Parathyroidectomy in Mild Asymptomatic Primary Hyperparathyroidism

1
Parathyroidectomy in Mild Asymptomatic Primary
Hyperparathyroidism

• POW Journal Club
• 7 July 2003
• Camille Wu

2
Clinical Question

• Symptomatic parathyroid disease with significant
  hypercalcaemia
• Vs
• Asymptomatic parathyroid disease with mild
  hypercalcaemia
• Role of parathyroidectomy

3
Search History

• Hyperparathyroidism or primary hyperthyroidism or
  Hypercalcaemia
• Parathyroidectomy or surgery
• 1 and 2 limit to RCT

4
Paper identified

• Randomized trial of parathyroidectomy in mild
  asymptomatic primary hyperparathyroidism Patient
  description and effects on the SF-36 health
  survey
• Gary Talpos, Henry G Bone III, Michael
  Kleerekoper, et al
• Surgery, 1281013-21, Dec 2000

5
Method - recruitment

• Patients referred to Henry Ford Hospital April
  1994 March 1997
• Eligibility and Exclusion criteria applied
• Baseline history, examination and investigations
  and SF-36 Health Survey
• Repeated every 6 months

6
SF-36 Health Survey

• Physical functioning
• Social functioning
• Role functioning physical
• Role functioning emotional
• Mental health
• Vitality
• Body pain
• General health perception
• Health Change

7
Method arms of study

• Block randomisation into operative or
  non-operative (observation) groups
• Operative group
• Operation within 4 weeks of randomisation
• Single surgeon
• Standard parathyroidectomy bilateral approach
• Removal of all enlarged glands

8
Method - analysis

• Baseline laboratory and medical history variables
• Univariate analyses

9
Method - analysis

• Tabulation of results
• Success of outcome
• Incidence of persistent disease
• Incidence of resistant disease
• Number and weight of involved glands
• Complications of surgery
• Non-operative group patients requiring surgery
  for new symptoms
• Change over time measures on SF-36

10
Results

• 53 patients
• 25 operative group (2 refused op)
• 28 non-operative group (3 later required
  operations)
• Female preponderence (42F 11M)
• Both groups balanced
• Op group older than non-op (66.7 vs 62.6)
• Follow-up rate 100

11
Results and Discussion

• Multigland disease in 6/26 (23)
• Weight of glands
• range 0.080g to 9.58g
• No post-operative complications

12
Results and Discussion

• No persistent hypercalcaemia or raised PTH levels
  post-op and for gt 1 year
• Despite multigland disease
• Normalisation of Ca2 and PTH levels ascribed to
  bilateral approach

13
Results and Discussion

• Recurrence of hyperparathyroidism in 2/26
  operated patients at slightly over one year
  post-op
• Attributed to high rate of multigland disease
• Unknown if recurrence rate will increase with
  time

14
Results and Discussion

• Number of non-operative patients developing
  symptoms and requiring operation is 3/28 (11)
• Reflects nature of disease?
• Or bias due to close monitoring?

15
Results

• SF-36 favoured operative group on 2 scales
• Social functioning plt0.07
• Role functioning (emotional) plt0.12
• ? Detects patients at preclinical stage before
  physical changes occur and symptoms develop

16
Conclusion of study

• First RCT displaying significant improvement in
  SF-36 result
• Supports parathyroidectomy soon after diagnosis
  of primary hyperparathyroidism
• Ethical problem with sham surgery comparison
  group
• Further studies

17
Critical Appraisal

• Randomised controlled trial
• Not blinded - possible placebo effect
• ? block randomisation
• Study population all within 100 mile radius of
  downtown Detroit relevance to local population
• Intention to treat analysis
• 100 follow-up

18
Critical Appraisal

• SF-36 Survey
• Subjective? But tested
• Statistical significance translating to clinical
  significance
• 2/9 domains improved - ? significance
• 6/9 domains worse but not statistically
  significant