NEW YORK (Reuters Health) – The rate of incidental thyroid cancer detected among patients who undergo thyroidectomy for apparently benign disease is unexpectedly high, especially in cases of nodular disease, according to a multicenter researcher team.
“These data support consideration of initial total thyroidectomy as the preferred approach for patients referred to the surgeon with bilateral nodular disease,” they suggest.
The findings come from an analysis of data on 2,551 patients who underwent thyroidectomy at high-volume centers in Tennessee, Wisconsin and Florida. On fine-needle biopsy, 1028 were found to have malignant or indeterminate disease; that is, a cytology diagnosis of malignancy, suspicious for malignancy, follicular lesion or atypia of undetermined significance, and follicular neoplasms.
In the remaining 1,523 patients with presumed benign disease, however, 238 incidental cancers were recorded after thyroidectomy on final pathology, Dr. Carmen C Solorzano, at Vanderbilt University Medical Center in Nashville, Tennessee and colleagues report in the Journal of the American College of Surgeons online February 11.
Incidental cancer rates were significantly higher in the 1,095 patients with nontoxic multinodular goiter (17.5%) and the 164 with toxic nodular goiter (18.3%) than in the 264 Graves’ disease patients (6.1%; p<0.01), according to the report.
The presence of lymphocytic thyroiditis was not associated with incidental cancer, but multivariate analysis indicated that younger patients, males, and nodular thyroids were more likely to harbor carcinoma, the investigators found.
They note that the overall incidental cancer rate of 15.6% was higher than has been reported in similar studies, and suggest one reason may be variation in the aggressiveness of evaluations of thyroid tissue after thyroidectomy. However, they point out that rates were similar among the three institutions participating in this study, so a “more plausible explanation is that the overall incidence of thyroid cancer is increasing.”
The authors also emphasize that while 39% of the incidental cancers were larger than 1 cm and clinically relevant, they were missed despite current preop screening that included ubiquitous ultrasound and “liberal” use of fine-needle aspiration.
Dr. Solorzano and colleagues note that while Graves’ disease patients are best treated with total thyroidectomy, patients with nodular goiter can be successfully treated by lobectomy. However, in light of the current findings, “a total thyroidectomy in the hands of an experienced thyroid surgeon might be the best treatment for these patients.”
Still, given the retrospective nature of their study, “The authors suggest caution when recommending total thyroidectomy based solely on the incidental cancer rate data presented in this study. The natural history of these incidental cancers is most likely indolent, yet the complications of total thyroidectomy can be lifelong and substantial.”
SOURCE: Cancer after Thyroidectomy: A Multi-Institutional Experience with 1,523 Patients
J Am Coll Surg 2013.
