The immune system
Some types of cancer are more likely to occur in people who have poor immunity.
People with a lower immunity may have:
had an organ transplant and are taking drugs to suppress their immune system to prevent the organ being rejected by the body
reduced immunity because of HIV (human immunodeficiency virus)
rare medical syndromes that reduce immunity.
People with poor immunity are more likely to develop lymphomas and certain types of skin cancer (particularly non-melanomas). They are also more at risk of cancers that are influenced by a virus or bacteria, such as cancers of cervix, some anal and genital cancers, and some cancers of the stomach and liver.