Predictors of prognosis defined in recurrent thyroid carcinoma

Recurrence of a well-differentiated thyroid carcinoma significantly reduces survival but less than 50% of patients will be killed by the cancer in the following 20 years, according to an analysis of more than 500 Canadian patients in the Archives of Otolaryngology Head and Neck Surgery.Actuarial 20-year disease-specific survival was 100% for patients with no recurrence, 94% for those with a single recurrence, and 60% for those with multiple recurrences. Male sex, advanced stage and extrathyroidal spread at diagnosis, and primary treatment with total thyroidectomy all predicted multiple recurrences. "This knowledge is important in the counselling of every patient with primary or recurrent well-differentiated thyroid carcinoma regarding the extent of therapy and the importance of careful and regular lifelong follow-up," the report concluded.Well-differentiated thyroid carcinoma accounted for about 2% of all cancers but fewer than 0.5% of cancer deaths. Combination therapy with surgery and adjuvant iodine 131 resulted in overall 10-year survival rates of more than 90%. Despite best practice, recurrence rates of 8% to 23% had been reported. A recurrence was widely accepted as increasing the risk of subsequent recurrences, for reasons including progression to an undifferentiated tumour, lack of iodine 131 uptake, and a significant risk of leaving behind microscopic disease after salvage surgery. "However, long-term survival is possible in patients with persistent and recurring disease," the report said.A number of prognostic instruments were already well established for assessing the likely course of a primary carcinoma, but there had been little information on outcomes after recurrence.Reference...