Breast Carcinoma Flashcards
What is breast cancer?
Breast cancer arises from epithelial cells of the milk ducts and lobules. The most common type is infiltrating ductal carcinoma.
How common is breast cancer?
Breast cancer is the most common cancer in women who don’t smoke
What are the non-invasive breast cancer histology?
Ductal cancer in situ
Lobular cancer in situ
What are the invasive breast cancer histology?
Infiltrating ductal cancer
Infiltrating lobular cancer
Metaplastic cancer
Mucinous cancer
Medullary cancer
Papillary cancer
Tubular cancer
What role does oestrogen play in breast cancer?
Physiology:
=> At menarche, oestrogen receptors in breast tissue react to ovarian oestrogen secretion.
=> This stimulation causes milk duct epithelial cells to divide allowing breast to develop physiologically.
Pathology:
=> Dysregulation of the above pathway = key in the progression of oestrogen receptor (ER) +ve breast cancer
=> Long term exposure to the mitotic effects of oestrogen = predisposing factor to breast tissue because mutations more likely to occur during replication
=> Early menarche or late menopause ; hormone replacement therapy = risk factor for breast cancer
What is the genetic predisposition to breast cancer?
5% of breast cancer patients have a genetic predisposition.
=> Familial BRCA mutant carriers - high risk of breast and ovarian cancer
=> Men +ve for BRCA - high risk of male breast cancer ; BRCA2 mutation - prostate cancer
=> Young breast cancer patients, strong family hx, male breast cancer need genetic counselling
What is the breast screening programme?
Bi-planar digital Mammography every 3 years in all women aged 50-70 years => allows early detection of breast cancers
Any abnormal mammograms recalled for further assessment
Mammograms aim to pick up pre-cancerous changes when it is still highly curable
Pre-cancerous changes:
=> In situ breast cancers = development of cancerous changes in the milk duct epithelium cells
=> hasn’t breached the basement membrane of the ducts
=> no access to spread by lymphatics
What are the clinical features of symptomatic breast cancer?
Painless, increasing mass
Nipple discharge
Skin tethering
Ulceration
In inflammatory cancers = oedema, erythema
What features are important to document during breast examination?
=> Position of the lesion in the breast
=> Size in centimetres
=> Presence or absence of tethering (superficial or deep)
=> Nipple discharge
=> Skin oedema aka peau d’orange appearance
=> Inflammatory changes
=> Presence or absence of axillary lymphadenopathy
Investigations:
What is the triple assessment of a symptomatic breast mass?
- Palpation
- Radiology
=> ultrasound <35yrs ; mammography >35yrs - Fine needle aspiration cytology or core needle biopsy
The triple assessment is effective in differentiating breast cancer from benign breast masses.
=> Benign masses 15x more common
Investigations:
What other investigations are carried out in breast cancer?
If breast cancer is likely, large-bore core needle biopsy is needed to confirm histology assess features for prognosis & response to treatment.
These features include:
=> Grade of tumour
=> Ki-67 proliferation index (Ki-67 protein = marker of cell proliferation)
=> Oestrogen, progesterone, HER-2 receptor status
=> Molecular profiling
For staging:
=> Tumour size & evidence of local invasion
=> Axillary lymph node status - scanning the sentinal nodes of the breast area, identified by dye or radioactive tracer
=> Examine common sites of metastases in advanced disease via PET-CT scan
What is the surgical management for breast cancer?
Early disease:
=> Wide local excision
=> segmental mastectomy
=> with breast conservation for masses of <3cm
Larger tumours:
=> Simple mastectomy
=> ± breast reconstruction
=> Axillary node sampling/ surgical clearance or sentinel node biopsy
Choice dependent on location and extent of breast mass + patient preference
*Clear histological margin around cancer = important for cure
No surgery to axilla if sentinal node biopsy -ve
If +ve, dissection of nodes required
*Greater the amount of axillary surgery, higher the risk of post-op lymphoedema
Who needs radiotherapy treatment in breast cancer?
=> All patients who undergo breast conserving surgery (wide local excision) for early breast cancer need post-op radiotherapy to ensure local control
=> Those undergoing mastectomy with disease close to resection margins need radiotherapy to the chest wall and regional lymph nodes
Risk of recurrence drops to <10% from 30% at 10 years and increases overall survival
Side effects: pneumonitis, percarditis, rib fracture
What is systemic therapy (chemotherapy) in breast cancer?
- Neoadjuvant therapy => downstage the cancer before surgery or radiotherapy
=> this allows safe breast conserving surgery in a patient with a disease that would originally require full mastectomy
- Adjuvant therapy given after surgery in patients who have high risk of relapse
=> aim is to destroy microscopic residual disease that may have disseminated
=> improves survival ; reduces recurrence
What is the role of HER-2 in breast cancer?
Human epidermal growth factor receptor 2 (HER-2) is over expressed in 20% of breast cancers and acts as an oncogene driving the cancer to grow.
HER-2 +ve breast cancers = aggressive but respond well to treatment
