BASIC SCIENCES OF BREAST CANCER

Dr D. RAMU

Epidemiology of breast cancer

• Most frequent cancer in women and second most frequent cause of cancer death

• For India, for the year 2012:

• 144,937 women were newly detected wth breast cancer

• 70,218 women died of breast cancer

• 144937 / 70218 = 2.06 = round it off to 2. So roughly, in India, for every 2 women newly diagnosed with breast cancer, one lady is dying of it.

Risk factors for breast cancer

• Reproductive• Age• Age at menarche• Age at first pregnancy (full term)• Parity• Breast feeding• Abortion• Age at menopause• Exogenous harmones

• Contraceptive harmones• Harmone replacement

• Genitic factors

• BRCA1/BRCA2

• P53/ Li fraumen syndrome

• PTEN/ Cowden syndrome

• Low penetrance genes

• Familial factors

• History of benign breast disease

• Lifestyle and dietery

• Alcohol and tobacco

• Physical activity

• Dietery

• Weight

• Radiation exposure

• Breast density

Magnitude of risk of known breast cancer risk factorsRelative risk <2 Relative risk 2 – 4 Relative risk >4

Early menarcheLate menopauseNulliparityEstrogen plus progesteroneHRTAlcohol usePostmenopausal obesity

One of the first degree relative with breast cancerCHEK2 mutationAge >35 y for first birthProliferative breast diseaseMammographic breast density

BRCA1 or BRCA2 mutationLCISAtypical hyperplasiaRadiation exposure before 30

Risk assessment models

• Gail risk assessment model

• Claus risk assessment model

• BRCAPRO assessment model

• Adjuvantonline

Management of the high risk patients

Risk reducing measure Relative risk (%)

Tamoxifen 37-49

Raloxifen 56-59

Exemestane 65

Bilateral prophylactic salpingo-oophorectomy

53

Bilateral prophylactic mastectomy 85-100

Natural history of disease

• Natural history and prognosis vey from patient to patient• Tumour doubling time from 44 days to 1800 with average of 212 days• Breast lump• Spontaneous nipple discharge

• 3% of women and 20% male breast cancer presentation

• Breast pain• Skin changes• Axillary lymphadenopathy• Nipple changes• Bone pains• Respiratory problems

• Halstadian theory

• Bernard fisher theory

• Third hypothesis

• Metastasis • Bone, liver lung, lymphnode,chestwall and brain

Screening of breast cancer

• Mammography• Reduces mortality rats of breast cancer by 24%• Annually• Start from 40 yrs• Life expectancy at least 3-5 yrs

• Breast physical examination• Lack of data showing reduced risk of death from breast cancer• Clinical breast examination

• Start from 20 yrs• At least every three years before 40 and annually after 40

• Breast self examination

• High risk patients

Diagnosis and biopsy

• Mammography

• MRI

• Ultrasonography

• Biopsy• Fine needle aspiration cytology• Core cutting needle biopsy• Excisional biopsy

• Staging work up• Chest X ray• Complete blood count and liver function test• Bone scan

Mammography

• Diffuse or scattered distribution is typically seen in benign entities.Even when clusters of calcifications are scattered throughout the breast, this favors a benign entity.

• Regional distribution according to the BI-RADS atlas would favor a non-ductal distribution (i.e. benignity), while

Segmental distribution would favor a ductal distribution (i.e. malignancy).Sometimes this differentiation can be made, but in many cases the differentiation between 'regional' and 'segmental' is problematic, because it is not clear on a mammogram or MRI where the bounderies of a segment (or a lobe) exactly are.

• Clustered calcifications are both seen in benign and malignant disease and are of intermediate concern.When clusters are scattered througout the breast, this favors a benign entity.A single cluster of calcification favors a malignant entity.

• Linear distribution is typically seen when DCIS fills the entire duct and its branches with calcifications.

