[Clinicopathologic implications of multifocal papillary thyroid carcinoma on poor prognostic outcomes: a propensity...

Objective: To analyze the clinicopathologic implications of multifocal thyroid papillary carcinoma on poor prognostic outcomes. Methods: The clinical data of 1 681 patients suffering thyroid papillary carcinoma (PTC) was collected between June 2014 and June 2018 at the Department of Thyroid Surgery, the First Affiliated Hospital of Zhengzhou University, including 1 299 female cases and 382 male cases, with a mean age of (44.4±11.5) years, ranging from 11 to 76 years. The male-to-female ratio was 1∶3.4. The relationship between multifocality and poor prognostic indicators was further retrospectively analyzed. Results: Patients with multifocal papillary thyroid carcinoma were older [(46.4±11.0) years vs (43.5±11.5) years, P<0.001] and had larger tumor diameter [0.8(0.5, 0.8) cm vs 0.7(0.5, 0.7) cm, P<0.001]. The tumors were much easier to have infiltrative tumor margin, extrathyroidal extension and lymph node metastasis with multifocality (all P<0.05). The propensity score matching method was further used to match the confounding factors. Bilateral multifocal thyroid cancer was an independent risk factor for extrathyroidal extension (OR=1.983, 95%CI: 1.379-2.852, P<0.001), central lymph node metastasis (OR=2.393, 95%CI: 1.797-3.187, P<0.001) and lateral lymph node metastasis(OR=3.327, 95%CI: 2.253-4.912, P<0.001). However, unilateral multifocal thyroid cancerhad no effect on the unfavorable prognostic indicators. Conclusions: Central compartment neck dissection is not recommended for unilateral multifocal thyroid cancer. However, we recommend central lymph node dissection for bilateral multifocality in PTC patients. If necessary, lateral compartment neck dissection is also supposed to be considered when lateral lymph node metastasis exists.