Risk Factors for Differentiated Thyroid Carcinoma in Long-Standing Goiter: A Bolivian Clinical-Demographic Study

Abstract

Introduction: In endemic areas such as Bolivia, differentiated thyroid cancer (DTC) in patients with chronic goiter poses a diagnostic challenge. The objective was to describe the clinical factors associated with the presence of DTC in patients undergoing surgery for long-standing goiter at a tertiary care hospital.

Methods: This observational, descriptive, retrospective study (2014–2024) included 193 patients who underwent surgery for goiter at Hospital San Juan de Dios (Santa Cruz, Bolivia), with histopathological confirmation of DTC in 76 cases. Logistic regression was used to analyze clinical, demographic, and diagnostic variables, and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated.

Results and discussion: Five relevant clinical factors were identified (p < 0.05), with a malignancy (DTC) rate of 42% in the surgical cohort. Adherence to deep tissue planes or hard consistency was the most relevant factor (85.5% of cases; OR 6.66; 95% CI: 3.19–13.89), followed by rapid growth during the previous year (72.4%; OR 5.89; 95% CI: 3.54–12.84) and urban origin or migration more than 10 years previously (72.4%; OR 2.5; 95% CI: 1.34–4.62). Significant associations were also observed with cytological findings (Bethesda ≥ IV; OR 6.69) and imaging findings (TI-RADS ≥ IV; OR 3.5). In the multivariable regression analysis, adherence to deep tissue planes was the only independent variable (p = 0.024). The association with urban origin could be related to environmental factors or greater access to diagnostic testing.

Conclusion: In this series of patients undergoing surgery for chronic goiter, the presence of a mass adherent to deep tissue planes, urban origin, and higher TI-RADS/Bethesda categories were associated with DTC. These findings could contribute to improving criteria for surgical referral in endemic areas with limited resources. Further studies are needed to explore local environmental and geochemical factors and their possible relationship with thyroid carcinogenesis.

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