Mechanisms of Hypercalcemia in Non-Hodgkin Lymphoma and Associated Outcomes: A Retrospective Review.
INTRODUCTION
The etiology of hypercalcemia in non-Hodgkin lymphoma (NHL) has been most often attributed to either elevated serum levels of 1,25-dihydroxycholecalciferol (calcitriol) or parathyroid-related protein (PTHrP). In a single-center retrospective review, we evaluated the incidence of, and outcomes associated with, hypercalcemia in NHL.


PATIENTS AND METHODS
The medical records of patients with a histologically confirmed diagnosis of NHL and ≥ 1 episode of hypercalcemia were evaluated for demographic and lymphoma-specific factors, including the response to therapy and overall survival.


RESULTS
Fifty-four patients with NHL met the inclusion criteria. Most patients (57.4%) had diffuse large B-cell lymphoma, of which, 70% were the nongerminal center subtype. Approximately one half (42.6%) of the included patients had undergone serologic investigation into the etiology of hypercalcemia; however, only 17 patients (31.5%) had both a serum PTHrP and a calcitriol level properly collected. Of the 17 cases for which both a serum calcitriol and a PTHrP were collected, most (61.1%) were found to have neither an elevation of serum calcitriol nor an elevation of PTHrP. The degree of calcitriol elevation correlated with worse progression-free survival (P = .04) but not overall survival.


CONCLUSION
The major mechanism by which NHL patients develop hypercalcemia is not mediated by calcitriol or PTHrP. Hypercalcemia is most prevalent in patients with diffuse large B-cell lymphoma of the nongerminal cell subtype. Patients with calcitriol-mediated hypercalcemia showed a trend toward worse outcomes, suggesting that calcitriol might be a marker of high-grade lymphoma, transformation to such, or a surrogate for more advanced disease.
['Shallis|Rory M|RM|', 'Rome|Rachel S|RS|', 'Reagan|John L|JL|']
D002117:Calcitriol D005260:Female D006801:Humans D006934:Hypercalcemia D053208:Kaplan-Meier Estimate D016403:Lymphoma, Large B-Cell, Diffuse D008228:Lymphoma, Non-Hodgkin D008297:Male D008875:Middle Aged D017063:Outcome Assessment, Health Care D044162:Parathyroid Hormone-Related Protein D012189:Retrospective Studies
NHL Calcitriol PTHrP Survival