Molecular Classification of Breast Cancer Dr. S. Rajendiran Prof. of Pathology Sri Ramachandra University, Chennai, India
Nov 28, 2014
Molecular Classification of Breast Cancer
Dr. S. RajendiranProf. of Pathology
Sri Ramachandra University, Chennai, India
Game Plan Pre-Test
Post-Test
Molecular Molecular Classification Classification of Ca Breastof Ca Breast
WhyWhyHowHow
UtilityUtility
PrognosticatioPrognosticationn
Pit Pit fallsfalls
ReferencesReferences
TakeTakeHome Home
MessageMessage
Pre Test 1•What is the problem in the current
classification of breast cancer?
a. Subjectiveb. Not accuratec. Over treatment of low risk diseases & under treatment of high risk diseasesd. All of the above
Pre Test 2•Which tumor is associated with
good prognosis?
a. Luminal typeb. Her 2 typec. Normal typed. Basal type
Pre Test 3•Herceptin is very useful in the
following type of breast cancer
a. Luminal typeb. Her 2 typec. Normal typed. Basal type
Pre Test 4•Which molecular type of breast cancer
is associated with BRCA 1 mutation?
a. Luminal typeb. Her 2 typec. Normal typed. Basal type
Pre Test 5
•How will you differentiate luminal A and B subtypes?
a. ER positivityb. PR positivityc. Her2 amplification in some tumorsd. ER, PR and Her 2 negative
WHO 2003 classification of Tumors of the Breast
1. Epithelial tumours 1.1 IDC 1.2 ILC 1.3 Tubular 1.4 Invasive cribriform 1.5 Medullary 1.6 Mucinous ca and other tumours with abundant mucin 1.6.1 Mucinous ca 1.6.2 Cystadenocarcinoma and col cell mucinous ca 1.6.3 Signet ring cell ca 1.7 Neuroendocrine tuomurs 1.7.1 Solid neuroendocrine ca 1.7.2 Atypical carcionid tumour 1.7.3 Small cell / oat cell ca 1.7.4 Large cell neuroendocrine ca 1.8 Invasive papillary ca 1.9 Invasive micropapillary ca 1.10 Apocrine ca 1.11 Metaplastic carcinomas 1.11.1 Pure epithelial metaplastic ca 1.11.1.1 Squamous cell ca 1.11.1.2 Adenoca with spin- dle cell metaplasia 1.11.1.3 Adenosquamous ca 1.11.1.4 Mucoepidermoid ca 1.11.2 Mixed epithlial/ mesen- chymal metaplastic ca 1.12 Lipid-rich ca 1.13 Secretory ca 1.14 Oncocytic ca 1.15 Adenoid cystic ca 1.16 Acinic cell ca 1.17 Glycogen-rich clear cell ca 1.18 Sebaceous ca 1.19 Inflammatory ca1.20 Lobular neoplasia 1.20.1 Lobular ca in situ 1.21 Intraductal proliferative lesions 1.21.1 Usual ductal hyperplasia
1.21.2 Flat epithelial atypia 1.21.3 Atypical ductal hyper- plasia 1.21.4 Ductal carcinoma in situ1.22 Microinvasive ca 1.23 Intraductal papillary neoplasms 1.23.1 Central papilloma 1.23.2 Peripheral papilloma 1.23.3 Atypical papilloma 1.23.4 Intraductal papillary car- cinoma 1.23.5 Intracystic papillary ca 1.24 Benign epithelial proliferations 1.24.1 Adenosis including vari- ants 1.24.1.1 Sclerosing adenosis 1.24.1.2 Apocrine adenosis 1.24.1.3 Blunt duct adenosis 1.24.1.4 Microglandular adenosis 1.24.1.5 Adenomyoepithelial adenosis 1.24.2 Radial scar / complex sclerosing lesion 1.25 Adenomas 1.25.1 Tubular adenoma 1.25.2 Lactating adenoma 1.25.3 Apocrine adenoma 1.25.4 Pleomorphic adenoma 1.25.5 Ductal adenoma2. Myoepithelial lesions 2.1 Myoepitheliosis 2.2 Adenomyoeithelial adenosis 2.3 Adenomyoepithelioma 2.4 Malignant myoepithelioma3. Mesenchymal lesions 3.1 Haemangioma 3.2 Angiomatosis 3.3 Haemangiopericytoma 3.4 Pseudoangiomatous stromal hyperplasia 3.5 Myofibroblastoma
3.6 Fibromatosis (aggressive) 3.7 Inflammatory myofibroblastic tumour 3.8 Lipoma 3.8.1 Angiolipoma 3.9 Granular cell tumour 3.10 Neurofibroma 3.11 Schwannoma 3.12 Angiosarcoma 3.13 Liposarcoma 3.14 Rhabdomyosarcoma 3.15 Osteosarcoma 3.16 Leiomyoma 3.17 Leiomyosarcoma 4. Fibroepithelial tumours 4.1 Fibroadenoma 4.2 Phyllodes tumour 4.2.1 Benign 4.2.2 Broderline 4.2.3 Malignant 4.3 Periductal stromal sarcoma, low grade 4.4 Mammary hamartoma5. Tumours of the nipple 5.1 Nipple adenoma 5.2 Syringomatous adenoma 5.3 Paget disease of the nipple 6. Malignant lymphoma 6.1 Diffuse large B-cell lymphoma 6.2 Burkitt lymphoma 6.3 Extranodal marginal-zone B-cell lymphoma of MALT type 6.4 Follicular lymphoma 7. Metastatic tumours 8. Tumours of the male breast 8.1 Gynecomastia 8.2 Carcinoma 8.2.1 Invasive 8.2.2 In situ
Why Classification?
