1. Management of Papillary Ca Thyroid
JHSGR
Management of Papillary Ca Thyroid
Chris Cheng Tsz Ling
Princess Margaret Hospital

2. Introduction
Thyroid carcinoma has the fastest rising incidence of all major cancers, ↑4% per year
Papillary thyroid carcinoma(PTC) is the most common type of differentiated thyroid carcinoma, incidence x 2 throughout 25 years
Excellent prognosis, 10-year cancer specific survival rate >90%
Locoregional recurrence (LRR) is a major cause of disease morbidity
Grubbs EG, Rich TA, Li G, et al. Recent advances in thyroid cancer. Curr Probl Surg 2008;45:156 –250
Cancer incidence and mortality in Hong Kong 1983–2008: Hong Kong Cancer Registry, Hong Kong
ADD HK INCIDENCE OF THRYOID CANCER AND PAPILLARY THYROID CANCER

3. Agenda The optimal extent of surgery
Prophylactic central neck LN dissection
Rationale for use of adjuvant radioactive iodine (RAI) remnant ablation
Agenda

4. Thyroidectomy

5. Total/Near total Thyroidectomy Vs Lobectomy
Total thyroidectomy (n=43227) Vs Lobectomy (n=8946)
≥ 1cm CA thyroid, Lobectomy was associated with
15% higher risk of recurrence (p=0.04)
31% higher risk of death (p=0.009)
< 1cm CA thyroid, no difference in recurrence or survival
Bilimoria et al. Extent of surgery affects survival for papillary thyroid cancer. Ann Surg 2007 Sep;246(3):375-81
American Thyroid Association recommendation:
Lobectomy: for <1cm, low risk, unifocal, intrathyroidal papillary carcinoma without cervical LN or history of head & neck irradiation
Near-total / Total thyroidectomy: for >1cm

6. Neck LN Dissection

7. Neck Dissection Therapeutic
- Clinically evident and biopsy proven LN involvement
Prophylactic
No clinical evidence of LN
HOT debate: Prophylactic Central LN dissection(level VI)
Neck Dissection

8. Central neck dissection (minimum) Pre-laryngeal Pre-tracheal
Para-tracheal
Central neck dissection may be extended to:
Retropharyngeal
Retroesophageal
Paralaryngopharyngeal (superior vascular pedicle)
Superior mediastinal (inferior to innominate artery)
ATA Guideline. Consensus Statement on the Terminology and Classification
of Central Neck Dissection for Thyroid Cancer. Thyroid. Volume 19, Number 11, 2009

9. Central Neck dissection
SEER (Surveillance, Epidemiology, and End Results) database
9904 Papillary thyroid cancer
Cervical LN met in papillary cancer of Age>45
Independent risk factor for decreased survival
The most common site for lymph node metastases and DTC recurrence is within the central compartment
Roh JL et al. Total thyroidectomy plus neck dissection in differentiated papillary thyroid carcinoma patients: pattern of nodal metastasis, morbidity, recurrence, and postoperative levels of serum parathyroid hormone. Ann Surg :604–610.
Central neck dissection may convert some patients from cN0 to pathologic N1a

10. Central Neck dissection
Mayo clinic 60-year observation in 900 patients with <1cm microcarcinoma
In 450 patients with any form of LN surgery done,
30% lymph node involvement at initial surgery
80% recurrence at central LN
Hay ID et al. Papillary thyroid microcarcinoma: a study of 900 cases observed in a 60-year period. Surgery :980–987.

11. CND may reduce recurrence
In 950 Papillary thyroid cancer patients
Stage I 45%, Stage II 25%, Stage III 22%, Stage IV 6%
75% LN dissection done (mostly CND only)
Recurrences
LN dissection: 6.8%
No LN dissection: 16.5% (p<0.001)
Stage I (1%), Stage II (6%), Stage III (6%), Stage IV (77%)
No difference in 10-yr / 15-yr survival
Toniato A et al. Papillary thyroid carcinoma: factors influencing recurrence and survival. Ann Surg Oncol 2008;15: 1518–1522.

12. Central Neck Dissection
Seems Improve survival in comparing observational studies
Tisell LE et al. Improved survival of patients with papillary thyroid cancer after surgical microdissection. World J Surg :854–859.