MRI

American Cancer Society Guidelines for Magnetic Resonance Imaging Screening

ANNUAL MRI RECOMMENDED BASED ON EVIDENCEBRCA mutationUntested first degree relative of BRCA carrierLifetime risk of breast cancer 20% to 25%

ANNUAL MRI RECOMMENDED BASED ON EXPERT OPINIONRadiation to chest between age 10 and 30Li-Fraumeni syndrome and first-degree relativesCowden and Bannayan-Riley-Ruvalcaba syndromes and first-degree relatives

INSUFFICIENT EVIDENCE TO RECOMMEND FOR OR AGAINST MRILifetime breast cancer risk 15% to 20%Lobular carcinoma in situAtypical hyperplasia (lobular or ductal)Extremely or heterogeneously dense breasts on mammogramPersonal history of breast cancer, including DCIS

• For occult breast cancers

• Differentiate scar from recurrence

• Patient with breast implantsto

• Detect chest wall involvement

Biopsy

FNAC

• investigation of palpable masses, regardless of whether they are considered benign or malignant

• investigation of impalpable image-detected masses that are considered likely to be benign or with typically malignant features

• investigation of suspected local recurrence of breast cancer, as suggested by the presence of palpable masses, impalpable image-detected masses, or lymph node involvement

• evaluation of cystic lesions with atypical imaging features

• confirmation of a diagnosis of breast cancer when core biopsy is not available, not possible or contraindicated

• The relative advantages of FNA cytology, compared with core biopsy, include:

• the sampling procedure for FNA cytology is quicker to perform than core biopsy• in most instances FNA cytology does not require local anaesthetic• FNA cytology is generally less traumatic than core biopsy and may be more appropriate for women taking anticoagulant medication• FNA cytology is associated with a low complication rate• FNA cytology results are available relatively quickly (within a few hours in some centres); the presence of a cytopathologist may facilitate an immediate result• relatively inexpensive to perform.

• The relative disadvantages of FNA cytology, compared with core biopsy, include:

• FNA cytology requires training in the preparation of quality smears

• considerable cytology expertise is required to interpret FNA cytology

• FNA cytology is generally inappropriate for the assessment of microcalcifications

• FNA cytology does not enable the pathologist to distinguish between DCIS and invasive carcinoma

• Definitive diagnosis of some lesions can be difficult to make on the basis of FNA cytology.These include atypical ductal hyperplasia (ADH), lowgrade DCIS, some tubular carcinomas and some invasive lobular carcinomas

• FNA cytology may not be the sampling technique of choice for lesions that are relatively hypocellular and yield scanty epithelial material.These include sclerotic fibroadenomas, sclerosing ductal carcinoma, and infiltrating lobular carcinoma.

• Indications for core biopsy

• Core biopsy may be indicated in the following clinical situations:

• investigation of lesions with suspicious features identified on imaging that cannot be identified on ultrasound

• further evaluation of a benign cytological pattern in the presence of a suspicious lesion on imaging

• further evaluation of a lesion for which cytology results are atypical orsuspicious

• when a single surgical procedure is the desired outcome (for example wide excision and axillary dissection). It must be noted that a core biopsy showing only DCIS does not exclude the possibility of the presence of invasive carcinoma in the lesion

• evaluation of microcalcifications that are radiologically indeterminate, suspicious or typically malignant. In such cases core biopsies should be radiographed prior to histological processing to confirm adequate sampling of the lesion

• evaluation of suspicious architectural distortion at a site of previous malignancy

• evaluation of an area that has been treated with radiation.

• The relative advantages of core biopsy, compared with FNA cytology, include:• core biopsy is the investigation of choice in the evaluation of microcalcifications22

• core biopsy can be used when FNA cytology fails to correlate with clinical findings or imaging studies, as may occur with an inadequate cytology specimen (eg fewer than three to six epithelial groups per slide).23 If the cytological findings do not correlate with the clinical and/or imaging findings, further investigation should be performed

• core biopsy yields tissue fragments allowing architectural features of the lesion to be identified to determine whether DCIS or invasive carcinoma is present

• core biopsy is useful in the evaluation of lesions likely to be low histological grade and in those presenting as architectural distortions, for which FNA cytology may fail or has failed to provide a diagnosis

• core biopsy may be preferred when appropriate cytological expertise is not available

• compared with FNA cytology, core biopsy may achieve higher specificity and sensitivity. Limited data suggest it may increase the probability of obtaining a satisfactory and representative sample, particularly for imagedetected lesions

• tissue is usually available for adjunctive tests (ER, PR and Her2).

