Thyroid Research Thyroid Research Archive Thyroid Cancer

More extensive surgery and radioiodine therapy have had limited benefit in patients with papillary thyroid carcinoma

(November 2002)

The background of the study. This study determined the changes in therapy and the mortality and tumor recurrence rates in a large cohort of patients with papillary carcinoma.

How the study was done. The study subjects were all 2444 patients (mean age, 46 years) with papillary carcinoma who were operated on at the Mayo Clinic from 1940 to 1999. The median follow-up was 15 years (longest, 60 years). Among the patients, 2305 (94 percent) were considered cured after initial surgery.

The results of the study. The initial operation was a near-total or total thyroidectomy in 1905 patients (78 percent), bilateral subtotal lobectomy in 215 patients (9 percent), unilateral lobectomy in 284 patients (12 percent), and lesser operations in the remainder. After surgery, 774 patients (33 percent) received radioiodine therapy. Radioiodine was not given during the 1940s; but thereafter, the rates increased from 4 percent in the 1950s to 18 percent in the 1970s to 46 percent in the 1990s. Risk status was not a determinant of radioiodine therapy; in the 1980s and 1990s approximately 50 percent of patients at low and high risk of recurrence were given radioiodine.

Among the 2305 patients thought to be cured after initial surgery, 673 (29 percent) died-a rate similar to that expected for people living in the same region. The mortality rates due to cancer were 5 percent at 15, 20, and 25 years. The tumor recurrence rates at these times were 12, 13, and 14 percent, respectively. Despite the differences in extent of surgery and frequency of radioiodine therapy, the 10-year cancer-specific mortality and recurrence rates did not vary in either the low-risk or high-risk patients from 1950 to 1999.

The conclusions of the study. Recurrence and cancer-specific death rates in patients with papillary thyroid carcinoma have changed little since 1950, despite more extensive surgery and more frequent radioiodine therapy.

The original article. Hay ID, Thompson GB, Grant CS, Bergstralh EJ, Dvorak CE, Gorman CA, Maurer MS, McIver B, Mullan BP, Oberg AL, Powell CC, van Heerden JA, Goellner JR. Papillary thyroid carcinoma managed at the Mayo Clinic during six decades (1940-1999): temporal trends in initial therapy and long-term outcome in 2444 consecutively treated patients. World J Surg 2002;26:879-85.