TBL 1.1 Flashcards
What is the most common non-skin malignancy in women?
Breast cancer
What is the second most common cause of cancer deaths in the United States?
Breast cancer
What are the most important risk factors for sporadic breast cancers in women?
Estrogenic stimulation and age
What percentage of breast cancers are familial?
Approximately a quarter to a third
Which high-risk genes are associated with familial breast cancer?
BRCA1, BRCA2, and TP53
How are breast cancers classified into molecular groups?
Into luminal (ER-positive), HER2, and triple negative groups
What distinguishes luminal cancers group A from group B?
Group A has low proliferation, while group B has high proliferation
What characterizes HER2 cancers?
Overexpression of the HER2 receptor due to HER2 gene amplification
What is a defining feature of triple negative breast cancers (TNBCs)?
They lack ER and HER2 expression
What is the prognosis for TNBCs?
They carry a relatively poor prognosis
What type of carcinoma do almost all breast malignancies represent?
Adenocarcinomas
What are the terms used to describe subsets of breast carcinomas?
Ductal and lobular
From where do most breast carcinomas arise?
From cells in the terminal duct lobular unit
How was carcinoma in situ originally classified?
As ductal carcinoma in situ (DCIS) or lobular carcinoma in situ (LCIS) based on the resemblance of involved spaces to normal ducts or lobules.
What does the term “lobular” refer to in current convention?
Invasive carcinomas that are biologically related to LCIS
What does carcinoma in situ refer to?
Cancer cells confined within ducts and lobules by a basement membrane
Why does carcinoma in situ have no capacity to metastasize?
Because the location precludes access to blood vessels and lymphatics
What is ductal carcinoma in situ (DCIS)?
A clonal proliferation of epithelial cells limited to ducts and lobules
How is DCIS typically detected?
Almost always by mammography
What percentage of carcinomas detected without mammography are in situ lesions?
Less than 5%
What percentage of carcinomas detected in mammography screened populations are in situ lesions?
15% to 30%
What are common findings associated with DCIS on mammography?
Calcifications associated with secretory material or necrosis
What is a rare presentation of DCIS?
Nipple discharge
What defines comedo DCIS?
Pleomorphic, high-grade nuclei and areas of central necrosis
How does the architectural patterns of DCIS vary?
They vary in nuclear grade and the presence and extent of necrosis
What does micropapillary DCIS produce?
Complex bulbous protrusions without fibrovascular cores
What characterizes cribriform DCIS?
Rounded spaces filled with calcified secretory material
What is Paget disease of the nipple?
A rare [1% to 4% of cases] manifestation of breast cancer presenting as a unilateral erythematous eruption
What does papillary DCIS produce?
True papillae with fibrovascular cores that lack a myoepithelial cell layer
How do malignant cells in Paget disease extend from DCIS?
Within the ductal membrane via the lactiferous sinuses into nipple skin without crossing the basement membrane.
What are common symptoms of Paget disease of the nipple?
Pruritus and a scale crust
What is the significance of a palpable mass in women with Paget disease?
50% to 60% of women with Paget disease have a palpable mass, which is usually invasive carcinoma
What are the key features of ductal carcinoma in situ (DCIS)?
- Clonal proliferation of epithelial cells limited to ducts and lobules
- Myoepithelial cells are preserved, though may be diminished
- Can spread throughout the ductal system
- Detected almost always by mammography
- Associated with calcifications or necrosis
What is the prognosis for women with Paget disease?
Prognosis depends on the features of the underlying carcinoma and is not affected by the presence or absence of paget disease.