• Potential disadvantages of core biopsy include the following:• the reliability of core biopsy depends on the skill of the operator• false negatives may result from: (i) a ‘clear miss’, that is the lesion not being sampled, or (ii) artefactual distortion of the lesion and/or cores making definitive interpretation of the pathology changes on excision impossible

• it is not always possible to immediately assess the adequacy of core biopsyperformed for a mass lesion or architectural distortion. In the case of microcalcifications the specimen can be radiographed to confirm whether representative microcalcifications are present

• compared with FNA cytology, core biopsy is associated with an increased risk of complications, including haematoma,8 haemorrhage and needle tract implantation of tumour cells.2, 24, 25 These are more likely to occur if a large number of core biopsies are performed• core biopsy requires the use of a local anaesthetic• the mammographic lesion may not be identified in subsequent open biopsy, due to complete removal of the lesion or in the presence of inflammation and fibrosis due to biopsy• core biopsy may interfere with the interpretation of the subsequent excision biopsy, particularly with grading and the estimation of the size of the lesion.This is particularly relevant in the case of small lesions• core biopsy requires adequate fixation and processing, and generally requires a minimum of one working day before results can be availablefootnote• core biopsy is generally more expensive than FNA cytology.

• Indications for surgical biopsy after core needle biopsy

• Failure to sample calcification

• Diagnosis of atypical ductal hyperplasia

• Diagnosis of atypical lobular hyperplasia or lobular carcinoma insitu

• Lack of concordance between imaging findings and histologic diagnosis

• Radial scar

• Papillary lesion

Technique Advantages DisadvantagesFine needle aspiration cytology

Rapid, painless, inexpensive. No incision prior to selection of local therapy.

Does not distinguish invasive from in situ cancer. Markers (ER, PR, HER-2) not routinely available. Requires experienced cytopathologist. False negatives and insufficient specimens occur.

Core cutting needle biopsy

Rapid, relatively painless, inexpensive. No incision. Can be read by any pathologist, markers routinely available.

False-negative results, incomplete lesion characterization can occur.

Excisional biopsy False-negative results rare. Complete histology before treatment decisions. May serve as definitive lumpectomy.

Expensive, more painful. Creates an incision to be incorporated into definitive surgery. Unnecessary surgery with potential for cosmetic deformity in patients with benign abnormalities.

Staging • TX Primary tumor cannot be assessed

• T0 No evidence of primary tumor

• Tis Carcinoma in situ

• Tis (DCIS) Ductal carcinoma in situ

• Tis (LCIS) Lobular carcinoma in situ

• Tis (Paget’s) Paget’s disease of the nipple NOT associated with invasive carcinoma and/or carcinoma in situ (DCIS and/or LCIS) in the underlying breast parenchyma. Carcinomas in the breast parenchyma associated with Paget’s disease are categorized based on the size and characteristics of the parenchymal disease, although the presence of Paget’s disease should still be noted

• T1 Tumor ≤ 20 mm in greatest dimension

• T1mi Tumor ≤ 1 mm in greatest dimension

• T1a Tumor >1 mm but ≤ 5 mm in greatest dimension

• T1b Tumor >5 mm but ≤ 10 mm in greatest dimension

• T1c Tumor >10 mm but ≤ 20 mm in greatest dimension

• T2 Tumor >20 mm but ≤ 50 mm in greatest dimension

• T3 Tumor >50 mm in greatest dimension

• T4 Tumor of any size with direct extension to the chest wall and/or to the skin (ulceration

• or skin nodules).

