Occurrence of malignant neoplasia in patients with primary hyperparathyroidism

Introduction: The association between primary hyperparathyroidism (1HPT) and cancer is debated. The present study was aimed to investigate the occurrence of neoplasia in 1HPT. Patients and methods: All consecutive patients (n = 1750) referred to our "Osteoporosis and Metabolic Disease" outpatients clinic for osteoporosis or hypercalcemia were eligible for the study. The exclusion criteria were: the finding of osteoporosis and/or altered calcium-phosphorous metabolism in the context of investigations for malignancy, the presence of diseases known to influence the cancer risk and the heavy smoking habit. Eventually, 1606 patients (1407 females, 199 males) were enrolled. In all patients calcium-phosphorous metabolism, PTH and vitamin D levels were measured and the occurrence of cancer during the 10. years prior the study inclusion was recorded. Results: One-hundred-sixty-three patients had 1HPT while 1443 had not. Patients with and without 1HPT were comparable for age and gender. In 1HPT patients the occurrence of all, breast, kidney and skin cancer was significantly higher (21.5%, 12.2%, 2.5%, 1.8%, respectively) than in patients without 1HPT (12.4%, 6.9%, 0.3%, 0.3%, p. <. 0.05 for all comparisons). The 1HPT presence was significantly associated with the occurrence of all neoplasia and of breast, skin and kidney neoplasia (odds ratio, 95% confidence interval, p value: 1.93, 1.27-2.92, 0.002; 1.93, 1.11-3.35, 0.002; 9.18, 2.16-38.8, 0.003; 8.23, 1.71-39.5, 0.008, respectively), after adjusting for age, gender (as appropriate), smoking habit and vitamin D levels. Conclusion: During the 10. years prior the diagnosis of 1HPT, the occurrence of all, breast, skin and kidney neoplasia is increased.