Paraneoplastic Humorally Mediated Hypercalcemia Induced by Parathyroid Hormone-Related Protein in Gynecologic Malignancies: A Systematic Review

Humoral hypercalcemia of malignancy (HHM) is a metabolic phenomenon that is mediated by the paraneoplastic secretion of parathyroid hormone-related peptide (PTHrP). Gynecologic malignant neoplasms complicated by HHM have been reported for organs such as the uterus, cervix, ovary, vulva and the vagina. The purpose of our study was to perform a review of the published cases in the literature and, further, to identify parameters with effect on outcome. Among 34 women with gynecologic neoplasms, 22 suffered from ovarian and 6 from uterine malignancies, while 3 had vulvar and another 3 cervical cancer. Furthermore, clear cell carcinoma was the predominant histology associated with PTH-rP expression. A significant correlation was found between serum calcium and PTH-rP levels. Treatment of hypercalcemia was successful in all cases; pamidronate was utilized in 8 patients. Ovarian cancer patients with severe hypercalcemia and high PTH-rP serum levels had shorter survival compared to their counterparts with mild hypercalcemia or moderately elevated PTH-rP serum levels, but the differences were not statistically significant.