Abstract
BACKGROUND: Cutaneous melanoma is a rising global health concern and identifying modifiable or associated risk factors remains essential for improving prognostic stratification. Hypothyroidism, affecting approximately 5.1% of the general population in Germany, has been associated with various malignancies. This study investigates the prevalence and potential prognostic implications of hypothyroidism in melanoma patients. METHODS: We conducted a retrospective single-centre study including 1553 patients with cutaneous melanoma (AJCC stages I-III). Patients were stratified based on thyroid function into hypothyroid and euthyroid groups. Data were collected via clinical records and standardized patient questionnaires. RESULTS: Hypothyroidism was documented in 234 patients (15.1%), significantly higher than the national prevalence (5.1%, p < 0.001). Tumor site differed significantly between groups, with hypothyroid patients more frequently exhibiting melanomas on the lower extremities (p < 0.001). These patients also showed a non-significant trend toward lower Breslow thickness (p = 0.09) and a significantly reduced number of metastatic lymph nodes (p = 0.009). CONCLUSIONS: Our findings suggest that hypothyroidism is markedly more prevalent among patients with cutaneous melanoma and may be associated with clinical features linked to improved prognosis. These observations warrant further investigation to clarify whether hypothyroidism itself, or its underlying immunologic and hormonal milieu, plays a protective role in melanoma progression.