Lymph node status influences follow-up thyroglobulin levels in papillary thyroid cancer.
BACKGROUND
Elevated thyroglobulin (Tg) levels post surgery are associated with disease recurrence in papillary thyroid carcinoma (PTC). The aim of this study is to determine which clinicopathological factors influence Tg elevation following surgery and radio-iodine ablation (RAI) for PTC.


METHODS
A retrospective study of consecutive patients undergoing total thyroidectomy and RAI for PTC was carried out. Prophylactic central neck dissection (CND) was performed if the diagnosis of PTC was made preoperatively. Lateral neck dissection (LND) was guided by ultrasound findings. RAI was administered 6 weeks postoperatively. Stimulated Tg levels were measured at 12 months.


RESULTS
One hundred patients with PTC were studied. Forty patients had routine CND. The median tumour size was 15 mm. Median stimulated Tg level at 12 months was 0.3 mug/L. On multivariate analysis the number of metastatic lymph nodes removed had a significant positive association with serum Tg levels (P = 0.003). The total number of lymph nodes resected had a significant inverse relationship with serum Tg levels (P = 0.04). Tumour size, multifocality, vascular and capsular invasion did not appear to have significant correlation with Tg levels.


CONCLUSIONS
Lymph node metastases are associated with increased postablative Tg levels in PTC. More complete lymphadenectomy is associated with lowering of Tg levels.
Low
Tsu-Hui Hubert
TH
Department of Endocrine and Oncology Surgery, University Clinic, University of Sydney Endocrine Surgical Unit, Royal North Shore Hospital, St Leonards, NSW, 2065, Australia.
Delbridge
Leigh
L
Sidhu
Stan
S
Learoyd
Dianna
D
Robinson
Bruce
B
Roach
Paul
P
Sywak
Mark
M
D000328:Adult; D002291:Carcinoma, Papillary / Q000097:blood* / Q000000981:diagnostic imaging / Q000601:surgery; D017115:Catheter Ablation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008198:Lymph Nodes / Q000378:metabolism* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D015996:Survival Rate; D013954:Thyroglobulin / Q000097:blood*; D013964:Thyroid Neoplasms / Q000097:blood* / Q000000981:diagnostic imaging / Q000601:surgery; D013965:Thyroidectomy
D007457:Iodine Radioisotopes; D013954:Thyroglobulin