Chronic lymphocytic leukemia

It is one of the most common malignant hematological neoplasms, characterized by the uncontrolled proliferation of B lymphocytes. It is the most frequent subtype of leukemia in adults in Western countries, with an average incidence of 12 cases per 100,000 individuals per year, which increases exponentially with age and has a highly variable prognosis.

The exact causes that trigger the uncontrolled proliferation of B lymphocytes are unknown. Studies have identified significant chromosomal changes in the development of CLL, but it is still unclear which genes are involved or how they lead to leukemia. It has also been observed that DNA changes related to CLL often occur throughout a person's life, rather than being inherited from parents. However, the following factors have been described as increasing the risk of CLL:

• The disease mainly affects older adults, usually from the age of 60 onwards.
• It is slightly more common in men than in women.
• People of Caucasian descent are more likely to develop chronic lymphocytic leukemia than those of other backgrounds, such as Asians.
• Exposure to chemicals such as herbicides (Agent Orange) and insecticides or pesticides has been linked to a higher risk.
• Monoclonal B-cell lymphocytosis causes an increase in the number of these cells, which may promote the development of chronic lymphocytic leukemia.

More than 80% of patients with CLL do not present symptoms, and CLL is diagnosed through routine blood tests or by chance. In the remaining cases, the main symptoms may be:

• Asthenia, fatigue, weight loss.
• Lymphadenopathy or enlargement of the lymph nodes.
• Recurrent infections.

Occasionally, the spleen (splenomegaly) or liver (hepatomegaly) may become enlarged, causing abdominal discomfort. Unlike other blood cancers, fever, night sweats, and weight loss are uncommon.

There are very few known risk factors for chronic lymphocytic leukemia, and most of them cannot be avoided, aside from having first-degree relatives with the condition.