Endocrine paraneoplastic syndromes in lung cancer: A call for clinical vigilance (Review)

Endocrine paraneoplastic syndromes (PNS) are uncommon but clinically impactful manifestations associated with malignancies, particularly lung cancer, most notably small-cell lung cancer. These syndromes arise from ectopic hormone production by malignant cells, causing systemic effects that are independent of direct tumor invasion or metastasis. Their presentation often precedes or signals recurrence of the primary cancer, underscoring the importance of early recognition and targeted intervention. Common endocrine PNS in lung cancer include syndrome of inappropriate antidiuretic hormone secretion, hypercalcemia, Cushing syndrome, carcinoid syndrome, and other hormonal imbalances such as non-islet cell tumor hypoglycemia, gynecomastia and acromegaly. The pathophysiology of these conditions involves ectopic secretion of bioactive substances such as hormones and cytokines, leading to diverse clinical manifestations. Accurate diagnosis necessitates a combination of biochemical assessments, imaging modalities, and histopathological evaluations to differentiate paraneoplastic processes from primary endocrine disorders. Management strategies emphasize treating the underlying malignancy, often through chemotherapy, radiotherapy, or surgical intervention, alongside symptomatic therapies tailored to the specific endocrine abnormality. Multidisciplinary care is critical for optimizing outcomes and enhancing patients' quality of life. The current review highlights the need for heightened clinical vigilance and a systematic approach to diagnosing and managing endocrine PNS in lung cancer. By fostering early detection and comprehensive management, clinicians can significantly improve prognostic outcomes for affected individuals.