13. Central Neck Dissection
Increases the proportion of patients who appear disease free with unmeasureable Tg levels 6 months after surgery
undetectable TG levels
Total thyroidectomy + CND: 72%
Total thyroidectomy only: 43% (p<0.001)
Sywak M et al. Routine ipsilateral level VI lymphadenectomy reduces postoperative thyroglobulin levels in papillary thyroid cancer. Surgery :1000–1007

14. Central neck dissection increases complications?

15. Complications of thyroidectomy alone Vs thyroidectomy + CND
Chrisholm et al. Systematic review and meta-analysis of the adverse effects of thyroidectomy combined with central neck dissection as compared with thyroidectomy alone. Laryngoscope 2009 Jun;119(6):1135-9

16. Complications of thryoidectomy alone Vs thryoidectomy + CND
Chrisholm et al. Systematic review and meta-analysis of the adverse effects of thyroidectomy combined with central neck dissection as compared with thyroidectomy alone. Laryngoscope 2009 Jun;119(6):1135-9

17. Central Neck Dissection
All existing literatures are cohort studies
No RCT
American thyroid association has commented it is NOT feasible to do an RCT on prophylactic central neck dissection
Need to randomize 5840 patients to have enough power to show a difference in recurrence or complications!
American Thyroid Association Design and Feasibility of a Prospective Randomized Controlled Trial of Prophylactic Central Lymph Node Dissection for Papillary Thyroid Carcinoma. THYROID. Volume 22, Number 3, 2012

18. Central Neck Dissection
Pros
↓ recurrence
Lower postop serumTg
- To simplify FU and surveillance for recurrence
3)↓ need for reoperation in the central neck
Cons
↑ temporary hypoparathyroidism (1- 4%)
↑temporary RLN injury(2-12%)

19. American Thyroid Association (ATA) guideline – Central neck dissection
Prophylactic central-compartment neck dissection (ipsilateral or bilateral)
PTC with clinically uninvolved central neck LN,
especially for advanced primary tumors (T3 or T4).
Recommendation rating: C
Near-total or total thyroidectomy without prophylactic central neck dissection
for small (T1 or T2), noninvasive, clinically node-negative PTCs.
These recommendations should be interpreted in light of available surgical expertise.

20. Radioactive Iodine Ablation

21. Role of post thyroidectomy RAI
Remnant ablation (to facilitate detection of recurrent disease and initial staging)
Adjuvant therapy (to decrease risk of recurrence and disease specific mortality by destroying suspected, but unproven metastatic disease), or
RAI therapy (to treat known persistent disease).

22. ↓ Recurrence and cancer death in Stage 2/3 disease
Mazzaferri EL, Jhiang SM 1994 Long-term impact of initial surgical and medical therapy on papillary and follicular thyroid cancer. Am J Med 97:418–428.

23. RAI improved survival The single most powerful prognostic indicator
↑ increase disease-free interval (p<0.001)
↑ increase survival
Samaan Na et al. The results of various modalities of treatment of well differentiated thyroid carcinomas: a retrospective review of 1599 patients. J Clin Endocrinol Metab :714–720.

24. The National Thyroid Cancer Treatment Cooperative Study Group (NTCTCSG)
2936 patients
median follow-up of 3 years
Near-total thyroidectomy followed by RAI therapy and aggressive thyroid hormone suppression therapy
Improved overall survival of patients with NTCTCSG stage II-IV disease
No impact of therapy in stage I disease
Jonklaas J et al. Outcomes of patients with differentiated thyroid carcinoma
following initial therapy. Thyroid :1229–1242.

25. Mayo Clinic experience on MACIS low risk papillary thyroid cancer
Hay ID, McConahey WM, Goellner JR. Managing patients with papillary thyroid carcinoma: insights gained from the Mayo Clinic’s experience of treating 2,512 consecutive patients during 1940 through Trans Am Clin Climatol Assoc :241–260

26. RAI in papillary thyroid microcarcinoma
RAI after thyroidectomy for <1cm PTM did not reduce recurrence
Hay ID et al. Papillary thyroid microcarcinoma: a study of 900 cases observed in a 60-year period. Surgery :980–987.

27. RAI in papillary cancer
RAI did not show benefit in low risk disease
Recurrence and survival benefits restricted to:
>1.5cm
Residual disease following surgery

28. ATA guideline on RAI remnant ablation
SELECTIVE USE

29. ATA guideline on RAI remnant ablation
Recommended for T3-4 or M1
Recommended for selected cases in 1-4cm thyroid cancers with:
Lymph node metastases, or
high risk features
Age >45, tumor invasion, individual histology, incomplete resection
Recommendation rating: C
NOT recommended for patients with:
unifocal cancer <1 cm without other higher risk features
Recommendation rating: E
multifocal cancer when all foci are <1 cm in the absence other higher risk features

30. Conclusion Individualized management according to risk stratification
Low Vs High risk
Total/Near-total Thyroidectomy is standard for >1cm papillary thyroid cancer
Prophylactic Central neck dissection is indicated for T3-4 tumors to reduce local recurrence
For T1-2 tumors, need to balance benefits and complications
RAI mainly indicated for T3-4 & M1 disease

31. Thank you