Is active monitoring enough?

There are some centers that advocate pursuing a strategy of active surveillance without surgery for small papillary thyroid carcinomas (PTC), which are increasingly encountered in clinical practice. A population-based cohort study has now examined how many and which patients die from small PTC in the first place. This can be used to define at-risk patients for whom active observation could be dangerous.

Specifically, the study [1] aimed to determine the disease-specific mortality of PTCs with a maximum extension of ≤2 cm.

A US registry from 1988-2007 (61 523 patients) served as the data basis. The characteristics of deceased patients with such tumor size and the influence of clinical procedures on patient survival were examined.

Which characteristics play a role?

Throughout the 20-year study period, the thyroid cancer-associated mortality rate was 2.8% (1753 patients). What about the small PTCs?
Of those who died, 38% had PTC, 10% had follicular, and 31.3% had anaplastic thyroid carcinoma.
Of those who died, 12.3% had a PTC of the size described above (≤2 cm). They all died even though they had undergone thyroidectomy. These cases were significantly more likely to be men (30 vs. 17%), ≥45 years old (92 vs. 52%), have tumor size greater than one centimeter (59 vs. 46%), extrathyroidal spread (41 vs. 11%), lymph node (77 vs. 28%), and distant metastases (31 vs. 1%) compared with individuals with small PTC who were still alive. This can be used to characterize a risk population that is very unlikely to be suitable for a nonoperative approach.
Of these characteristics, age (≥45 years), metastases, extrathyroidal spread, and just remarkably, procedures that were less than lobectomy of the thyroid gland in extent were independent risk factors for death.

Caution is advised

Because of the relatively high death rate even of operated PTC patients, the authors conclude that nonoperative management of small PTCs should be used cautiously-especially in men who have exceeded an age of 45 years. These require at least one lobectomy of the thyroid gland.

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