What is CLL?

Chronic Lymphocytic Leukaemia (CLL) and Small Lymphocytic Lymphoma are related forms of non-Hodgkin lymphoma that are characterised by an accumulation of mature but abnormal B-lymphocytes (B cells). CLL affects bone marrow and blood while SLL primarily enlarges lymph nodes and lymphoid tissues. They are considered different expressions of the same disease, and management is often based on the predominant location of disease.

You can access further information about CLL, including risk factors, symptoms, diagnosis and treatment from Cancer Council Victoria. You can also call our trusted cancer nurses on 13 11 20 for support and to learn about our range of services for people affected by cancer.

The Victorian Cancer Registry also operates an interactive web portal, Data Explorer, which provides more trends and statistics than published here.

How common is CLL?

In 2024, 552 Victorians were diagnosed with CLL. Of these, there were 339 males and 213 females, representing 61% and 39% of the total Victorian CLL diagnoses, respectively. Currently, CLL is diagnosed at a rate of 8.4 per 100,000 males and 4.6 per 100,000 females. The median age at diagnosis of CLL is 70 years in males and 73 in females (Figure 1 & 2). Accounting for 1.4% of all cancers diagnosed and 0.69% of all cancer-related deaths in 2024, CLL was the 18th most commonly diagnosed cancer and the 26th most common cause of cancer-related deaths in Victoria in 2024.

Trends in CLL over time

Figure 3a shows for males between 2017 to 2024 the age standardised incidence rate of CLL declined by an average of 6% per year.

For females between 2016 to 2024 the age standardised incidence rate of CLL declined by an average of 5% per year.

The sharp rise in age-standardised incidence observed between 2013 and 2017 is artificial, resulting from improved detection of CLL by the Victorian Cancer Registry following the introduction of E-Path, an automated system for cancer notifications from pathology laboratories.

Geographical variance in CLL by local government area

Figure 4 demonstrates variation in the estimated risk of being diagnosed with CLL, by local government area, relative to the Victorian average. Red shading indicates areas with higher risk and blue shading indicates areas with lower risk relative to Victoria.

CLL in people born overseas

Figure 5 shows the standardised incidence ratios (SIRs) of CLL in Australian-born Victorians compared to other major migrant groups, over the five-year period 2019 to 2023. The highest standardised incidence ratio (SIR) for CLL was 1.2 for males born in the Other Europe region and the lowest SIR of 0.13 was observed in males born in the South-East Asia region. The highest standardised incidence ratio (SIR) for CLL was 1.9 for females born in the North America region and the lowest SIR of 0.14 was observed in females born in the North-East Asia region.

CLL five-year relative survival

Figure 6 shows the change in 5-year survival for CLL, and the 5-year survival trend for all cancers over the same time period. It demonstrates that five-year relative survival has increased for CLL between 1985-1989 and 2020-2024 from 61% to 90%.