Chronic lymphocytic leukemia

Incidence in Minnesota:

Chronic lymphocytic leukemia has slightly increased in Minnesota

The chronic lymphocytic leukemia (CLL) incidence rate in Minnesota has decreased since 2005, with an annual change of 1.2%. As with national data, incidence rates are about two times higher in males than in females. Minnesota incidence rates are among the highest in the nation in recent years, about 60% higher than national rates. Since CLL is often an "accidental finding" of other medical tests, higher rates in Minnesota may be explained in part by good access to medical care. 

Many CLL patients are never seen in a hospital. The higher than average incidence of CLL in Minnesota may be explained in part by the fact that the Minnesota Cancer Reporting System (MCRS) is laboratory-based and has more complete case ascertainment than central cancer registries that are primarily hospital-based. From 2016 to 2018, an average of 280 cases of CLL in males and 147 cases of CLL in females were diagnosed in Minnesota residents each year.

Chronic lymphocytic leukemia in Minnesota

Age-adjusted rate of new CLL cases.
Age-adjusted rate of new CLL cases.


The rate of CLL is two times higher among males than females. In males, CLL incidence increased by about 2.0% per year between 1988 and 2007 and decreased 1.4% per year since then. Most recently, the age-adjusted incidence rate of CLL was 8.6 new cases per 100,000 males and 4.1 new cases per 100,000 females.

Chronic lymphocytic leukemia in Minnesota, by age

Rate of new CLL cases, aggregated from 2009 to 2018.
Rate of new CLL cases, aggregated from 2009 to 2018.


CLL is extremely uncommon among children and young adults. Over the last 10 years, less than 10 Minnesotans under the age of 35 were diagnosed with CLL. Rates increase steadily with age for each sex.

What is chronic lymphocytic leukemia (CLL)?

Leukemia is a cancer of white blood cells. Chronic lymphocytic leukemia (CLL) is one type of leukemia. There are different types of CLL. Distinguishing among them is important for treatment decisions and prognoses. Current estimates are that more than 50% of CLL patients are diagnosed "incidentally" from blood work conducted for a different complaint. Symptoms, if present, may include painless swelling of the lymph nodes, fatigue, fever and infection, and/or unexplained weight loss. People can live many years with CLL and have few or no symptoms.

What are the risk factors for CLL?

There are few established risk factors for CLL.

  • Age: The incidence of CLL increases with age and is rare among children (in contrast to acute leukemia).
  • Race: white people are more likely to develop CLL than are people of other races.
  • Specific herbicides and insecticides including Agent Orange (used during the Vietnam War), have been linked to an increased risk of CLL. These pesticides likely account for a small proportion of CLL cases.
  • Family history of blood and bone marrow cancers.

How can CLL be prevented?

There are currently no practical strategies for preventing CLL.


Last updated May 2021. Updates are made when data become available.