Breast cancer classification

Breast Cancer Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Breast cancer from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

Diagnostic study of choice

History and Symptoms

Physical Examination

Laboratory Findings

Electrocardiogram

X-ray

CT scan

MRI

Echocardiography or Ultrasound

Other Imaging Studies

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Breast cancer classification On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Breast cancer classification

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Breast cancer classification

CDC on Breast cancer classification

Breast cancer classification in the news

Blogs on Breast cancer classification

Directions to Hospitals Treating Breast cancer

Risk calculators and risk factors for Breast cancer classification

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief:  Mirdula Sharma, MBBS [2] Soroush Seifirad, M.D.[3]

## Overview

[edit | edit source]

Breast cancer may be classified according to anatomy into 4 subtypes: ductal, lobular, sarcoma, and lymphoma. There are also other methods of classification such as classification based on gene expression, and classification based on hormone receptors present. In practice, a combination of all above mentioned classification is combined with the surgical characteristics of tumors and radiologic findings is being applied for patient management, treatment planning, and prognosis determination.

## Classification based on histopathology

[edit | edit source]

### Malignant Tumors

[edit | edit source]

Type | Subtype

Ductal

* Ductal carcinoma in situ (DCIS)[1]

* Comedo type: ~60%
* Non-comedo type: ~40%

* Papillary
* Micropapillary
* Cribriform
* Solid

* Intracystic papillary carcinoma in situ

* Invasive ductal carcinoma

* Invasive ductal carcinoma not otherwise specified (NOS): ~65%
* Tubularcarcinoma of breast: ~7-8%

* Tubulolobular carcinomaof breast

* Medullarycarcinoma of breast: ~2%
* Mucinous (colloid) carcinoma: ~2%
* Malignant papillary lesions of the breast

* Papillary carcinoma of breast: 1-2% 1

Lobular

* Lobular carcinoma in situ (LCIS)
* Invasive lobular carcinoma: ~10%

Other malignant breast tumors

* Inflammatory breast cancer: 1-4%
* Paget's disease of the breast
* Triple negative and basal-like breast cancers
* Metaplastic carcinoma of the breast
* Adenoid cystic carcinoma of the breast: <0.4%
* Apocrine carcinoma of the breast

Sarcoma

* Angiosarcoma of the breast
* Fibrosarcoma of breast
* Extra-skeletal osteosarcoma of breast
* Malignant phyllodes tumor
* Angiosarcoma
* Rhabdomyosarcoma

Lymphoma

* Non-hodgkin lymphoma

Metastases to the breast

The most common extra-mammary cancers that metastasise to breast are:

* Lymphoma/leukaemia: most common extra mammary source
* Melanoma
* Sarcomas
* Prostate cancer: considered on the most frequent primary sites in men 4
* Lung cancer
* Gastric cancer
* Ovarian cancer
* Renal cell cancer

### Benign Tumors

[edit | edit source]

* Phyllodes tumor[1]
* Mammary fibromatosis: 0.2% of all breast tumors 5
* Benign papillary lesions of the breast

* Papilloma

* Intraductal papilloma
* Solitary papilloma of breast
* Central solitary papilloma of breast
* Peripheral solitary papilloma of breast
* Multiple papillomata of breast

* Juvenile papillomatosis of breast

* Granular cell tumor of the breast

## Classification based on hormone receptors present

[edit | edit source]

* Hormone receptor positive: either estrogen or progesterone receptors are present
* Hormone receptor negative: breast cancer cells do not have either estrogen or progesterone receptors
* HER2 positive: If excess copies of HER2 gene
* HER2 negative: If excess copies of HER2 gene are not present
* Triple positive: cancers that are ER-positive, PR-positive, and have too much HER2
* Triple negative: If the breast cancer cells don not have estrogen or progesterone receptors and don’t have too much HER2

## Classification based on gene expression

[edit | edit source]

* Luminal type: are estrogen receptor (ER)–positive

* Luminal A:

* Expression of luminal (low molecular weight) cytokeratins, high expression of hormone receptors and related genes
* 50% of invasive bresat cancer, ER/PR positive, HER2/neu negative
* Tubular carcinoma, Cribriform carcinoma, Low grade invasive ductal carcinoma, NOS, Classic lobularcarcinoma
* Response to endocrine therapy
* Variable response to chemotherapy
* Low grade,
* Grows slowly,
* Good prognosis (the best prognosis)

* Luminal B :

* Expression of luminal (low molecular weight) cytokeratins, moderate-low expression of hormone receptors and related genes
* 20% of invasive breast cancer, ER/PR positive, HER2/neu expression variable, higher proliferation than Luminal A, higher histologic grade than Luminal A
* Invasive ductal carcinoma, NOS Micropapillary carcinoma
* Response to endocrine therapy (tamoxifene and aromatase inhibitors) not as good as Luminal A
* Variable response to chemotherapy (better than Luminal A)
* Prognosis not as good as Luminal A
* Grows faster

* HER2/neu

* High expression of HER2/neu, low expression of ER and related genes
* 15% of invasive breast cancer, ER/PR negative, HER2/neu positive, high proliferation, diffuse TP53 mutation, high histologic grade and nodal positivity
* High grade invasive ductal carcinoma, NOS
* Response to trastuzumab (Herceptin)
* Response to chemotherapy with antracyclins
* Usually unfavorable prognosis

* Basal like

* High expression of basal epithelial genes and basal cytokeratins, low expression of ER and related genes, low expression of HER2/neu
* ~15% of invasive breast cancer, most ER/PR, HER2/neu negative (triple negative), high proliferation, diffuse TP53 mutation, BRCA1 dysfunction (germline, sporadi
* High grade invasive ductal carcinoma, NOS Metaplastic carcinoma, Medullary carcinoma
* No response to endocrine therapy or trastuzumab
* Sensitive to platinum group chemotherapy and PARP inhibitors
* Not all, but usually worse prognosis[2]

## References

[edit | edit source]

1. ↑ 1.0 1.1 Breast Neoplasm. Radiopedia. (2015) http://radiopaedia.org/articles/breast-neoplasms Accessed on March 1, 2019
2. ↑ Eliyatkın N, Yalçın E, Zengel B, Aktaş S, Vardar E (2015) Molecular Classification of Breast Carcinoma: From Traditional, Old-Fashioned Way to A New Age, and A New Way. J Breast Health 11 (2):59-66. DOI:10.5152/tjbh.2015.1669 PMID: 28331693

Template:WikiDoc Sources