The most common form of cancer in the UK. Mostly affects women and is rare in men (1% cases)

About 1/8 people diagnosed with breast cancer in their lifetime

Most common area - superior lateral quadrant

Risk Factors

• Female (99% of breast cancers)
• Increased oestrogen exposure (earlier onset of periods and later menopause)
• More dense breast tissue (more glandular tissue)
• Obesity
• Smoking
• Family history (first-degree relatives)

Medications:

• Combined oral contraceptive pill - risk returns to normal 10 years after stopping pill
• HRT - Increased risk of breast cancer, particularly combined HRT (oestrogen+prog)

Genetics

BRCA gene - tumour suppressor gene. Mutations in these genes = increased risk of breast ca (+ovarian cancers and othe cancers)

There is a 50/50 chance of siblings and children of BRCA1 carrier to also have the gene

The BRCA1 gene is on chromosome 17. In patients with a faulty gene:

• Around 70% will develop breast cancer by aged 80