Impact of nodal metastases on prognosis in patients with well-differentiated thyroid cancer.

OBJECTIVES: To study the clinical and pathological variables predicting lymph node metastases in patients with well-differentiated thyroid carcinoma and to examine the impact of these metastases on recurrence and survival.

DESIGN: Cohort study. Median follow-up, 56 months.

SETTING: Tertiary referral university teaching hospital.

PATIENTS: The study included 522 consecutive patients with well-differentiated thyroid carcinoma treated between 1964 and 1999. Data were collected on age, sex, family history of thyroid disease, prior radiation exposure, stage of disease, pathological diagnosis, size of tumor, multifocality of disease, recurrence, and survival.

INTERVENTION: Total thyroidectomy and postoperative iodine 131 ablation.

MAIN OUTCOME MEASURES: Disease-free and overall survival.

RESULTS: A total of 347 patients with stage I disease and 118 with stage II disease were identified. The median age of patients with neck disease was 3 years younger than those without neck disease and most had papillary carcinoma. Patients with multifocal disease were more likely to have neck disease (P =.02). On univariate analysis, disease-free and overall survival rates were significantly lower in patients who presented with neck node metastases (P<.001 and P =.005); this difference in survival remained highly significant on multivariate analysis for disease-free survival (P =.001), with a relative hazard of 6.27.

CONCLUSIONS: When treated with total thyroidectomy and routine postoperative iodine 131 ablation, patients with well-differentiated thyroid carcinoma who present with neck node metastases outside the central compartment of the neck have an approximately 6-fold risk of developing recurrences, most of which occur in the neck.