[Clinical characteristics of bone disease in multiple myeloma and clinical significance of monitoring bone metabolic markers].

ABSTRACT

OBJECTIVE: To observe the clinical characteristics of bone disease in patients with multiple myeloma (MM) and the clinical significance of monitoring bone metabolic markers. METHODS: The data of 178 MM cases newly diagnosed in Beijing Ji Shui Tan Hospital from January 2009 to June 2014 were reviewed to analysis the types and classification of bone disease and to observe the clinical characteristics of patients with different grades of bone disease. The levels of bone metabolic markers total procollagen type Ⅰ N-terminal peptide (tPINP) and ß C-terminal telopeptide of type Ⅰ collagen (ß-CTX) were monitored regularly in the two years following treatment in 66 cases. RESULTS: (1) Among the 178 newly diagnosed MM cases, 167 cases complained of pain in bones on first visit, 35 cases combined with hypercalcemia, 83 cases combined with osteoporosis, 154 cases combined with osteolytic bone destruction, and 73 cases combined with pathologic fracture. The most common osteolytic location was the spine. The most common fracture sites was the spine. (2) According to bone disease grading, the 178 cases were divided into group A (bone grade 0-2, n=51) and group B(bone grade 3-4, n=127). There were no significant differences between group A and group B in gender, median age, therapeutic effect/ineffec, median overall survival, median progress-free survival, mean serum lactic dehydrogenase, mean albumin, urine light chains and serum creatinine(all P>0.05). Compared with group A, group B had lower hemoglobin level[(99.78±29.93)vs (108.84±29.30) g/L], and higher blood calcium level[(2.47±0.40)vs (2.30±0.29) mmol/L], serum ß2-microglobuin level[(6.04±4.84)vs (4.12±3.97)mg/L], and bone marrow plasma cells percentage(33.30%±24.87% vs 23.51%±22.67%)(all P<0.05). (3) Before treatment, the levels of ß-CTX and tPINP in patients of group B(n=47) were higher than those in group A(n=19)(median 0.78 vs 0.42 µg/L, 60.95 vs 43.47 µg/L, both P<0.05). The ratio of ß-CTX /tPINP in group B was higher than that in group A (median 0.017 vs 0.012, P<0.05). After chemotherapy for 3 months, there were no differences in the level of tPINP compared with that before treatment in both group A and group B (both P>0.05), the level of ß-CTX decreased significantly compared with that before treatment in both groups(median 0.16 vs 0.42 µg/L, 0.26 vs 0.78 µg/L, both P<0.05); the ratio of ß-CTX /tPINP decreased significantly compared with that before treatment in both group A and in group B(median 0.008 vs 0.012, 0.011 vs 0.017, both P<0.05). There were no differences in the level of ß-CTX, tPINP and ß-CTX/tPINP ratio after treatment for 6 months, 1 year and 2 years compared with that after 3 months in both group A and group B (all P>0.05). (4)All patients were divided into two groups according to the therapeutic effect effective group included patients who reach the effect of partial remission or better remission(n=48), while ineffective group included patients who did not reach the effect of partial remission(n=18). Before treatment there were no differences in the level of ß-CTX, tPINP and ß-CTX/tPINP ratio between the effective groupand the ineffective group (all P>0.05). After chemotherapy for 3 months, there were no differences in the level of tPINP compared with that before treatment in both effective group and ineffective group (all P>0.05), but the level of ß-CTX decreased significantly compared with that before treatment both in effective group and ineffective group (median 0.24 vs 0.60 µg/L, 0.44 vs 0.95 µg/L, both P<0.05). The ratio of ß-CTX /tPINP decreased significantly compared with that before treatment both in effective group and ineffective group (median 0.005 vs 0.012, 0.005 vs 0.011, both P<0.05). There were no differences in the level of ß-CTX, tPINP and ß-CTX/tPINP ratio after treatment for 6 months, 1 year and 2 years compared with that for 3 months both in effective group and ineffective group (all P>0.05). CONCLUSIONS: Pain in bones, osteolysis and pathological fracture are the most common clinical manifestations in myeloma-related bone disease. The severity of bone disease can reflect the tumor load, but may not affect the therapeutic effect and the overall survival. The bone metabolic markers tPINP and ß-CTX can be used to evaluate the severity of myeloma-related bone disease at diagnosis and to monitor the effect of treatment for bone disease.