Principles and Practice II
Chapter 34 Notes:
Breast cancer is the most common noncutaneous malignancy in the U.S and the second most
common cause of cancer death
1/8 women develop breast cancer by age 70 (risk increases with age)
Outcomes are more favorable for older patients since malignancy is slow-growing and indolent
in nature
BMI of 33 or higher have a 1.3 times higher chance of developing breast cancer than a BMI of
21 or lower
Nulliparous – never had a child
Risk rises with:
- Prolonged estrogen exposure
- Nulliparous
- Women whose first pregnancy is later in life
- Prolonged use of hormone replacement therapy
- Early menarche (period)
- Late menopause
- Proliferative benign breast lesions
o Atypical ductal hyperplasia (ADH) and atypical lobular hyperplasia (ALH) are
abnormal noninvasive proliferations
o Most proliferative benign breast lesions have cellular features of ductal carcinoma
in situ (DCIS) or lobular carcinoma in situ (LCIS)
- Breast density (glandular to adipose) (dense breasts are 4-5 times more likely to develop
breast cancer)
- Contralateral noninvasive (DCIS) or invasive breast cancer
- Family history
- 5%-6% of breast cancers are attributable to breast cancer susceptibility gene mutations in
BRCA1 or BRCA2
o BRCA1 = 60%
o BRCA2 = 55%
- Tobacco use
- Night shift work (nocturnal light exposure, suppression of melatonin by the pineal gland)
- Radiation exposure at a young age (radiation before age 20 means a 34% predictive risk)
The adult breast is located between the 2nd-6th ribs in the sagittal plane
- Extends from the sternochondral junctions to the midaxillary line in the axial plane
- Breast tissue is also located in the axilla and extending along the inferolateral edge of the
pectoralis major and forming the axillary tail of Spence
, The breast parenchyma consists of 15-20 lobes (there are numerous lobules in each lobe) that are
embedded in adipose tissue
- Each lobe is drained by a lactiferous duct that opens at the nipple
- Ductal carcinoma is the type that originates from a lactiferous duct
- Lobular carcinoma is the type that originates in the lobules of the breast
The nipple is a conical prominence in the center of the areola that is mostly composed of smooth
muscle fibers that compress the lactiferous ducts
The venous drainage of the breast is mainly to the axillary vein through the lateral thoracic and
lateral mammary veins
Intramammary lymph nodes are located within the breast parenchyma
- Can be associated with mets
- Part of nodal staging
Primary deep lymphatic drainage of the breast occurs to the ipsilateral axilla
- Between 10-50 lymph nodes are scattered throughout each axilla
The internal mammary lymph nodes are located in the parasternal space
- Most of these nodal recurrences are seen in the 1st, 2nd, or 3rd intercostal space
- Innerquadrant tumors have higher chance of internal mammary involvement (30%)
Supraclavicular lymph nodes are located in the supraclavicular fossa
- These nodes provide drainage for internal mammary and axilla nodes
- Very small amount of tumors drains to the supraclavicular nodes directly
Most frequent presentation is an asymptomatic, nonpalpable mass
Mammography, biopsy confirms pathology
Most common physical sign is a painless mobile mass
Advanced disease indicators:
- Enlarged or matted nodes
- Nipple discharge
- Palpable mass
- Skin involvement
Inflammatory breast cancer (IBC) is an aggressive form of breast cancer that presents with a
rapid onset, skin erythema, and asymmetric enlargement (not associated with a palpable mass)
Mammography, ultrasound, and MRI are the most established screening modalities
An annual mammography is the mainstay of breast cancer screening
- Includes two views of each breast: craniocaudal (CC) and mediolateral oblique (MLO)
- Mammography can miss 10%-15% of tumors, particularly lobular carcinomas
- Breast tomosynthesis (3D mammography)
Ultrasound is not appropriate as a single screening modality because it is unable to detect
calcifications and isn’t sensitive enough to detect small lesions
