Incidence: affects 1 in 12 women in the UK.

There are 20 000 new patients per year in the UK. The incidence is rising but themortality is falling, however there are still about 15 000 deaths from this cancer per year.

Age: it is very rare under the age of 30, incidence increases with age.

Geography: disease of developed countries.

Aetiology/risk factors:

1. Early menarche, late menopause

2. First child over 30 years

3. Family history in first-degree relatives

4. Previous breast cancer

5. Radiation exposure

6. Exogenous hormones

7. High intake of saturated fats, alcohol.

Pathology

Tumour type:

1. 1. Non-invasive ductal carcinoma in situ (CIS) – this is a premalignant condition that can be seen as microcalcification on mammography. This can be unifocal (indicating a localized removal or lumpectomy) or widespread (which may require a mastectomy).

2. 2. Non-invasive lobular CIS.

3. 3. Invasive ductal – this is the most common. The lump feels hard (‘scirrhous’).

4. 4. Invasive lobular.

5. 5. Medullary – 5% of breast cancers. The tumour is soft, and it tends to affect younger patients.

6. 6. Colloid/mucinous – occur in the elderly. May mimic a benign mass on mammogram.

7. 7. Papillary.

8. 8. Paget's – this is a superficial presentation of an underlying cancer and it appears as an eczema-like condition of the nipple. Importantly this persists, therefore all eczema of the nipple lasting >2 weeks should be biopsied.