Breast cancer associated with primary hyperparathyroidism: A nested case control study

Abstract

Sophie Norenstedt1,7, Fredrik Granath2, Anders Ekbom2, Jonas Bergh3, Mats Lambe4, Jan Adolfsson5, Fredrik Warnberg6, Jan Zedenius1,7, Inga-Lena Nilsson1,71Department of Molecular Medicine and Surgery, 2Department of Medicine, 3Department of Oncology and Pathology, Karolinska Institutet and Cancer Center Radiumhemmet, Karolinska University Hospital, Stockholm; 4Regional Oncology Centre, Uppsala; 5Oncologic Center, Karolinska University Hospital and CLINTEC Department, Karolinska Institutet, Stockholm; 6Department of Surgery, Uppsala Academic Hospital, Uppsala University; 7Endocrine Surgery Unit, Karolinska University Hospital, Stockholm, SwedenBackground: Primary hyperparathyroidism (pHPT) is associated with an increased risk of developing breast cancer, but little is known about the underlying factors. The aim of this study was to compare women with a history of pHPT and a reference population in terms of standard factors predictive of prognosis and response to therapy for breast cancer.Methods: We analyzed data collected from the National Swedish Cancer Register and from two regional oncologic center registries. Seventy-one women with breast cancer and a history of parathyroid adenomectomy were compared with 338 matched controls with breast cancer only. Tumor size, stage, hormone receptor status, lymph node status, cause of death, and cumulative survival were analyzed.Results: The mean age was 69 ± 11 years (95% confidence interval [CI]: 68–70) in both groups and the mean time interval between the parathyroid surgery and breast cancer diagnosis was 91 ± 68 months (95% CI: 72–111). There were no differences between the two groups regarding size, stage, lymph node metastases, or survival, but none of the cases with a history of pHPT were found in Stage III or IV.Conclusion: In conclusion, factors predictive of prognosis and response to therapy in women with a history of pHPT and breast cancer are similar to those in breast cancer patients without pHPT.Keywords: breast cancer, primary hyperparathyroidism, prognostic factors