The causes of most low-grade lymphomas are not fully understood, and there are currently no clear prevention strategies. Some low-grade lymphomas such as gastric MALT are, however, preventable through identification and eradication of Helicobacter pylori infection.

The risk factors in common across all low-grade indolent lymphomas include the following:

• Age – incidence of low-grade lymphomas increases with age
• Obesity – high BMI in adulthood and early adulthood may increase the risk of low-grade lymphomas (Abar et al. 2019)
• Family history – individuals with a first-degree relative (parent, child, sibling) with a low-grade lymphoma have a small increased risk of developing NHL
• Race/ethnicity – there is a higher incidence of indolent NHL in white Caucasian populations compared with non-Caucasian ethnicities
• Radiation exposure – patients treated with radiation for other cancers have slightly increased risk of developing a low-grade This risk is greater for patients treated with both radiation therapy and chemotherapy
• Weakened immune system – people with weakened immune systems as a result of immunosuppressive drugs, chronic infection or some genetically inherited syndromes are at a higher risk of developing a low-grade lymphoma
• Autoimmune diseases – people with autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, Sjogren’s disease and coeliac disease may have an increased risk of developing a low-grade lymphoma
• There is a possible association between exposure to glyphosate-based agricultural pesticides and risk of developing a low-grade lymphoma, but a lack of prospective studies limits definitive

Follicular lymphoma

• Gender – women have a slightly higher risk of developing FL than men
• Race/ethnicity – FL occurs more commonly in Caucasian populations
• Viral infections – viruses that have been implicated in developing FL include Epstein-Barr virus, human T-cell lymphotropic virus type I and Kaposi sarcoma-associated herpesvirus

MALT lymphomas

MALT lymphomas, in particular, are associated with a variety of infectious/autoimmune disorders:

• 90 per cent of gastric MALT lymphoma are associated with Helicobacter pylori gastritis
• Ocular adnexal MALT lymphoma may be associated with Chlamydia psittaci
• Cutaneous MALT lymphoma may be associated with Borrelia burgdorferi
• MALT lymphoma of the small intestine and immunoproliferative small intestine disease may be associated with Campylobacter jejuni
• Thyroid MALT may be associated with Hashimoto’s thyroiditis
• Salivary gland MALT may be associated with Sjogren’s syndrome
• SMZL may be more common in those with chronic hepatitis C infection and associated with autoimmune conditions such as haemolytic anaemia and immune

Mantle cell lymphoma

• Gender – men have a greater risk of developing MCL than

Everyone should be encouraged to reduce their modifiable risk factors for cancer, including preventing and/or reducing obesity, alcohol consumption, tobacco smoking and exposure to pesticides, which may be associated with slight increased risk.

Routine screening for lgl is not currently recommended in either the general population or in relatives of people with lgl.