Outcome of a conservative surgical policy for differentiated thyroid cancer: a prospective population‐based cohort study

Background The extent of surgery and the requirement for routine total thyroidectomy in patients with papillary or follicular differentiated thyroid cancer (DTC) is contentious. It is desirable to strike a balance between achieving cure and local disease control and avoidable surgical morbidity. Routine total thyroidectomy increases the rate of permanent hypoparathyroidism and may not improve cure or local recurrence rates in patients categorized at low risk. An ongoing prospective study of the outcome of a conservative surgical policy based on an unselected population from the north east of Scotland is reported. Methods With few exceptions, all patients with thyroid cancer in north‐east Scotland are treated in a specialist unit. Data are recorded prospectively and all patients are reviewed at a dedicated thyroid clinic or by postal review if they leave the area. The mortality, morbidity (including recurrent laryngeal nerve and parathyroid function), recurrence and reoperation rates, and administration of radioactive iodine are recorded. The population of this region is very stable and follow‐up is complete in over 97 per cent of patients. The surgical policy is to remove all macroscopic disease from the neck at the first operation and reserve total thyroidectomy for patients with bilateral disease or who are considered at high risk and likely to require postoperative radioactive iodine therapy. Results During the period 1977–1996, 238 patients with thyroid cancer were treated of whom 193 (81 per cent) had DTC. Some 148 (77 per cent) of the DTCs were categorized ‘low risk’. Fifty‐five (28 per cent) of the 193 patients underwent total or near‐total thyroidectomy. The majority of patients (75 per cent low risk; 59 per cent high risk) underwent lobectomy. Seven patients (five low risk; two high risk) have required subsequent completion total thyroidectomy, usually for a rising thyroglobulin level, only three of whom had evidence of DTC in the resected lobe. The mortality rate from DTC was 13 and 1 per cent in high‐ and low‐risk patients respectively. Four (2 per cent) of the 193 patients developed postoperative hypoparathyroidism. Conclusion This prospective study suggests that appropriate selection of patients for total thyroidectomy in an endocrine surgical unit is associated with a low mortality rate and little requirement for completion total thyroidectomy. Routine total thyroidectomy is not necessary. © 2000 British Journal of Surgery Society Ltd