Thyroid Debate (Papillary Thyroid Cancer: Extent of Thyroidectomy)

1
Thyroid Debate (Papillary Thyroid Cancer Extent
of Thyroidectomy)

• 30 Aug 2007
• Surgery-OMMC

JGGuerra, MD HCruz, MD
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Papillary Thyroid Cancer Controversies in
treatment

• Surgical resection is the key to management of
  thyroid cancer, but determining the optimal
  surgical procedure for individual cases has been
  controversial.

3

• A prospective, randomized study of total vs less
  than total thyroidectomy is impossible
• due to the excellent outcome in the low-risk
  group
• the requirement of long-term follow-up
• large number of patients needed to show any
  statistical difference in long-term survival
  outcome.

4

• Management protocols for WDTC are based on
  retrospective data on prognostic indicators
  (patient risk and tumor risk factors)
• Clinicians rely on large patient cohort studies
  in which therapy has not been randomized, leading
  to some disagreement about management

5

• It is timely to discuss whether total
  thyroidectomy is a better treatment option
  compared to subtotal thyroidectomy for a 45F with
  2 cm papillary thyroid cancer

6
Premise

• Is total thyroidectomy a rational treatment of
  choice for a 45F with 2cm papillary thyroid
  cancer?
• YES

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Arguments

1. 30-87.5 of papillary carcinomas involve
   opposite lobe (Hirabayashi, 1961, Russell, 1983)
2. 10-20 develop recurrence in the contralateral
   lobe (Soh, 1996)
3. Lower recurrence rates, some studies show
   increased survival (Mazzaferri, 1991)
4. Facilitates earlier detection and tx for
   recurrent or metastatic carcinoma with RAI (Soh,
   1996)
5. Residual WDTC has the potential to
   dedifferentiate to ATC

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Literature Review
9
Databank Total Thyroidectomy

• Analysis of surgical procedures performed in over
  1500 United States hospitals reveals that among
  5584 patients with thyroid cancer the majority
  (77.4) underwent total thyroidectomy regardless
  of tumor histology and stage (Mazzafferi)

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Recurrence rates with lobectomy

• Performing lobectomy alone may result in a 510
  recurrence rate in the opposite thyroid lobe
  (4,1), a high tumor recurrence rate, and a high
  (11) incidence of subsequent pulmonary
  metastases.

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Multicentricity

• The fact that local recurrence signifies a
  substantial risk of subsequent tumour-related
  mortality is emphasized by several workers
• Total thyroidectomy eliminates the multicentric
  microscopic foci present in up to 85 of
  papillary carcinomas6,12 as potential sites of
  local recurrence, or the anaplastic
  transformation that occurs in 13

12

• Patients undergoing lobectomy have a recurrence
  rate in the contralateral lobe of 5 to 25, with
  a mean of 7, and up to one- half of these
  patients eventually die of thyroid cancer, some
  of whom were initially considered low risk.5

13
Cancer mortality rates with lobectomy

• Hay et al. reported that patients treated for
  low-risk papillary cancers Age, Grade, Extent,
  Size (AGES) score 3.99 had no improvement in
  survival rates after undergoing more than
  lobectomy.
• Later, they reported the results of a study
  designed to compare outcomes after unilateral or
  bilateral lobectomy for papillary cancer
  considered to be low risk by AMES criteria.

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• Although there were no significant differences in
  cancer-specific mortality or distant metastasis
  rates between the two groups, the 20-yr rates for
  local recurrence and nodal metastasis after
  unilateral lobectomy were 14 and 19,
  respectively, significantly higher (P 0.0001)
  than the 2 and 6 rates, respectively, seen
  after bilateral thyroid resection

15

• Hay et al. (30) concluded that bilateral thyroid
  resection is the preferable initial surgical
  approach to patients with low-risk papillary
  cancer

16

• Tollefsen et al reported a 5.7 local recurrence
  rate in the contralateral thyroid remnant, and
  41 of these patients died.

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Management Options
BENEFIT BENEFIT BENEFIT RISK for Complication COST AVAILABILITY
Total Thyroidectomy Muticentricity RR Survival Rate 1-3 RLN injury /
Total Thyroidectomy lt5 1-3 RLN injury /
Subtotal Thyroidectomy 10-15 lt1 /
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Summary

• Retrospective data showed favorable result for
  total thyroidectomy in terms of
• low recurrence rate in the ipsilateral lobe
• prevention of development of cancer on the
  contralateral lobe
• acceptable morbidity
• facilitation of post operative treatment

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Thank You
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References

1. Clark OH. Total thyroidectomy the treatment of
   choice for patients with differentiated thyroid
   cancer. Ann Surg 1982 196 36170
2. Hay ID, Grant CS, Taylor WF, McConahey WM.
   Ipsilateral lobectomy versus bilateral lobar
   resection in papillary thyroid carcinoma a
   retrospective analysis of surgical outcome using
   a novel prognostic scoring system. Surgery 1987
   102 108895.
3. Grant CS, Hay ID, Gough IR, Bergitralb EL,
   Goellner JR, McConahey WM. Local recurrence in
   papillary thyroid carcinoma is the extent of
   surgical resection important? Surgery 1988 104
   95462
4. Mazzaferri EL, Young RL. Papillary thyroid
   carcinoma a 10-year follow-up report of the
   impact of treatment in 576 patients. Am J Med
   1981 70 5118.

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• 5. McConahey WM, Hay ID, Woolner LB, van Heerden
  JA, Taylor WE. Papillary thyroid cancer treated
  at the Mayo Clinic, 1946 through 1970initial
  manifestations, pathologic findings, therapy and
  outcome. Mayo Clin Proc 1986 6 97896.
• 6. Rossi RL, Cady B, Silverman, ML, Wool MS,
  Homer TA. Current results of conservative surgery
  for differentiated thyroid carcinoma. World JSurg
  1986 10 61222.
• 7. Shah JP, Loree TR, Dharker D, Strong EW.
  Lobectomy versus total thyroidectomy for
  differentiated carcinoma of the thyroid a
  marched-pair analysis. AmJSurg 1993 1663315.
• 8. Tollefsen HR, Shah, JP, Huvos AG. Papillary
  carcinoma of the thyroid. Recurrence in the gland
  after initial surgical treatment. AmJSurg
  1972124 46872.