R. Arrangoiz1, D. Margain1, D. Margain1, J. Sanchez1, F. Cordera1, D. Caba1, M. Muñoz1, E. Moreno1, E. Luque1, R. Arrangoiz1 1Sociedad Quirúrgica S.C. at the American British Cowdray Medical Center,Surgical Oncology / Head And Neck Surgery / Endocrine Surgery,Mexico City, MEXICO CITY, Mexico
Introduction: Breast cancer is the leading malignancy in women and the second leading cause of cancer-related deaths across the world. Hypercalcemia is known to occur in up to 20% to 30% of the patients with cancer at some point during the course of their illness. Breast cancer is one of the malignancies most commonly associated with hypercalcemia. Primary hyperparathyroidism (PHPT) has been associated with an increased risk of developing breast cancer compared with patients without PHTP. Little is known about the underlying risk factors. The aim of our study is to describe a cohort of patients with PHPT and breast cancer.
Methods: Retrospective study from a prospectively kept database of patients with PHPT treated by our group between January 2015 and July 2017 who had been diagnosed with breast cancer. The patients’ characteristics were obtained and analysed from the electronic medical records. Patients without complete medical records were not included in our study. All data were collected in a non-identifiable fashion in accordance with the principles outlined in the Declaration of Helsinki and as required for our institutional review board approval.
RESULTS AND DISCUSSION: A total of ten patients from a database of 75 patients were included in this study. All patients were female, the mean age was 59.2 years. The mean preoperative calcium, PTH and vitamin D was 10.1 mg/dL, 99.6 pg/mL and 25.5 ng/dL, respectively. Significant decreased of intraoperative PTH and postoperative calcium and PTH were achieved after surgical treatment. Pathology reported that 50% of the cases were secondary to a single adenoma (five patients) and 50% (five patients) of cases with hyperplastic parathyroid glands. Unilateral (70%), stages I or II (70%), invasive ductal breast carcinoma (90%) was the most common diagnosis. The immunohistochemical status reported that 80% of patients had positive hormone receptors. The mean time between breast cancer and PHPT operations was 89.5 months.
Conclusion: Breast cancer and PHPT share several common characteristics, which has led to the postulation of common etiological pathways. However, the exact pathogenesis and the relationship between breast cancers and PHPT still remains obscure. PHTP should be considered as a possible cause of hypercalcemia in patients with non-aggressive breast cancer. We suggest that serum PTH should be determined in all breast cancer patients with increased serum calcium concentration, especially in those with no evidence of metastatic disease.
