Through use of medical records and Medicare claims, researchers discovered the risk of non-Hodgkin lymphoma (NHL), late in life, was 29 times greater in those with ME/CFS. The risk of other forms of cancer did not appear to be elevated.
Researchers hypothesize that chronic immune activation or an infection may be responsible for the link, as these are things that are known to contribute to cancer's development. Chronic immune activation is an established component of ME/CFS, but the medical community is split on whether infections are involved and what role they play in the illness.
This study looked only at people between the ages of 66 and 99. The positive link may lead to further investigation.