Background: The National Cancer Data Base (NCDB) represents a national electronic registry system now capturing nearly 60% of incident cancers in the U. S. In combination with other Commission on Cancer programs, the NCDB offers a working example of voluntary, accurate, cost-effective "outcomes management" on a both a local and national scale. In addition, it is of particular value in capturing clinical information concerning rare cancers, such as those of the thyroid.
Methods: For the accession years 1985-1995, NCDB captured demographic, patterns-of-care, stage, treatment, and outcome information for a convenience sample of 53,856 thyroid carcinoma cases (1% of total NCDB cases). This article focuses on overall 10-year relative survival and American Joint Committee on Cancer (AJCC) (3rd/4th edition) stage-stratified 5-year relative survival for each histologic type of thyroid carcinoma. Care patterns also are discussed.
Results: The 10-year overall relative survival rates for U. S. patients with papillary, follicular, Hürthle cell, medullary, and undifferentiated/anaplastic carcinoma was 93%, 85%, 76%, 75%, and 14%, respectively. For papillary and follicular neoplasms, current AJCC staging failed to discriminate between patients with Stage I and II disease at 5 years. Total thyroidectomy +/- lymph node sampling/dissection represented the dominant method of surgical treatment rendered to patients with papillary and follicular neoplasms. Approximately 38% of such patients receive adjuvant iodine-131 ablation/therapy. At 5 years, variation in surgical treatment (i.e., lobectomy vs. more extensive surgery) failed to translate into compelling differences in survival for any subgroup with papillary or follicular carcinoma, but longer follow-up is required to evaluate this. NCDB data appeared to validate the AMES prognostic system, as applied to papillary cases. Younger age appeared to influence prognosis favorably for all thyroid neoplasms, including medullary and undifferentiated/anaplastic carcinoma. NCDB data also revealed that unusual patients diagnosed with undifferentiated/anaplastic carcinoma before age of 45 years have better survival.
Conclusions: The NCDB system permits analysis of care patterns and survival for large numbers of contemporaneous U. S. patients with relatively rare neoplasms, such as thyroid carcinoma. In this context, it represents an unsurpassed clinical tool for analyzing care, evaluating prognostic models, generating new hypotheses, and overcoming the volume-related drawbacks inherent in the study of such neoplasms. [See editorial on pages 2434-6, this issue.]