Download PDF
CC BY 4.0 · Surg J (N Y) 2021; 07(04): e307-e313
DOI: 10.1055/s-0041-1736669
Review Article

Risk Benefit Analysis of Routine Thymectomy for Differentiated Thyroid Cancers: A Systematic Review

Pallvi Kaul
1   Department of ENT and Head Neck Surgery, All India Institute of Medical Sciences, Rishikesh, Uttarakhand, India
,
Priyanka Kaul
2   Department of General Surgery, Government Medical College, Jammu, India
,
Dharma Ram Poonia 
3   Department of Surgical Oncology, All India Institute of Medical Sciences, Jodhpur, India
,
Ashish Jakhetiya
4   Department of Surgical Oncology, Geetanjali Medical College Hospital, Udaipur, Rajasthan, India
,
Vipin Arora 
5   Department of ENT and Head Neck Surgery, University College of Medical Sciences and Guru Teg Bahadur Hospital, University of Delhi, Delhi, India
,
Pankaj Kumar Garg 
6   Department of Surgical Oncology, Shri Guru Ram Rai Institute of Medical and Health Sciences, Dehradun, India
› Author Affiliations Funding Sources None.
› Further Information
Also available at
   Permissions and Reprints

Abstract

Background Central compartment lymph node dissection (CLND) is a part of the surgical management of differentiated thyroid cancer (DTC). Therapeutic CLND is done to address clinically significant central compartment nodes in patients with DTC, while prophylactic CLND is performed in the presence of high-risk features in the absence of clinically significant neck nodes. Removal of thymus—unilateral or bilateral—during CLND to achieve complete clearance of level VI and VII lymph node stations and address thymic metastasis is debatable.

Objective The present systematic review was conducted to summarize the evidence, delineating the role of thymectomy during CLND in patients with DTC.

Methods Electronic databases of PubMed, Embase, and Cochrane were searched from their inception to July 2020 using keywords—thyroid neoplasms or tumors, thyroidectomy, and thymectomy—to identify the articles describing the role of thymectomy during CLND in DTC. A pooled analysis of surgicopathological outcomes was performed using metaprop command in STATA software version 16.

Result A total of three studies and 347 patients—total thyroidectomy (TT) with bilateral thymectomy in 154, TT with unilateral thymectomy in 166, and TT alone in 27 patients with DTC—were included in the systematic review. The pooled frequency of thymic metastasis was a mere 2% in patients undergoing either unilateral or bilateral thymectomy. The routine addition of thymectomy does not result in better lymph node clearance. Unilateral and bilateral thymectomy were associated with high chances of transient hypocalcemia (12.0% and 56.1%, respectively).

Conclusion Routine thymectomy is not warranted during CLND, considering minimal oncological benefit and high risk of postoperative hypocalcemia.

Keywords

Head And Neck Cancer - Thyroid neoplasms - Central compartment node dissection - Thyroidectomy - Thymectomy

Statement of Ethics

All analyses were based on previously published studies. Ethical approval and patient consent forms were not required.


Author Contributions

All authors participated in the study's conceptualization. P.K., P.K.G., and A.J. participated in data collection. P.K., P.K.G., D.P., and V.A. participated in data analysis. All authors participated in writing the original draft; All authors wrote, reviewed, edited, and approved this final manuscript.


Disclosure Statement

The authors have no conflicts of interest to declare.




Publication History

Received: 08 December 2020

Accepted: 25 August 2021

Article published online:
15 December 2021

© 2021. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)

Thieme Medical Publishers, Inc.
333 Seventh Avenue, 18th Floor, New York, NY 10001, USA

 

