breast cancer

Last edited 06/2023 and last reviewed 11/2023

• breast cancer is the most common type of cancer among women in the UK. Women have a one in nine lifetime risk of developing breast cancer
  
  
  • incidence of breast cancer increases with age, doubling every 10 years until menopause, after which the rate of increase slows down
    
    
  • breast cancer is the most common cancer in the UK, with approximately 54,000 new cases of invasive disease and around 7,000 new cases of pre-invasive (in situ) disease diagnosed annually
  • most of the breast cancers occur in women, but just over 300 men in the UK are also diagnosed with invasive breast cancer every year. Most breast cancers are diagnosed at an early stage and are therefore potentially curable with modern treatments
    
    
  • survival rates have improved over recent decades with almost 90% of women diagnosed with breast cancer surviving their disease for 5 or more years after diagnosis. Survival is, however, linked to the stage of the disease at diagnosis; only 15% of women diagnosed with stage IV disease are alive at 5 years
    • breast cancer remains the leading cause of death in women aged 35-49 years, and is second only to lung cancer as the leading cause of cancer death in all women.
      
      
• metastatic breast cancer is an advanced stage of the disease when it has spread to other organs
  • an estimated 5% of patients present with metastatic breast cancer, and approximately 30% of people who present with localised breast cancer will later develop metastatic breast cancer
  • common sites of metastasis include bone, liver, lung and brain.

Risk factors:

• main risk factor for breast cancer is being female; the disease is 100 times less common in men
  
  
• a disease of ageing, with the risk of breast cancer increasing with increasing age
  
  
• some breast cancers are linked to lifestyle factors that include obesity, alcohol intake and use of hormone replacement therapy, whereas other lifestyle factors, including physical activity and breastfeeding, protect against breast cancer
  
  
• about 5% of breast cancers are because of inherited mutations in high-risk genes such as BRCA1/2 and p53.

Taylor et al note:

• since the 1990s, the five year risk of death from breast cancer has decreased from 14.4% to 4.9% overall, with reductions seen in nearly all patient group

Reference:

• 1)NICE (June 2012). Lapatinib or trastuzumab in combination with an aromatase inhibitor for the first-line treatment of metastatic hormonereceptor- positive breast cancer that overexpresses HER2
• 2) NICE (June 2023). Early and locally advanced breast cancer: diagnosis and management
• 3) Taylor C, McGale P, Probert J, Broggio J, Charman J, Darby S C et al. Breast cancer mortality in 500,000 women with early invasive breast cancer in England, 1993-2015: population based observational cohort study BMJ 2023; 381 :e074684 doi:10.1136/bmj-2022-074684