Chapter 34 Notes:
Breast cancer is the most common noncutaneous malignancy in the U.S and the second most
common cause of cancer death
1/8 women develop breast cancer by age 70 (risk increases with age)
Outcomes are more favorable for older patients since malignancy is slow-growing and indolent
in nature
BMI of 33 or higher have a 1.3 times higher chance of developing breast cancer than a BMI of
21 or lower
Nulliparous – never had a child
Risk rises with:
- Prolonged estrogen exposure
- Nulliparous
- Women whose first pregnancy is later in life
- Prolonged use of hormone replacement therapy
- Early menarche (period)
- Late menopause
- Proliferative benign breast lesions
o Atypical ductal hyperplasia (ADH) and atypical lobular hyperplasia (ALH) are
abnormal noninvasive proliferations
o Most proliferative benign breast lesions have cellular features of ductal carcinoma
in situ (DCIS) or lobular carcinoma in situ (LCIS)
- Breast density (glandular to adipose) (dense breasts are 4-5 times more likely to develop
breast cancer)
- Contralateral noninvasive (DCIS) or invasive breast cancer
- Family history
- 5%-6% of breast cancers are attributable to breast cancer susceptibility gene mutations in
BRCA1 or BRCA2
o BRCA1 = 60%
o BRCA2 = 55%
- Tobacco use
- Night shift work (nocturnal light exposure, suppression of melatonin by the pineal gland)
- Radiation exposure at a young age (radiation before age 20 means a 34% predictive risk)
The adult breast is located between the 2nd-6th ribs in the sagittal plane
- Extends from the sternochondral junctions to the midaxillary line in the axial plane
- Breast tissue is also located in the axilla and extending along the inferolateral edge of the
pectoralis major and forming the axillary tail of Spence
, The breast parenchyma consists of 15-20 lobes (there are numerous lobules in each lobe) that are
embedded in adipose tissue
- Each lobe is drained by a lactiferous duct that opens at the nipple
- Ductal carcinoma is the type that originates from a lactiferous duct
- Lobular carcinoma is the type that originates in the lobules of the breast
The nipple is a conical prominence in the center of the areola that is mostly composed of smooth
muscle fibers that compress the lactiferous ducts
The venous drainage of the breast is mainly to the axillary vein through the lateral thoracic and
lateral mammary veins
Intramammary lymph nodes are located within the breast parenchyma
- Can be associated with mets
- Part of nodal staging
Primary deep lymphatic drainage of the breast occurs to the ipsilateral axilla
- Between 10-50 lymph nodes are scattered throughout each axilla
The internal mammary lymph nodes are located in the parasternal space
- Most of these nodal recurrences are seen in the 1st, 2nd, or 3rd intercostal space
- Innerquadrant tumors have higher chance of internal mammary involvement (30%)
Supraclavicular lymph nodes are located in the supraclavicular fossa
- These nodes provide drainage for internal mammary and axilla nodes
- Very small amount of tumors drains to the supraclavicular nodes directly
Most frequent presentation is an asymptomatic, nonpalpable mass
Mammography, biopsy confirms pathology
Most common physical sign is a painless mobile mass
Advanced disease indicators:
- Enlarged or matted nodes
- Nipple discharge
- Palpable mass
- Skin involvement
Inflammatory breast cancer (IBC) is an aggressive form of breast cancer that presents with a
rapid onset, skin erythema, and asymmetric enlargement (not associated with a palpable mass)
Mammography, ultrasound, and MRI are the most established screening modalities
An annual mammography is the mainstay of breast cancer screening
- Includes two views of each breast: craniocaudal (CC) and mediolateral oblique (MLO)
- Mammography can miss 10%-15% of tumors, particularly lobular carcinomas
- Breast tomosynthesis (3D mammography)
Ultrasound is not appropriate as a single screening modality because it is unable to detect
calcifications and isn’t sensitive enough to detect small lesions
