Prognosis after lymph node recurrence in papillary thyroid carcinoma depends on age

Papillary thyroid carcinoma (PTC) is a malignancy that has good prognosis especially among patients up to 45 years of age; about half of the patients are female and of childbearing age. Lymph node recurrence (LNR) occurs in 10%-14% of patients but is considered to be associated with relatively good prognosis. The purpose of this study was to estimate the association between patient age at primary operation, and the behavior of the disease after LNR. Between 1967 and 1994, 495 patients underwent surgery for primary PTC at the Department of Surgery, Helsinki University Central Hospital. There were 391 (79.0%) women and 104 (21.0%) men with a mean age of 44.5 years (range, 10.8-85.4 years). Fifty-eight patients in whom LNR was the first clinical sign of persistent disease after complete clinical response to primary treatment were included in this series. At the time of primary operation, 37 (64.3%) of the 58 patients who developed LNR were younger than 45 years of age and 21 patients were older. The mean times to LNR in these groups were 42.0 months (range, 3.0-194.5 months) and 49.0 months (range, 3.6-209.0 months) respectively. Carcinoma-specific 5-year survival after LNR was 100% (95% confidence interval [CI] 88.8%-100.0%) in patients ages up to 45 years and 61.1% (40.5%-82.8%) in older patients; 10-year survival rates were 100%, and 41.3% (p < 0.0001), respectively. Relative survival at 10 years was 98.6% for patients ages up to 45 years and 42.6% for older patients (p = 0.0014). Using the Cox model it was shown that development of LNR after primary treatment has an independent highly significant negative effect on survival (p < 0.001) in patients over 45 years of age. Prognosis of PTC even after LNR on patients ages up to 45 years at the time of the primary operation is almost parallel to the normal reference population, but in patients over 45 years of age the prognosis is relatively poor.