Outcome after thyroid surgery for metastasis from renal cell cancer

Owing to their rarity, the prognostic ramifications of thyroid metastases from renal cell cancer are unclear.

This retrospective analysis comprised 17 patients who underwent thyroid surgery (15 total thyroidectomies, 2 lobectomies) for renal cell cancer metastases.

The mean follow-up after thyroid surgery was 65 months. Seven of the 9 deaths involved patients with extrathyroidal metastatic growth despite previous locally curative resection in all but 1 patient. There was a strong relationship between extrathyroidal growth and recurrent laryngeal nerve invasion (57 vs 0%; P=.015), cervical lymph node metastasis (71 vs 0%; P=.003), the number of positive neck nodes (means of 1 vs 0 nodes; P=.014), laryngeal, tracheal or esophageal invasion (43 vs 0%; P=.05), and internal jugular vein invasion (43 vs 0%; P=.05). Powerful effects on cause-specific mortality after thyroid operation for renal cell cancer metastases were seen for extrathyroidal growth (means of 15 vs 69 months; P=.004) and recurrent laryngeal nerve invasion (means of 10 vs 56 months; P=.002).

Extrathyroidal metastatic growth reflects an aggressive tumor biology, which may extend to other renal cell cancer metastases outside the neck. In this setting, extensive surgery aimed at preventing local complications should be embedded in a systemic treatment concept.