ALL is one of the four major leukaemias that affect adults. Their incidences and the approximate number of patients diagnosed every year in the United Kingdom (UK) are shown in Table 1.
Table 1
Main leukaemia and their incidences in the UK (2016-2018)
| Leukaemia type in adults | Incidence per 100,000 people | No of UK patients affected per year |
| Acute lymphoblastic leukaemia (ALL) | 1.1 | 791 |
| Acute myeloid leukaemia (AML) | 4.9 | 3089 |
| Chronic lymphoblasticcytic leukaemia (CLL) | 6.2 | 3803 |
| Chronic myeloid leukaemia (CML) | 1.3 | 829 |
- ALL occurs mainly in childhood with 85% of cases compared with only 15% of cases in adults (National Health Service 2019). Although ALL is most common in children around 5 years of age, there is another peak in incidence in adults around 50 years of age. This e-learning module will concentrate on ALL in adults.
- In the United Kingdom, the incidence of ALL per 100,000 adults per year increases with age):
o 0.7 at 60–64 years of age
o 1.0 at 70–74 years of age
o 1.3 at over 99 years of age
- ALL is an aggressive leukaemia in which immature, abnormal lymphocytes start multiplying uncontrollably, resulting in an increase of their numbers in the blood and bone marrow.
- ALL develops rapidly and gets worse quickly if it is not treated. Chronic leukaemia on the other hand develops steadily and progresses slowly.
- These immature abnormal lymphocytes cells are called ‘leukaemia cells’ and they can spread to the lymph nodes, spleen, liver, central nervous system (CNS) and other organs.
- Lymphocytes are one of the types of white blood cell that help fight infections as part of the immune system.
