Increased Hypercalcemia Trend.

e22117 Background: Hypercalcemia of malignancy (HCM) represents a complication of a variety of cancers. Bisphosphonates (BP) are routinely used to decrease skeletal related events in cases with osseous involvement. We hypothesized there would be a downtrend in HCM hospital admissions from 1999-2014 for breast (BC), lung (LC), renal (RC) cancers & multiple myeloma (MM) given the widespread use of BP. Methods: We analyzed data from the Healthcare Cost and Utilization Project’s National Inpatient Sample between 1999-2014 using ICD 9 codes for primary diagnosis of BC, LC, MM & RC and hypercalcemia as a secondary diagnosis. HCM % was evaluated. Chi-square testing determined significance. Hazard ratios (HR) of death during hospitalization related to HCM within 30 days were controlled for confounding factors like age, race, sex, income insurance status & comorbidities. Results: *w = weighted Conclusions: Hospital admissions remained relatively stable for the interval studied. HCM related to BC, LC & MM increased despite more aggressive BP use. RC did not show a significant change. Given the opposite trend in prevalence as expected, we believe this discrepancy is multifactorial. With advancements in therapies, patients live longer thus potentially increasing the prevalence of comorbidities such as HCM. Also, BP may be delaying the onset of HCM without decreasing incidence. PTHrP is less responsive to BP which could account for the increased frequency in BC & LC. With data becoming easily accessible and improved reporting during these 15 years studied, the incidence of HCM may have been under reported in the earlier years. HCM is an important metabolic disturbance with significant mortality in a variety of neoplasms that requires ongoing investigation for better preventive strategies. HCM Trends 1999 (%) 2014 (%) BC 0.52 1.91 N = 98,748 w* = 485,414 p = 0.0001 LC 2.57 4.05 N = 133,297 w = 656,021 p = 0.0001 MM 14.42 20.10 N = 56,295 w = 277,722 p = 0.0001 RC 1.41 1.49 N = 129,617 w = 638,856 p = 0.42 Admissions 1999 2014 BC N = 6,040 w: 29,917 N = 5,780 w: 28,900 LC N = 6,714 w: 33,147 N = 8,582 w: 42,910 MM N = 2,861 w: 14,176 N = 2,699 w: 13,495 RC N = 5,887 w: 29,061 N = 8,688 w: 43,440 Hospital Mortality HR 95%Cl P value BC 1.521 1.417-1.632 < 0.0001 LC 0.995 0.966 - 1.024 0.7202 MM 1.282 1.234 - 1.332 < 0.0001 RC 2.368 2.195 - 2.554 < 0.0001