•To memorize during the training ?
•To reproduce in the exam ?
•To confuse students, physicians and patients?
Why Classification ?
•To help the learner (improve the understanding)
•To help the physician (inform the prognosis, selection of treatment)
•To help the patient (disease free survival, quality of life)
Current Situation
•Morphological classification
•Histological grade (Nottingham score)
•IHC (ER, PR, her2-neu)
•TNM Stage (clinical & pathological)
Current Problem
•Highly subjective
•Not accurate
•Three tier system (low, intermediate and high grade/risk)
•Over treatment of low risk diseases & under treatment of high risk diseases
Histological grade and Histological grade and survivalsurvival
Pre-Pre-systemic systemic therapytherapy
Post-Post-systemic systemic therapytherapy
Current ProblemSimilar features ........ different outcome
Looking for Looking for
Similar features .......... similar outcome
Molecular Classification
How ?
Perou et al 2000
•40 cases
•8102 microarray
•1753 genes
•496 intrinsic genes
•Subtyping by hierarchial clustering
CK 5,6,14,15,17
High ERNo Her2Low p53,
Ki67
CK 7,8,18,19
ER -ER -PR -PR -
Her2 -Her2 -EGFR, p53, Ki67EGFR, p53, Ki67
ckitckit
Her 2 +++ ER -PR -AR+
High p53, Ki67
Gene profile similar to
normal breast control
Luminal ALuminal A
Luminal BLuminal B
BasalBasal
NormalNormal
Her 2Her 2
Low ERHigher Her2
High p53, Ki67
Molecular Classification
•5 types
•Normal breast like cancers
•Luminal A breast cancers
•Luminal B breast cancers
•Her 2 positive cancers
•Basal like carcinomas
Normal breast like cancers
•Gene expression similar to normal control
•Consistently clustered together with fibroadenoma and normal breast tissue
Result of analyzing admixed “normal” or benign breast tissue
Disappeared
Disappeared
Luminal A breast cancer
•Luminal cytokeratin
•High ER, PR
•Her 2 negative, low proliferation index
•Low histological grade
•Excellent prognosis
•Hormone therapy (Tamoxifen, SERMs & aromatase inhibitors)
•No benefit from chemotherapy
Luminal B breast cancer
•Luminal cytokeratin
•Low ER, PR
•Her 2 +, High proliferation index
•High histological grade
•Poor prognosis
•Hormone therapy (Tamoxifen, SERMs & aromatase inhibitors)
•Some response to chemotherapy
Her2 positive cancer
•No ER, PR
•Her 2 +++, High proliferation index
•High histological grade, node positive
•Poor prognosis
•Response to Herceptin
•Anthracyclin based chemotherapy
Basal Phenotype
•ER, PR & her2neu: Negative
•CK 5/6: Positive
•EGFR: Positive
•p63, p53 and c-kit: Positive
Histology of basal type carcinoma
•Nottingham grade 3
•Syncytial growth with pushing borders
•Geographic necrosis
•Stromal lymphocytes
•Mostly triple negative (ER, PR & her2neu)
•CK 5/6 positive High ki67 index
Similar to Atypical medullary carcinoma
Sensitivity to chemotherapy
•Luminal A/B: 2/30
•Normal breast like: 0/10
•her2neu: 9/20
•Basal like: 10/22 (P value: <0.001)
Heterogenity in basal like sub type
•Histological: Ductal, medullary, adenoid cystic, metaplastic
•CK expression: Variable
•All are not triple negativeTTNN
Basal likeBasal like
Basal like carcinoma
•BRCA 1 mutation (Brain & Lung mets)
•Defect in DNA repair pathway
•Target for new therapies
•PRAP inhibitors
•Platinum based chemo
Basal Type CarcinomaSummary•5-10% of cases
•Poor prognosis
•Good sensitivity to chemotherapy
•BRCA 1 dysregulation
•Most - triple negative by IHC
•Search for better therapies...????