• Note: Invasion of the dermis alone does not qualify as T4

• T4a Extension to the chest wall, not including only pectoralis muscle adherence/invasion

• T4b Ulceration and/or ipsilateral satellite nodules and/or edema (including peaud’orange) of the skin, which do not meetthe criteria for inflammatory carcinoma

• T4c Both T4a and T4b

• T4d Inflammatory carcinoma

• NX Regional lymph nodes cannot be assessed (e.g., previously removed)

• N0 No regional lymph node metastases

• N1 Metastases to movable ipsilateral level I, II axillary lymph node(s)

• N2 Metastases in ipsilateral level I, II axillary lymph nodes that are clinically fi xedor matted; or in clinically detected * ipsilateral internal mammary nodes in the absence of clinically evident axillary lymph node metastases

• N2a Metastases in ipsilateral level I, II axillary lymph nodes fi xed to one another (matted) or to other structures

• N2b Metastases only in clinically detected * ipsilateral internal mammary nodes and in the absence of clinically evident level I, II axillary lymph node metastases

• N3 Metastases in ipsilateral infraclavicular (level III axillary) lymph node(s) with or without level I, II axillary lymph node involvement; or in clinically detected * ipsilateral internal mammary lymph node(s) with clinically evident level I, II axillary lymph node metastases; or metastases in ipsilateral supraclavicular lymph node(s) with or without axillary or internal mammary lymph node involvement

• N3a Metastases in ipsilateral infraclavicular lymph node(s)• N3b Metastases in ipsilateral internal mammary lymph node(s) and axillary lymph

node(s)• N3c Metastases in ipsilateral supraclavicular lymph node(s)

• pN0(i−) No regional lymph node metastases histologically, negative IHC

• pN0(i+) Malignant cells in regional lymph node(s) no greater than 0.2 mm (detected by H&E or IHC including ITC)

• pN0(mol−) No regional lymph node metastases histologically, negative molecular findings (RT-PCR)

• pN0 (mol+) Positive molecular fi ndings (RT-PCR), ** but no regional lymph node metastases detected by histology or IHC

• pN1 Micrometastases; or metastases in 1–3 axillary lymph nodes; and/or in internal mammary nodes with metastases detected by sentinel lymph node biopsy but not clinically detected

• pN1mi Micrometastases (greater than 0.2 mm and/ or more than 200 cells, but none greater than 2.0 mm)

• pN1a Metastases in 1–3 axillary lymph nodes, at least

• one metastasis greater than 2.0 mm

• pN1b Metastases in internal mammary nodes with micrometastases or macrometastasesdetected by sentinel lymph node biopsy but not clinically detected ***

• pN1c Metastases in 1–3 axillary lymph nodes and in internal mammary lymph nodes with micrometastases or macrometastases detected by sentinel lymph node biopsy but not clinically detected

• pN2 Metastases in 4–9 axillary lymph nodes; orin clinically detected **** internal mammary lymph nodes in the absence of axillary lymph node metastases

• pN2a Metastases in 4–9 axillary lymph nodes (at least one tumor deposit greater than 2.0 mm)

• pN2b Metastases in clinically detected **** internal mammary lymph nodes in the absence of axillary lymph node metastases

• pN3 Metastases in ten or more axillary lymph nodes; or in infraclavicular (level III axillary) lymph nodes; or in clinically detected **** ipsilateral internal mammary lymph nodes in the presence of one or more positive level I, II axillary lymph nodes; or in more than three axillary lymph nodes and in internal mammary lymph nodes with micrometastasesor macrometastases detected by sentinel lymph node biopsy but not clinically detected *** ; or in ipsilateral supraclavicular lymph nodes

• pN3a Metastases in ten or more axillary lymph nodes (at least one tumor deposit greater than 2.0 mm); or metastases to the infraclavicular (level III axillary lymph) nodes

• pN3b Metastases in clinically detected **** ipsilateral internal mammary lymph nodes in the presenc of one or more positive axillary lymph nodes; or in more than three axillary lymph nodes and in internal mammary lymph nodes with micrometastases or macrometastases detected by sentinel lymph node biopsy but not clinically detected ***

• pN3c Metastases in ipsilateral supraclavicular lymph nodes

• Distant Metastases (M)

• M0 No clinical or radiographic evidence of distant metastases

• cM0(i+) No clinical or radiographic evidence of distant metastases, but deposits of molecularly or microscopically detected tumor cells in circulating blood, bone marrow, or other nonregional nodal tissue that are no larger than 0.2 mm in a patient without symptoms or signs of metastases

