Prognostic impact of extrathyroid extension and clinical lymph node metastasis in papillary thyroid carcinoma depend on carcinoma size.
BACKGROUND
Although papillary thyroid carcinoma (PTC) generally has an indolent nature, massive extrathyroid extension (Ex) and clinical lateral node metastasis (N1b) are prominent predictors of a dire prognosis. However, it remains unknown whether these factors affect patient prognosis with uniformity. In this study, we investigated the relationships between the prognostic impact of these factors and carcinoma size.


METHODS
A total of 5,917 patients who underwent initial and curative surgery for PTC between 1987 and 1995 were enrolled in this study. After dividing these patients into four subsets based on tumor size--≦1.0 cm, 1.1-2.0 cm, 2.1-3.0 cm, and >3.0 cm--we investigated the prognostic impacts of Ex and N1b in each subset.


RESULTS
Relative risk (RR) of disease-free survival (DFS) of N1b was the highest in the subset ≦1.0 cm and decreased with tumor size. RR of Ex was smaller in carcinoma ≦3.0 cm but larger in carcinoma >3.0 cm compared with that of N1b in the respective subsets. On multivariate analysis, N1b was a more important prognostic factor than Ex in carcinoma ≦3.0 cm, but the prognostic impacts of these two factors were reversed in carcinoma >3.0 cm. Similar findings were obtained in analyses for cause-specific survival (CSS) and prognostic value of N1b was more significant in carcinoma ≦3.0 cm but less significant in carcinoma >3.0 cm than that of Ex.


CONCLUSIONS
The prognostic values of Ex and N1b vary with tumor size in PTC. It is important for physicians to pay attention to tumor size when evaluating the prognostic impact of these two prominent factors.
Fukushima
Mitsuhiro
M
Department of Surgery, Kuma Hospital, Kobe, Hyogo, Japan. mitch@hot.jp
Ito
Yasuhiro
Y
Hirokawa
Mitsuyoshi
M
Miya
Akihiro
A
Shimizu
Kazuo
K
Miyauchi
Akira
A
D000231:Adenocarcinoma, Papillary / Q000401:mortality / Q000473:pathology*; D000328:Adult; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D016019:Survival Analysis; D013964:Thyroid Neoplasms / Q000401:mortality / Q000473:pathology*
Cancer. 1991 Jul 15;68(2):324-30
2070332
J Surg Oncol. 1998 Aug;68(4):237-41
9721709
World J Surg. 2005 Jul;29(7):917-20
15951927
Cancer. 1985 Feb 15;55(4):805-28
3967175
Thyroid. 1995 Feb;5(1):25-8
7787429
World J Surg. 2006 May;30(5):780-6
16411013
Surgery. 1988 Dec;104(6):947-53
3194846
Endocr J. 1999 Feb;46(1):91-8
10426572
Endocr J. 2009;56(2):177-92
18703852
Int Surg. 1990 Oct-Dec;75(4):220-4
2292479
World J Surg. 2007 Apr;31(4):838-48
17347900
Med Klin (Munich). 1991 Feb 15;86(2):76-82
2030663
Surgery. 2004 Feb;135(2):139-48
14739848
Chirurg. 1996 Aug;67(8):788-806
8964151
Surgery. 1993 Dec;114(6):1050-7; discussion 1057-8
8256208
Br J Surg. 1995 Aug;82(8):1092-4
7648162
Virchows Arch A Pathol Anat Histol. 1982;396(1):19-39
7123844
Surg Today. 2006;36(1):12-8
16378187
World J Surg. 2007 Nov;31(11):2085-91
17885787
World J Surg. 2005 Apr;29(4):483-5
15776292
Eur J Surg. 1992 Nov-Dec;158(11-12):583-9
1363062
Cancer. 1997 Nov 1;80(9):1803-4
9351551
World J Surg. 1994 Jul-Aug;18(4):559-67; discussion 567-8
7725745
Am J Med. 1981 Mar;70(3):511-8
7211893