagnosis/HormoneandHER2receptors/HER2andbreastcancer.aspx

The pathology report will show whether or not the cancer cells have receptor cells for estrogen and progesterone:

1. Hormone receptor-positive
2. Hormone receptor-negative
http://www.breastcancer.org/symptoms/diagnosis/hormone_status

In the table shown in the same article above, three main subtypes are described:
1. Luminal
2. Her2
3. Basal
http://www.nature.com/modpathol/journal/v23/n2s/fig_tab/modpathol201033t1.html

The next table in the same article shows:
Immunophenotyping to approximate molecular subtype using six biomarkersa
http://www.nature.com/modpathol/journal/v23/n2s/fig_tab/modpathol201033t2.html#figure-title

– Immunophenotyping is a technique used to study the protein expressed by cells –

There are five tumor subtypes of breast cancer listed in this article:

Phenotypic and molecular characterization of the claudin-low intrinsic subtype of breast cancer
http://breast-cancer-research.com/content/12/5/r68

1.Luminal A
2. Luminal B
3. HER2-enriched, basal-like and claudin-low
4. Basal-like
5. Claudin-low

– This article lists the above 5, and also says normal breast is a category, and thus names 6 subtypes.

Molecular biology in breast cancer: intrinsic subtypes and signaling pathways.
http://www.ncbi.nlm.nih.gov/pubmed/22178455

Wikipedia lists 7 types:
http://en.wikipedia.org/wiki/Breast_cancer_classification

  • Basal-like: ER-, PR- and HER2-; also called triple negative breast cancer (TNBC)[35] Most BRCA1 breast cancers are basal-like TNBC.
  • Luminal A: ER+ and low grade
  • Luminal B: ER+ but often high grade
  • Luminal ER-/AR+: (overlapping with apocrine and so called molecular apocrine) – recently identified androgen responsive subtype which may respond to antihormonal treatment with bicalutamide[31]
  • ERBB2/HER2+: has amplified HER2/neu[27]
  • Normal breast-like[11][33][36]
  • Claudin-low: a more recently described class; often triple-negative, but distinct in that there is low expression of cell-cell junction proteins[35] including E-cadherin[35] and frequently there is infiltration with lymphocytes.[33][37][38]
  • Useful links:
    1. National Cancer Institute – Breast cancer treatment
    2. Cancer Research UK – Treatment for Breast Cancer

     

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