Evaluating murine double minute 2 status as a stratification tool for risk-adapted management in plasma cell neoplasms

Table 1 Descriptive data of age and laboratory parameters by murine double minute 2 status, mean ± SD

Parameter	MDM2-negative (n = 50)	MDM2-positive (n = 21)	Total (n = 71)
At diagnosis
Age (years)	57 (34-89) (59.1 ± 11.5)	58 (40-79) (58.5 ± 10.3)	58 (34-89) (58.9 ± 11.1)
Calcium (mg/dL)	10.6 (7.9-13.5) (10.9 ± 1.4)	10.4 (8.0-12.9) (10.6 ± 1.2)	10.5 (7.9-13.5) (10.8 ± 1.4)
Creatinine (mg/dL)	1.1 (0.5-3.5) (1.5 ± 0.8)	1.3 (0.7-4.0) (1.5 ± 0.8)	1.2 (0.5-4.0) (1.5 ± 0.8)
β2-microglobulin (mg/L)	4.9 (1.9-22.8) (6.6 ± 4.5)	4.7 (2.1-15.3) (5.9 ± 3.4)	4.9 (1.9-22.8) (6.4 ± 4.2)
LDH (U/L)	278 (149-790) (321.3 ± 159.5)	275 (188-450) (286.1 ± 85.4)	276 (149-790) (310.9 ± 142.0)
Total protein (g/dL)	10.2 (6.3-13.4) (10.4 ± 1.4)	10.5 (7.0-12.9) (10.3 ± 1.4)	10.4 (6.3-13.4) (10.4 ± 1.4)
Albumin (g/dL)	4.1 (2.0-5.9) (3.9 ± 1.2)	2.9 (2.0-5.3) (3.1 ± 0.9)	3.7 (2.0-5.9) (3.7 ± 1.2)
BM plasma cells (%)	20.5 (0-87) (28.2 ± 21.8)	26 (7-80) (34.2 ± 23.2)	22 (0-87) (30.0 ± 22.2)
Hemoglobin (g/dL)	8.4 (5.0-12.0) (8.2 ± 1.8)	8.0 (5.0-10.2) (8.1 ± 1.4)	8.3 (5.0-12.0) (8.2 ± 1.7)
At 12 weeks
Hemoglobin (g/dL)	10.0 (6.4-14.0) (9.7 ± 1.8)	9.4 (5.4-11.5) (9.3 ± 1.4)	10.0 (5.4-14.0) (9.6 ± 1.7)
β2-microglobulin (mg/L)	2.3 (0.5-9.3) (2.9 ± 1.9)	2.4 (0.9-9.6) (2.9 ± 1.8)	2.3 (0.5-9.6) (2.9 ± 1.9)
Creatinine (mg/dL)	8.9 (7.2-11.8) (8.9 ± 0.9)	8.9 (6.3-10.1) (8.8 ± 0.8)	8.9 (6.3-11.8) (8.9 ± 0.9)
Calcium (mg/dL)	1.1 (0.6-5.6) (1.3 ± 0.8)	1.3 (0.5-2.5) (1.3 ± 0.5)	1.1 (0.5-5.6) (1.3 ± 0.7)
Total protein (g/dL)	8.0 (5.1-12.8) (8.3 ± 1.6)	8.0 (5.7-11.9) (8.4 ± 1.8)	8.0 (5.1-12.8) (8.3 ± 1.6)

MDM2: Murine double minute 2; BM: Bone marrow; LDH: Lactate dehydrogenase.

Table 2 Treatment protocols among patients

Initial treatment type	Frequency	Percent (%)	Initial chemotherapy type	Frequency	Percent (%)
CTH	62	87.3	CyBorD	37	52.1
CTH and RTH	8	11.3	VAD	29	40.8
RTH	1	1.4	Daratumumab	4	5.6

CTH: Chemotherapy; RTH: Radiotherapy; CyBorD: Cyclophosphamide, bortezomib, and dexamethasone; VAD: Vincristine, adriamycin (doxorubicin), and dexamethasone.

Table 3 Comparison of relapse-free survival and overall survival between murine double minute 2-negative and murine double minute 2-positive patient groups

Parameter	MDM2-negative (n = 50)	MDM2-positive (n = 21)	P value
Median RFS (months)	68	22	< 0.001
Mean RFS (months)	62.93	21.98
Median OS (months)	Not reached1	35 (95%CI: 23-47)	0.401
Mean OS (months)	54.8 (95%CI: 42-67.6)	46.2 (95%CI: 33.9-58.5)

¹Median overall survival for the murine double minute 2-negative group was not reached.

RFS: Relapse-free survival; OS: Overall survival; CI: Confidence interval; MDM2: Murine double minute 2.