Basal like and TN...?
•Currently no difference in therapy
•Treated as TN
•BRCA 1 screening
Strong association but not interchangeable
IHC vs mRNA profile
Pathology
Luminal A
Luminal B
Her 2 Basal
ER + 96% 20% 46% 12%
Her2 + 12% 20% 100% 10%
Grade 3 19% 53% 74% 84%
ER+, ER+, her2-, LGher2-, LG
ER+, ER+, her2+/-, her2+/-,
LGLG
ER-, ER-, her2+, her2+,
HGHG
ER-, ER-, her2-, HGher2-, HG
Summary
•All breast carcinoma are not alike
•Subtypes associated with outcome
•Subtypes have overlap
ER +ER + BasaBasal CK l CK ++
her2 her2 ++
70-75%70-75% 10-15%10-15% 15-20%15-20% 5-10%5-10%
FortuneTellers
•What is the prognosis?
•Who will respond to particular therapy?
•What will be the treatment for a particular tumor in a person? (Individual cancer treatment)
Traditional factors
•Tumor type
•Nottingham grade
•Margin status
•Lymphnode involvement
•Metastasis
Treatment options
•Surgery
•Radiation
•Hormone therapy
•Chemotherapy
• Tumor type
• Nottingham grade
• Margin status
• Lymphnode involvement
• Metastasis
To give To give oror
Not to giveNot to give
Who should get Chemotherapy?
•Calculators
•Risk stratifiers
1. Adjuvant online1. Adjuvant online2. St. Gallen Criteria2. St. Gallen Criteria3. Gene expression 3. Gene expression signaturesignature
Gene Expression Signature
mRNA
Microarray
RTPCR
1. Top down approach
Subclassify by clinical outcome
what is the pattern in good prognosis group?
2. Bottom up approachSubclssify by biological
hypothesisWhat is the pattern in metastatic tumors?
3. Candidate geneWhat is the effect of a particular
gene?What is the outcome of all the tumors with
p53 mutation?
Commercially available genomic
assays•MammaPrint
•Oncotype Dx
•Theros
•MapQuant Dx
Variable MammaPrint Oncotype Dx Theros MapQuant DX
Type of assay 70 gene assay21 gene
recurrence score
2 gene ratio of H/I and
molecular grade index
Genomic grade
Sample Fresh/frozen FFPE FFPE Fresh/frozen
TechniqueDNA
microarraysQ-RT-PCR Q-RT-PCR
DNA microarrays
Level of evidence
1- strongestV - Weakest
111 11 111 111
FDA FDA approvedapproved
United States United States EuropeEurope
USUS EuropEuropee
MINDACTMINDACT TAILORxTAILORx
Pit falls of Gene Expression
Profiling•Fresh/Frozen tissue - Sampling error
•Not reproducible 100%
•Still overlap exists (but definitely less)
•Host response not considered (Comorbid, drug metabolism, immune status)
•Cost
Post Test 1•What is the problem in the current
classification of breast cancer?
a. Subjectiveb. Not accuratec. Overtreatment of low risk diseases & undertreatment of high risk diseasesd. All of the above
dddd
Post Test 2•Which tumor is associated with
good prognosis?
a. Luminal typeb. Her 2 typec. Normal typed. Basal type
aaaa
Post Test 3•Herceptin is very useful in the
following type of breast cancer
a. Luminal typeb. Her 2 typec. Normal typed. Basal type
bbbb
Post Test 4•Which molecular type of breast cancer
is associated with BRCA 1 mutation?
a. Luminal typeb. Her 2 typec. Normal typed. Basal type
dddd
Post Test 5
•How will you differentiate luminal A and B subtypes?
a. ER positivityb. PR positivityc. Her2 amplification in some tumorsd. ER, PR and Her 2 negative
cccc
Take home message
•Biological rather than morphological
•Selection of patients for chemotherapy (ER+, LN -)
•Individualized treatment - Tailor made (not ready made...!!!!)
70-75%70-75% 10-15%10-15% 15-20%15-20% 5-10%5-10%
Reference
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