  • References

  • 1 Bray F, Ferlay J, Soerjomataram I, Siegel RL, Torre LA, Jemal A. Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin 2018; 68 (06) 394-424
    CrossrefPubMedGoogle Scholar
  • 2 Haugen BR, Sawka AM, Alexander EK, Bible K, Caturegli P, Doherty G. The ATA guidelines on management of thyroid nodules and differentiated thyroid cancer task force review and recommendation on the proposed renaming of eFVPTC without invasion to NIFTP. Thyroid 2017; 27: 481-483
    CrossrefPubMedGoogle Scholar
  • 3 Haugen BR, Alexander EK, Bible KC. et al. 2015 American Thyroid Association management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer: the American Thyroid Association guidelines task force on thyroid nodules and differentiated thyroid cancer. Thyroid 2016; 26 (01) 1-133
    CrossrefPubMedGoogle Scholar
  • 4 Carty SE, Cooper DS, Doherty GM. et al; American Thyroid Association Surgery Working Group, American Association of Endocrine Surgeons, American Academy of Otolaryngology-Head and Neck Surgery, American Head and Neck Society. Consensus statement on the terminology and classification of central neck dissection for thyroid cancer. Thyroid 2009; 19 (11) 1153-1158
    CrossrefPubMedGoogle Scholar
  • 5 Boyd JD. Development of the thyroid and parathyroid glands and the thymus. Ann R Coll Surg Engl 1950; 7 (06) 455-471
    PubMedGoogle Scholar
  • 6 El Khatib Z, Lamblin J, Aubert S. et al. Is thymectomy worthwhile in central lymph node dissection for differentiated thyroid cancer?. World J Surg 2010; 34 (06) 1181-1186
    CrossrefPubMedGoogle Scholar
  • 7 Huang D-P, Ye X-H, Xiang Y-Q, Zhang X-H. Thymectomy in central lymph node dissection for papillary thyroid cancer. Int J Clin Exp Med 2014; 7 (04) 1135-1139
    PubMedGoogle Scholar
  • 8 Li W, Wang B, Jiang ZG, Feng YJ, Zhang W, Qiu M. The role of thymus preservation in parathyroid gland function and surgical completeness after bilateral central lymph node dissection for papillary thyroid cancer: A randomized controlled study. Int J Surg 2019; 65: 1-6
    CrossrefPubMedGoogle Scholar
  • 9 Kendall MD. Functional anatomy of the thymic microenvironment. J Anat 1991; 177: 1-29
    PubMedGoogle Scholar
  • 10 Costa NS, Laor T, Donnelly LF. Superior cervical extension of the thymus: a normal finding that should not be mistaken for a mass. Radiology 2010; 256 (01) 238-242
    CrossrefPubMedGoogle Scholar
  • 11 Lin YS, Hsueh C, Wu HY, Yu MC, Chao TC. Incidental parathyroidectomy during thyroidectomy increases the risk of postoperative hypocalcemia. Laryngoscope 2017; 127 (09) 2194-2200
    CrossrefPubMedGoogle Scholar
  • 12 Lorente-Poch L, Sancho JJ, Ruiz S, Sitges-Serra A. Importance of in situ preservation of parathyroid glands during total thyroidectomy. Br J Surg 2015; 102 (04) 359-367
    CrossrefPubMedGoogle Scholar
  • 13 Hermann M, Ott J, Promberger R, Kober F, Karik M, Freissmuth M. Kinetics of serum parathyroid hormone during and after thyroid surgery. Br J Surg 2008; 95 (12) 1480-1487
    CrossrefPubMedGoogle Scholar
  • 14 Del Rio P, Rossini M, Montana CM. et al. Postoperative hypocalcemia: analysis of factors influencing early hypocalcemia development following thyroid surgery. BMC Surg 2019; 18 (Suppl. 01) 25
    CrossrefPubMedGoogle Scholar
  • 15 Goswami S, Peipert BJ, Mongelli MN. et al. Clinical factors associated with worse quality-of-life scores in United States thyroid cancer survivors. Surgery 2019; 166 (01) 69-74
    CrossrefPubMedGoogle Scholar
  • 16 Barczyński M, Konturek A, Stopa M, Nowak W. Prophylactic central neck dissection for papillary thyroid cancer. Br J Surg 2013; 100 (03) 410-418
    CrossrefPubMedGoogle Scholar
  • 17 Popadich A, Levin O, Lee JC. et al. A multicenter cohort study of total thyroidectomy and routine central lymph node dissection for cN0 papillary thyroid cancer. Surgery 2011; 150 (06) 1048-1057
    CrossrefPubMedGoogle Scholar
  • 18 Hartl DM, Mamelle E, Borget I, Leboulleux S, Mirghani H, Schlumberger M. Influence of prophylactic neck dissection on rate of retreatment for papillary thyroid carcinoma. World J Surg 2013; 37 (08) 1951-1958
    CrossrefPubMedGoogle Scholar
  • 19 Sywak M, Cornford L, Roach P, Stalberg P, Sidhu S, Delbridge L. Routine ipsilateral level VI lymphadenectomy reduces postoperative thyroglobulin levels in papillary thyroid cancer. Surgery 2006; 140 (06) 1000-1005 , discussion 1005–1007
    CrossrefPubMedGoogle Scholar