Hypercalcemia in case of multiple myeloma in Latvia 2009-2013 data

Background
Multiple myeloma is the second mosl common hematologic malignancy found in adutt population. Hypercalcemia is its most common metabolic complication potentially leading to subsequent acute kidney injury and coma. Typically nonspecific clinicalfeatures of hypercalcemia can delay quick recognition of its development therefore it is significant to reveal additional risk groups of patients with multiple myeloma who can develop hypercalcemia in the progressive stages of the disease. lt is not clear, whether there are any differences between patients who present hypercalcemia at the moment of diagnosing multiple myeloma and the patients who develop hypercalcemia only later in the course of the disease.
Objectives
To identify differences between patients with hypercalcemia at the time of diagnosis and patients who have hypercalcemia only later in the course of the disease, and to analyze wheather the incidence of hypercalcemia is higher in active stages of multiple myeloma, which is defined with high levels of M gradient in serum or urine.
Materials
332 clinical reviews of multiple myeloma patients in Riga Eastern Clinical University Hospital , Linezers'were analyzed in the period of time from January 2009 till December 2013.
Results
Hypercalcemia was found in 21% (70) of patients with multiple myeloma. The average age of the myeloma patients was 67.3 at the moment of diagnosis but the average age for the patients that developed hypercalcemia was 65.2. Multiple myeloma is more common amongst women, 1.35 times, but amongst patients that developed hypercalcemia, there were 56% (39 patients) women and 44o/o (31 patients) men, so it is 1.25 times more common for women. As the data showed in the last couple of years patients diagnosed with multiple myeloma presented higher incidence of hypercalcemia in the early course of the disease in comparison to later stages of the disease. Hypercalcemia early in the course of multiple myeloma was associated with higher I maximal average levels of calcium (3,2 mmol/l vs. 2,86 mmol/l), higher mortality (77% vs. 54%) after the first presentation of hypercalcemia when compared with hypercalcemia presenting only late in the course of the disease. No significant differences were found comparing survival in patients with hypercalcemia at the moment of diagnosing multiple myeloma (8,4 months) and hypercalcemia developing only later in course of the disease (9,3 months). High association (64%) between hypercalcemia and active stages of the disease was found, particularly in patients presenting with hypercalcemia at the moment of diagnosing multiple myeloma (84%).
Conclusions
1. Hypercalcemia is more common for slightly younger patients in comparison with the average multiple myeloma patients in Latvia.
2. ln Latvia,multiple myeloma is more common amongst women, that varies from the data in the world, so also hypercalcemia is more common amongst women.
3. Hypercalcemia is not as common for muftiple myeloma patients in Latvia as it is in the world (25-33%), and, in the last two years, it has decreased in comparison with the data at the begining of the research.
4. Higher levels of calcium and the development of hypercalcemia in early course of the disease in multiple myeloma patients is associated with adverse outcome, higher mortality, but not with the decreased survival rates.
5. The tendency of hypercalcemia developing more ofren in the active stages of the disease shows the necessity for controlling serum levels of calcium at the moment of setting the diagnosis of multiple myeloma as well as in its progressive stages.
6. The admission of lately in Latvia established therapeutic drug for multiple myeloma treatment bortezomib might be associated with the decreased incidence of hypercalcemia developing only later in the disease thus indirectly indicating the efficiency of applied therapy.
7. The increasing incidence of hypercalcemia found in patients initially at the moment of diagnosing multiple myeloma could show the tendency for diagnosing multiple myeloma in later stages but the further researches are still necessary to approve this assumption.