title: Risk factor analysis for central nodal metastasis in papillary thyroid carcinoma.
abstract: Lymph node involvement is associated with recurrence in papillary thyroid carcinoma (PTC). The central neck compartment (level VI) lymph nodes are at the greatest risk of metastases from PTC, but the role of central neck dissection (CND) remains controversial, particularly in PTC without clinical cervical lymph node metastasis (cN0). The present study aimed to identify risk factors of central cervical nodal metastasis and the safety of CND in patients with cN0PTC. The current study retrospectively investigated 389 patients who had been followed up for 12.0-25.5 months after surgery, and were divided into positive or negative lymph node involvement groups according to the pathological results subsequent to this surgery. Univariate and multivariate analyses were used to study the risk factor of central node involvement. The mean tumor size was 0.71±0.35 cm (range, 0.1-2.0 cm). There was no significant difference in the rate of central lymph node involvement based on age (<45 or ≥45 years) or tumor focality (unifocal or multifocal). However, there were significant differences based on gender, extra-thyroid invasion and tumor size (P<0.05). The incidence of transient hypoparathyroidism and transient vocal cord paralysis following CND was 12.34 and 4.11%, respectively. No patient experienced permanent hypoparathyroidism or vocal cord paralysis. One patient (1/389; 0.23%) experienced disease recurrence during the follow-up. A larger tumor size and the male gender were significantly associated with the central nodal metastasis rate for cN0PTC with a tumor size of <2.0 cm. CND for cN0PTC patients was safe and the tumor-associated recurrence rate following CND plus total thyroidectomy was low. The present study suggests that CND should be conducted for male cN0PTC patients with a larger tumor size (≥0.5 cm).
authors.affiliation: International Health Care Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China.
authors.forename: Ling-Na
authors.initials: LN
authors.lastname: Mao
authors.affiliation: Department of General Surgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China.
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of General Surgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China.
authors.forename: Zhi-Yu
authors.initials: ZY
authors.lastname: Li
authors.affiliation: Department of General Surgery, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: International Health Care Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China.
authors.forename: Zheng-Ya
authors.initials: ZY
authors.lastname: Song
keywords: central neck dissection; hypoparathyroidism; papillary thyroid carcinoma; total thyroidectomy; vocal cord paralysis