Endocrine Abstracts

Introduction:

• The incidence of primary hyperparathyroidism (PHPT) is ~3.5/100 000 per year
• The incidence is on the rise due to increase in ‘routine biochemical testing’
• Has been thought to be a ‘relatively harmless’ disorder.
• Some patients tend to undergo surgery, while others are conservatively treated and most followed up for a short period before discharge from follow up.

Aims:

• Determine if risk of cancer is increased in patients with primary hyperparathyroidism (PHPT)
• Determine if mortality is increased in patients with primary hyperparathyroidism.

Methodology:

• A cohort of patients with PHPT between 1981 and 2007 was identified from the Scottish morbidity records and linked to the Scottish cancer registry and Scottish mortality records.
• Patients with pre-existing cancers (or developing cancer within one year of diagnosis of PHPT) were excluded from the analysis of subsequent cancer risks.
• The prevalence of new cancers and deaths was identified in these patients.
• The results were then compared with the risk of cancer and mortality in the general population living in Scotland.

Outcome/results:

• Total number of patients diagnosed with PHPT: 3039
• Females: 2350 (77.3%), Males: 689 (22.7%)
• Mean age of patients: 63.5 years
• Person years at risk of cancer: 22 710
• New cases of cancer: 440/2706
• Standardised incidence rate of cancer: (SIR): 2.026, 95% CI (1.841–2.224), P<0.001
• Person years at risk of death: 24 186
• Number of deaths: 1601
• Standardised Incidence Rate of deaths: (SIR): 3.085, 95% CI (2.936–3.240) P<0.001

Conclusions:

• Individuals with PHPT have a two fold increased risk of developing subsequent cancer and a three fold increased risk of death as compared to general population.
• The findings of this study have enormous implications for management and follow up of patients diagnosed with primary hyperparathyroidism.