Long-Term Outcomes After Lobectomy for Patients with High-Risk Papillary Thyroid Carcinoma

Guidelines universally recommend total thyroidectomy for high-risk papillary thyroid carcinoma (PTC). However, in Japan, thyroid-conserving surgery had been widely applied for such patients until recently. We investigated long-term outcomes for this strategy.

A prospectively recorded database was retrospectively analyzed for 368 patients who had undergone curative surgery for high-risk PTC without distant metastasis between 1993 and 2013. High-risk PTC was defined for tumors showing tumor size > 4 cm, extrathyroidal extension, or large nodal metastasis ≥ 3 cm.

Median age was 59 years and 243 patients were female. Mean duration of follow-up was 12.7 years. Lobectomy was conducted for 207 patients (LT group) and total or near-total thyroidectomy for 161 patients (TT group). The frequency of massive extrathyroidal invasion and large nodal metastasis was lower in the LT group than in the TT group. After propensity score matching, no significant differences were seen between groups for overall survival, cause-specific survival or distant recurrence-free survival. In the overall cohort, multivariate analysis identified age ≥ 55 years, large nodal metastasis, tumor size > 4 cm and massive extrathyroidal invasion as significantly associated with cause-specific survival, whereas extent of thyroidectomy was not.

For patients with high-risk PTC without distant metastasis, curative surgery with lobectomy showed almost identical oncological outcomes compared to total thyroidectomy. The benefits of total thyroidectomy for high-risk PTC should be reevaluated in the future prospective studies.