Lung metastases from differentiated thyroid carcinoma. A 40 years' experience.

Aim. Retrospective studies have been carried out to estimate the survival of 96 patients with lung metastases from differentiated thyroid carcinoma, observed from 1958 to 2000. Methods. All patients had undergone total thyroidectomy. Case histories were analysed with respect to age at diagnosis, sex, histology, local lymph node involvement, size of lung metastases and 1 3 1 I uptake by metastases. Survival functions were calculated. Cox regression was performed. Results. There was no statistically significant difference in histological type and lymph node involvement, whereas a significantly longer survival time was observed in patients under 45 years of age at diagnosis (p≤0.0001), in those with metastases concentrating 1 3 1 I (p<0.0001) and in those with fine miliaric metastases (p=0.0037). Multi-variate analysis revealed that the risk of death increases about 5.4-fold in patients over 45 years old, whereas 1 3 1 I treatment is likely to reduce this risk to nearly 1/6. Conclusion. In conclusion, in patients with lung metastases from differentiated thyroid carcinoma, young age at diagnosis and 1 3 1 I uptake by metastases are the most important factors positively affecting survival time. Radioiodine therapy, also with high cumulative 1 3 1 I activity, can lead to longer survival time or complete recovery.