Prognostic Factors of Papillary Thyroid Carcinoma Vary According to Sex and Patient Age

We previously showed that preoperative and intraoperative evaluations of papillary thyroid carcinoma (PTC) are important for predicting a patient’s prognosis, and we identified several prognostic factors. In this study, we investigated differences in the significance of these factors according to patient age and sex.

A total of 5768 PTC patients (608 men, 5160 women) without distant metastasis at diagnosis who underwent initial surgery between 1987 and 2004 in Kuma Hospital were enrolled in this study. The postoperative follow-up period was 129 months (10.8 years) on average.

We examined variations in the prognostic significance of tumor size >4 cm (T), extrathyroid extension (Ex), node metastasis >3 cm (N), and extranodal (tumor extension (LN-Ex)—which were identified as prognostic factors in our previous studies—in four subsets of patients based on age and sex. In older women, Ex was the most significant prognostic factor for local and distant recurrences and carcinoma death. In older men as well, Ex was a strong prognostic factor, but N had a prognostic impact similar to Ex for local recurrence and LN-Ex was the strongest prognostic factor for carcinoma death. N was the most significant prognostic factor for local and distant recurrences and carcinoma death in younger women. T and N independently affected local recurrence with similar significance, and Ex was the only independent prognostic factor for distant recurrence in younger men. Because only two of the younger men in this series died of carcinoma, we could not analyze prognostic factors for carcinoma death in this subgroup.

The significance of prognostic factors of PTC varied according to patient sex and age, which might contribute not only to evaluating the prognosis but also to deciding therapeutic strategies for each patient. Because Ex was a prominent prognostic factor for local and distant recurrences in older patients, careful and extensive excision of the site of carcinoma extension and extensive lymph node dissection should be performed, especially for older patients with Ex.