The effect of radioiodine therapy – are we asking the right questions?

Ziel/Aim: We wanted to determine why cause-specific survival isn’t changed for papillary thyroid carcinomas with 1-10 mm and no lymph node metastasis after radio-iodine therapy while overall survival after 20 years is significantly improved.

Methodik/Methods: We searched the SEER Research Plus Data, 17 Registries, Nov 2023 Sub (2000-2021), released April 2024, based on the November 2023 submission, limited to patients with papillary thyroid carcinomas (ICD-O-3 8260/3) and 1-10 mm tumor size.

Ergebnisse/Results: A total of 36507 patients were analyzed and 27141 patients who received no radio-iodine vs 8644 radio-iodine included. We further refined our analysis to patients with no known lymph node metastasis (16104 vs 2836 patients). OS after 12, 36, 60, 120 and 240 months was 99.4, 98.3, 96.8, 91,9 and 77.3 vs 99.9, 99.3, 98.7, 95.2 and 85.3% for no-radio-iodine vs radio-iodine while CSS was 99.2 vs 99.4% after 20 years. When comparing these two populations for causes of death we found Odds-Ratios for some diseases increased and some decreased: in the radio-iodine group there were no complications from surgery, and risk of death from pneumonia, alzheimers, nephritis, diseases of arteries and diseases of the pancreas were significantly reduced (0, 0.48, 0.49, 0.50, 0.55, 0.6) while death by septicemia, diseases of the breast, chronic liver diseases, suicide, miscellaneous neoplasms, other B-cell or unspecified lymphomas was increased and most notably the risk of dying from a thyroid related disease was the most common cause of death (1.39, 1.40, 1.48, 1.49, 1.74, 2.35 and 3.13).

Schlussfolgerungen/Conclusions: The question of the usefulness of radio-iodine therapy is still open in the quidelines as an improvement of CSS is only noticeable for higher stage tumors (i.e. T4, M1). In lower stage tumors while the CSS remains almost the same after twenty years whether a patient was treated with radio-iodine or not the overall survival is improved due to other diseases like alzheimers. So: is radioiodine a thyroid specific treatment or is it more, something different entirely or is the effect confounded and radio-iodine is indeed useless in lower stage tumors?

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Artikel online veröffentlicht:
12. März 2025