Multivariate analysis of risk factors influencing survival in 110 ethnic Chinese with papillary thyroid cancer.

Data from 110 Chinese patients presenting with papillary thyroid cancer to a single institution up to December 1985 have been analyzed to evaluate the possible risk factors affecting survival. There were 83 women and 27 men with an age range of 15 to 78 years (mean 45 years, median 42 years). The longest follow-up period is 39 years and the median 10 years. Cervical lymph node recurrence more than 6 months after surgery developed in 12 patients, of whom 1 died with a concomitant distant metastasis. "Thyroid bed" tumor recurrence, after apparently complete surgery, presented in 10 patients and resulted in 5 deaths. Distant metastases were identified in 17 patients with 7 deaths. Another 4 patients died from advanced local disease incompletely resectable on presentation. The following seven risk factors for survival were selected for multivariate analysis: age, sex, tumor size, histologic evidence of extrathyroidal spread, lymph node recurrence, neck recurrence, and distant metastases. Age, size, neck recurrence, and distant metastases were all significant on univariate analysis. Using Cox proportional hazards regression in the multivariate analysis of these seven factors, only age (p < 0.0001) was shown to be significant. Age over 40 years on first diagnosis was a highly significant indicator of high risk (p = 0.0003, log-rank).