Paraneoplastic neurological syndromes in patients affected by SCLC: a case series

Paraneoplastic syndromes occur in about 0.1% of patients affected by neoplastic diseases. In some types of tumors, such as Small Cell Lung Cancer (SCLC), Thymoma, and particular forms of Plasmacytoma, the association with Paraneoplastic Neurological Syndromes (PNS) is much more frequent. It seems that these syndromes are triggered by tumor production of factors normally expressed only by the individual's nervous system. The immune system stimulates an autoimmune response against these factors that induce neurological symptoms. Also, in light of the latest updates on the relationship between immunotherapy and PNS as well as of the introduction of first-line immunotherapy in SCLC, it seems that the use of immunotherapy in SCLC is associated with concomitant increase in autoimmune neurological syndromes. In this article, we report our experience at Istituto Nazionale Tumori of Milan with three patients affected by SCLC and PNS. Our experience seems to confirm that the oncological treatment scarcely impacts the paraneoplastic neurological deficits. Further research is needed to improve the treatment and recovery of patients affected by PNS.