Breast Cancer

Question 1

What is the epidemiology of breast cancer?

Answer 1

Affects 1/8 women (rare in men)

Question 2

What are some risk factors for breast cancer?

Answer 2

BRCA genes - 5-10% are due to BRCA1/A2 mutations

(i) BRCA1 = 65% lifetime risk breast cancer, 40% ovarian cancer; 40-60% chance of developing a second breast cancer
(ii) BRCA2 = 45% lifetime risk breast cancer, 11% ovarian cancer
- Both are tumour suppressor genes
- Uninterrupted oestrogen exposure - nulliparous or 1st pregnancy >30yrs; early menarche; late menopause; HRT
- Obesity
- Not breastfeeding
- Past breast cancer
- Age

Question 3

What is the pathophysiolgoy of breast cancer?

Answer 3

Types

i) Invasive ductal carcinoma = most common
ii) Invasive lobular carcinoma
iii) Non-invasive ductal carcinoma-in-situ (DCIS)
iv) Non-invasive lobular CIS
v) Medullary cancer
vi) Colloid/mucoid cancer
- 60-70% are oestrogen receptor positive
i) Gives better prognosis
- 30% express HER2 (growth factor receptor gene)
i) Associated with aggressive disease and worse prognosis

Question 4

How does breast cancer present?

Answer 4

Usually early(ish) with a lump in the breast 
Poss also: inverted nipple, dimpling of skin, bloody discharge

Question 5

When are you invited for screening?

Answer 5

Every 3 years, between 47-73yrs old - 2 view mammography

For BRCA1/2 carriers – annual MRI surveillance is better than mammography in women <50 - bilateral prophylactic mastectomy can reduce incidence by 90%

Question 6

How is a lump assessed?

Answer 6

Triple assessment

i) Clinical examination
ii) Radiology – USS for <35yrs; mammography + USS >35yrs - USS better for invasive cancers, mammography better at DCIS
iii) Histology/cytology – US guided biopsy

Question 7

What are the potential findings/plans?

Answer 7

Cystic lump
- Aspirate → If bloody then cytology; If clear then reassure
- Residual mass → core biopsy
Solid lump
- Core biopsy → Malignant → plan treatment; Non malignant → reassure

Question 8

What is a sentinel node biposy?

Answer 8

i) Sentinel node = hypothetical first lymph node or group of nodes that drain a cancer → these are the sites most likely to be affected by a metastasising cancer
ii) Procedure involves injecting blue dye or radiocolloid into the tumour for visual/radiological visualisation of the node → identified and biopsied → cytology/histology etc
iii) Aims to reduce unnecessary axillary node clearance in those without affected lymph nodes

Question 9

How is breast cancer staged?

Answer 9

1 – confined to breast, mobile
2 – confined to breast, mobile, ipsilateral axillary lymph node involvement
3 – fixed to muscle but not chest wall, ipsilateral axilalry lymph node involvement, skin involvement
4 – complete fixation to chest wall, distant metastases

(OR TNM)

Question 10

What surgical options are there to treat stages 1-2?

Answer 10

Lumpectomy with wide local excision (WLE) or mastectomy ± breast reconstruction
± axillary node clearance or sentinel node biopsy

Question 11

What cancer treatments are there to treat stages 1-2?

Answer 11

Radiotherapy

• For all patients with invasive cancer after a WLE → reduce recurrence
• Also for axillary nodes if affected but not cleared (SE: lymphodema, brachial plexopathy)

Chemotherapy

• Adjuvant – reduces recurrence and improves survival
• Epirubicin + CMF (cyclophosphamide + methotrexate + 5-FU)

Question 12

What hormonal treatments are there to treat stages 1-2?

Answer 12

To reduce oestrogen activity
- Used in oestrogen + progesterone receptor positive cases (ER+, PR+)
- Tamoxifen - ER blocker
- Aromatase inhibitors targeting peripheral oestrogen synthesis – anastrozole - only in post menopausal
GnRH analogues – goserelin – reduce recurrence and increase survival - only in pre menopausal ER+ve

Question 13

What treatments are there for stage 3-4?

Answer 13

i) Staging using CXR/bone scan/MRI/PET etc
ii) Radiotherapy to bony lesions + bisphosphonates (to decrease pain and fracture risk)
iii) Tamoxifen in ER+
iv) Trastuzumab in HER+ tumours + chemo