• M1 Distant detectable metastases as determined by classic clinical and radiographic means and/or histologically proven larger than 0.2 mm

• HISTOPATHOLOGIC TYPES

• In situ Carcinomas

• NOS (not otherwise specifi ed)

• Intraductal

• Paget’s disease and intraductal

• Invasive Carcinomas

• NOS

• Ductal

• Infl ammatory

• Medullary, NOS

• Medullary with lymphoid stroma

• Mucinous

• Papillary (predominantly micropapillary pattern)

• Tubular

• Lobular

• Paget’s disease and infi ltrating

• Undifferentiated

• Squamous cell

• Adenoid cystic

• Secretory

• Cribriform

Pathology of breast cancer

• Most of tumours arise from terminal duct lobular unit

• Infiltratinn ductal carcinoma not other specified• 75%

• Hrad on palpation

• Gritty on transection

• Associated with various degree of fibrosis

• Commnly metastasis to axilla

• Prognosis is poor

• Distance metastasis to bone , lung liver and brain

• Tumour with mixed histologic types behave as NOS type

• Infiltrating lobular carcinoma• 5-10%• Clinically ill defined thickening in breast• Microscopically single or indian file pattern• Multicentricity and bilaterality• Metastasis to unusual sites like meninges and serosal surface

• Tubular carcinoma• 2%• >75% tumour showing tubule formation• Nodal metastasis uncommon• Prognosis is good

• Medullary carcinoma• 5-7%

• Poorly differentiated nuclei , syncytial growth pattern

• Intense infiltration with mall lymphocytes and plasma cells

• Prognosis is favourable

• Mucinous or colloid carcinoma• 3%

• Abundant accumulation of mucine surrounding cluster of tumour cells

• Slow growing, tend to be bulky

• Prognosis favourable

Grading of breast carcinoma• Nottingham combined histologic grading (elston ellis modification of scarf bloom

Richardson grading system)

• Tubule formation

• Percent of the tumor forms normal duct structures• 1 point: tubular formation in more than 75% of the tumor• 2 points: tubular formation in 10 to 75% of the tumor• 3 points: tubular formation in less than 10% of the tumor

• Nuclear pleomorphism• 1 point: nuclei with minimal variation in size and shape• 2 points: nuclei with moderate variation in size and shape• 3 points: nuclei with marked variation in size and shape

• Mitotic count• 1 point: 0-9 mitotic counts per 10 fields under X25 objective • 2 points: 10-19 mitotic counts per 10 fields under X25 objective• 3 points: Over 19 mitotic counts per 10 fields under X25 objective

• Overall grade• 3-5 Grade 1 tumor (well-differentiated). Best prognosis• 6-7 Grade 2 tumor (moderately differentiated). Medium prognosis.• 8-9 Grade 3 tumor (poorly differentiated). Worst prognosis.

Molecular classification of breast carcinoma

• Luminal A• Express cytokeratin 8 and 18

• Highest level of ER expression, low expression of proliferative markers

• Low grade

• Respond to endocrine therapy

• Prognosis favourable

• Luminal B• Low epression of ER and ER related genes, high proliferation markers

• Prognosis poor

• Normal like breast cancer

• Geneexpression profile reminiscent of normal breast epithelium

• Prognosis similar to luminal B tumour

• HER2 amplified• Amplification of HER2 gene on 17q chromosome• IHC staining 3+(uniform intense membrane staining >30% of tumour cells)• FISH >6 gene copies per nucleus or FISH ratio (HER2 gene signal to chromosome 17

signal) >2.2• Decreased expression of ER&PR• Upregulation of vascular endothelial factor• Prognosis is poor

• Basal like• Triple negative ER&PR negative, HER2 negative• Cytokeratine 5,6 and 17positive• Prognosis poor

