Breast: Breast Cancer Flashcards
What is the most common type of breast cancer?
Adenocarcinoma (95%): derived from epithelial cells found in terminal duct lobular unit.
Suggest risk factors for breast cancer.
- women
- increasing age
- previous breast cancer or ovarian, endometrial or bowel cancer
- family history (3% breast cancers are familial, of which 25% are attributed to BRCA1/2)
- irradiation to chest wall
- increased oestrogen exposure, e.g. early menarche (<13 yrs), late menopause (>51 yrs), nulliparity, having 1st child >30 yrs, HRT, COCP, obesity
What breast changes might be seen in breast adenocarcinoma?
- progressively enlarging non-tender lump
- skin changes, e.g. dimpling, peau d’orange, or Paget’s-like disease
- nipple changes, retraction or discharge
- breast asymmetry or swelling
How might a breast adenocarcinoma feel like on examination?
- hard consistency
- irregular surface
- indistinct borders
- immobile
- may be tethered to overlying skin or underlying muscle
+/- palpable lump in axilla
How are breast lumps classified using triple assessment?
- Examination - P1-5: P1 normal, P2 benign, P3 uncertain, P4 suspicious, P5 malignant
- Imaging
- USS (<35yrs) - U1-5
- mammogram (>35yrs) - M1-5 - Biopsy - B1-5
- fine needle aspiration
- core biopsy
Which features of a lesion on mammogram are suggestive of cancer?
- increased density
- irregular margins
- spiculations (shards of glass)
- accompanying clustered irregular microcalcifications
Which investigations would you perform for staging of breast cancer?
- Lung mets: chest x ray
- Liver mets: abdo palpation, liver enzymes, liver USS
- Bone mets: palpation for sites of bony tenderness, serum calcium and phosphate, and isotope bone scan or MRI
- CT head scan if Sx suggestive of brain mets (e.g. fitting, early morning headaches, nausea)
What is carcinoma in situ? What are the 2 different types?
CIS = malignancies contained within the basement membrane tissue. ‘Pre-malignant’, rarely symptomatic at presentation.
- Ductal carcinoma in situ (DCIS)
- most common type of non-invasive breast malignancy (20% of all breast cancers)
- 20-30% untreated cases will develop invasive disease (e.g. axillary node metastasis)
- often detected during screening - appear as microcalcifications - Lobular carcinoma in situ (LCIS)
- malignancy of secretory lobules of breast, much rarer than CIS, but greater risk of developing invasive malignancy
- usually asymptomatic and not associated with microcalcifications (often incidental finding on breast biopsy)
Describe the classification of invasive breast cancers.
Almost all cancers arise in terminal duct lobular units but classification remains in use due to different behaviours of subtypes:
- invasive ductal carcinoma (80%)
- invasive lobular carcinoma (10%)
- other, e.g. medullary or colloid carcinomas
What are the 3 main surgery options for breast cancer? When is each recommended?
- WIDE LOCAL EXCISION (breast conserving)
- excision of tumour, ensuring 1cm margin of macroscopically normal tissue taken with malignancy
- for localised operable disease (<4cm diameter) with no evidence of metastatic spread, e.g. localised DCIS - MASTECTOMY
- removes all tissue of affected breast with significant portion of overlying skin
- for localised invasive cancer, or pt choice, e.g. widespread DCIS or LCIS + BRCA1/2 (bilateral prophylactic) - Axillary surgery: SENTINEL NODE BIOPSY (1-2 LNs), AXILLARY NODE SAMPLING (4 LNs) or AXILLARY NODE CLEARANCE (all LNs)
- commonly performed alongsie WLE and mastectomies to assess sentinel LN and indicate disease progression
What is the typical chemotherapy regimen? When is it recommended?
Combination of anthracycline, 5-fluorouracil and cyclophosphamide, given in 4-6 cycles every 6 weeks.
Aim to reduce annual risk of relapse, esp. in younger, LN +ve, high grade, VI +ve disease (>T2, >G2, >N1).
When is hormonal therapy recommended?
Given to all women with ER +ve or PR +ve tumours (>70%):
- primary treatment in elderly pts or those unfit for surgery
- adjuvant therapy in malignant non-metastatic disease to reduce risk of relapse
What are the 2 main types of hormone therapy? What is their MOA?
- Aromatase inhibitors: anastrozole, letrozole, exemestane
- bind oestrogen Rs to inhibit further malignant growth and prevent further oestrogen production
- also block conversion of androgens to oestrogen in peripheral tissues - Tamoxifen (SERM)
- blockade of oestrogen Rs
Name an example of immunotherapy used in breast cancer.
Herceptin (Trastuzumab): mAb that targets the human epidermal growth factor receptor (HER-2).
Used as adjuvant therapy in 20-25% of breast cancers that over-express HER-2 protein on cell surface, or as monotherapy in patients who have received at least 2 chemotherapy regimens for metastatic breast cancer.
What is the Nottingham Prognostic Index (NPI)?
NPI = (size tumour cms x 0.2 + grade 91-111) + lymph node status
Nodal status is single most important prognostic factor in breast cancer, although size, grade and R status also influence prognosis.
