title: Risk of thyroid cancer based on thyroid ultrasound imaging characteristics: results of a population-based study.
abstract: OBJECTIVE
  There is wide variation in the management of thyroid nodules identified on ultrasound imaging.
  
  
  OBJECTIVE
  To quantify the risk of thyroid cancer associated with thyroid nodules based on ultrasound imaging characteristics.
  
  
  METHODS
  Retrospective case-control study of patients who underwent thyroid ultrasound imaging from January 1, 2000, through March 30, 2005. Thyroid cancers were identified through linkage with the California Cancer Registry.
  
  
  RESULTS
  A total of 8806 patients underwent 11,618 thyroid ultrasound examinations during the study period, including 105 subsequently diagnosed as having thyroid cancer. Thyroid nodules were common in patients diagnosed as having cancer (96.9%) and patients not diagnosed as having thyroid cancer (56.4%). Three ultrasound nodule characteristics--microcalcifications (odds ratio [OR], 8.1; 95% CI, 3.8-17.3), size greater than 2 cm (OR, 3.6; 95% CI, 1.7-7.6), and an entirely solid composition (OR, 4.0; 95% CI, 1.7-9.2)--were the only findings associated with the risk of thyroid cancer. If 1 characteristic is used as an indication for biopsy, most cases of thyroid cancer would be detected (sensitivity, 0.88; 95% CI, 0.80-0.94), with a high false-positive rate (0.44; 95% CI, 0.43-0.45) and a low positive likelihood ratio (2.0; 95% CI, 1.8-2.2), and 56 biopsies will be performed per cancer diagnosed. If 2 characteristics were required for biopsy, the sensitivity and false-positive rates would be lower (sensitivity, 0.52; 95% CI, 0.42-0.62; false-positive rate, 0.07; 95% CI, 0.07-0.08), the positive likelihood ratio would be higher (7.1; 95% CI, 6.2-8.2), and only 16 biopsies will be performed per cancer diagnosed. Compared with performing biopsy of all thyroid nodules larger than 5 mm, adoption of this more stringent rule requiring 2 abnormal nodule characteristics to prompt biopsy would reduce unnecessary biopsies by 90% while maintaining a low risk of cancer (5 per 1000 patients for whom biopsy is deferred).
  
  
  CONCLUSIONS
  Thyroid ultrasound imaging could be used to identify patients who have a low risk of cancer for whom biopsy could be deferred. On the basis of these results, these findings should be validated in a large prospective cohort.
authors: Department of Radiology and Biomedical Imaging, University of California, San Francisco2Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco3Department of Epidemiology and Biostatistics, University of California, San Francisco.
authors: Rebecca
authors: R
authors: Smith-Bindman
authors: Paulette
authors: P
authors: Lebda
authors: Vickie A
authors: VA
authors: Feldstein
authors: Dorra
authors: D
authors: Sellami
authors: Ruth B
authors: RB
authors: Goldstein
authors: Natasha
authors: N
authors: Brasic
authors: Chengshi
authors: C
authors: Jin
authors: John
authors: J
authors: Kornak
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012042:Registries; D012189:Retrospective Studies; D012306:Risk; D012680:Sensitivity and Specificity; D013961:Thyroid Gland / Q000000981:diagnostic imaging* / Q000473:pathology; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D016606:Thyroid Nodule / Q000000981:diagnostic imaging* / Q000473:pathology; D014463:Ultrasonography
references: Cancer. 1985 Aug 1;56(3):531-8
references: 2408737
references: Thyroid. 2007 Dec;17(12):1269-76
references: 17988196
references: Med Pediatr Oncol. 1998 Aug;31(2):91-5
references: 9680933
references: Eur J Endocrinol. 2008 Nov;159(5):493-505
references: 18728120
references: J Clin Endocrinol Metab. 2002 Nov;87(11):4924-7
references: 12414851
references: Arch Intern Med. 1994 Aug 22;154(16):1838-40
references: 8053752
references: Proc (Bayl Univ Med Cent). 2010 Jul;23(3):304-10
references: 21240322
references: Cancer Causes Control. 2008 Jun;19(5):515-25
references: 18270798
references: Diagn Cytopathol. 2008 Jun;36(6):390-9
references: 18478607
references: Endocrinol Nutr. 2010 Jun-Jul;57(6):240-4
references: 20447882
references: Clin Imaging. 2010 Mar-Apr;34(2):127-33
references: 20189077
references: Diagn Cytopathol. 2001 Oct;25(4):231-4
references: 11599106
references: Ann Intern Med. 2003 Jan 7;138(1):W1-12
references: 12513067
references: Semin Reprod Med. 2003 Feb;21(1):17-25
references: 12806556
references: Arch Intern Med. 2010 May 10;170(9):749-50
references: 20458080
references: Laryngoscope. 2010 Dec;120(12):2446-51
references: 21108428
references: QJM. 2007 Jan;100(1):29-35
references: 17178736
references: Thyroid. 2011 Feb;21(2):125-34
references: 21186939
references: Thyroid. 2004 Nov;14(11):953-8
references: 15671774
references: J Surg Res. 2011 Sep;170(1):96-9
references: 21550063
references: AJR Am J Roentgenol. 2009 Oct;193(4):1175-9
references: 19770344
references: JAMA. 2006 May 10;295(18):2164-7
references: 16684987
references: AJR Am J Roentgenol. 2010 Jan;194(1):31-7
references: 20028902
references: Eur Radiol. 2007 May;17(5):1358-64
references: 17021705
references: Ann Intern Med. 2005 Jun 7;142(11):926-31
references: 15941700
references: AJR Am J Roentgenol. 2002 Mar;178(3):687-91
references: 11856699
references: J Endocrinol Invest. 2010;33(5 Suppl):51-6
references: 20543551
references: Thyroid. 2006 Feb;16(2):109-42
references: 16420177
references: Radiology. 2008 Jun;247(3):762-70
references: 18403624
references: BMJ. 2012 May 28;344:e3502
references: 22645185
references: Thyroid. 2009 Nov;19(11):1167-214
references: 19860577
references: Clinics (Sao Paulo). 2012 Aug;67(8):945-54
references: 22948464
references: J Clin Endocrinol Metab. 2002 May;87(5):1941-6
references: 11994321
references: BMC Surg. 2009 Aug 10;9:12
references: 19664278
references: JAMA. 2012 Jun 13;307(22):2400-9
references: 22692172
references: Radiology. 2005 Dec;237(3):794-800
references: 16304103
references: Ann Intern Med. 1997 Feb 1;126(3):226-31
references: 9027275
references: Arch Otolaryngol Head Neck Surg. 2010 May;136(5):440-4
references: 20479371
references: JAMA. 1999 Sep 15;282(11):1061-6
references: 10493205