Genetics of breast cancer

• BRCA1 • 17q21• Breast cancer risk 60-85%• Breast, ovarian, prostate, colon, liver and bone cancer• Younger age, more aggressive, high grade, high proliferative rate, triple negative and

basal like . Mostly medullary histology

• BRCA2• 13q12.3• Breast cancer risk 60 to 85%• Male breast, ovary, pancrease, gall blader, pharynx, stomach, melanoma, fanconies

anemia• Histology similar to sporadic breast cancer

• TP53• 17p13.1

• Breast cancer risk 50 to89%

• Cowdens syndrome• PTEN-10q233.3

• 25-50% risk

BRCA testingFactors Suggestive of BRCA1 or BRCA2 Mutation

NON-ASHKENAZIC JEWISH WOMENTwo first-degree relatives with breast cancer, one diagnosed < 50 yearsThree or more first- or second-degree relatives with breast cancer, any ageBreast and ovarian cancer among first- and second-degree relativesFirst-degree relative with bilateral breast cancerBreast cancer in a male relativeTwo or more first- or second-degree relatives with ovarian cancer

ASHKENAZIC JEWISH WOMENFirst-degree relative with breast or ovarian cancerTwo second-degree relatives with breast or ovarian cancer

Prognostic and predictive factors• TNM classification

• Nodal involvement• Tumour size• Metastasis

• Inflamatory carcinoma

• Histological subtype

• Histological grade

• ER/PR status

• HER2/neu status

• LVI

• Proliferative index

• DNA content

• Response to neoadjuvent chemotherapy

• Gene expression profile

Prognostic indices of breast cancer

• Oncotype DX® 21-Gene Recurrence Score (RS) Assay

• Mamma printing

• Adjuvant online assay

Oncotype DX® 21-Gene Recurrence Score (RS) Assay

PROLIFERATION

Ki-67

STK15

Survivin

Cyclin B1

MYBL2

ESTROGEN

ER

PR

Bcl2

SCUBE2

INVASION

Stromelysin 3

Cathepsin L2

HER2

GRB7

HER2

BAG1GSTM1

REFERENCE

Beta-actin

GAPDH

RPLPO

GUS

TFRC

CD68

16 Cancer and 5 Reference Genes From 3 Studies

Category RS (0 -100)

Low risk RS <18

Int risk RS 18 - 30

High risk RS ≥ 31

Paik et al. N Engl J Med. 2004;351:2817-2826.

RS = + 0.47 x HER2 Group Score

- 0.34 x ER Group Score

+ 1.04 x Proliferation Group Score

+ 0.10 x Invasion Group Score

+ 0.05 x CD68

- 0.08 x GSTM1

- 0.07 x BAG1

• The Oncotype DX® Recurrence Score assay predicts the likelihood of adjuvant chemotherapy benefit

• It also is a prognostic assay for the risk of distant recurrence at ten years assuming five years of adjuvant tamoxifen treatment

• Oncotype DX® Recurrence Score assay shows consistent results across multiple independent studiesTrial Assigning IndividuaLized Options for Treatment (Rx) (TAILORx)

NSABP B20The Kaiser Permanente Study

• The MammaPrint test by Agendia analyzes 70 genes from an early-stage breast cancer tissue sample to figure out if the cancer has a low or high risk of coming back (recurrence) within 10 years after diagnosis.

• MammaPrint can only be used to analyze early-stage breast cancers. In the United States, MammaPrint can be used on cancers that are:

• stage I or stage II invasive

• smaller than 5 centimeters

• estrogen-receptor-positive or -negative

• Uses• A low-risk test result means that the cancer has a 10% risk of coming back

within 10 years without any additional treatments after surgery. With hormonal therapy alone this risk can be reduced to 5%.

• A high-risk test result means that the cancer has a 29% risk of coming back within 10 years without any additional treatments after surgery.

• Mammostrat Test• measures the levels of five genes in breast cancer cells. These genes can affect how

the breast cancer will behave and respond to certain treatments. These measurements are used to calculate a risk index score. The higher the risk index score, the more likely the cancer is to come back (recur).

• Women in the low risk category have a 7.6% risk of the cancer coming back within 10 years.

• Women in the moderate risk category have a 16.3% risk of the cancer coming back within 10 years.

• Women in the high risk category have a 20.9% risk of the cancer coming back within 10 years.

• Women in the high risk category are more likely to benefit from chemotherapy in addition to hormonal therapy after surgery. Women in the low risk category may be able to avoid chemotherapy that probably won’t give them any additional benefits.