Table 2.

Multivariate analysis of factors affecting survival in plasmacytoma (P- EM: Extramedullary plasmacytoma; P-Bone: Bone plasmacytoma).

Variable	No. (%)	HR (95% CI)
Age (years)
<65	2814 (55.7%)	Referent
≥65	2242 (44.3%)	3.46 (3.14–3.81)
Location
P-EM	1528 (30.2%)	Referent
P-Bone	3528 (69.8%)	1.48 (1.33–1.65)
Treatment
Neither Surgery nor Radiation	508 (10.0%)	Referent
Both Surgery and Radiation	1414 (28.0%)	0.41 (0.35–0.48)
Only Radiation	2491 (49.3%)	0.53 (0.46–0.60)
Only Surgery	643 (12.7%)	0.58 (0.48–0.69)
Model for Patients With Any Radiation (N=2816)
Radiation dose (Gy)
<40	703 (25.0%)	Referent
≥40	2113 (75.0%)	0.62 (0.54–0.72)
Age (years)
<65	1635 (58.1%)	Referent
≥65	1181 (41.9%)	3.17 (2.74–3.66)
Location
P-EM	768 (27.3%)	Referent
P-Bone	2048 (72.7%)	1.47 (1.24–1.73)
Treatment
Only Radiation	1803 (64.0%)	Referent
Both Surgery and Radiation	1013 (36.0%)	0.83 (0.71–0.96)
Model for P-Bone Primary Site (N=2048)
Radiation dose (Gy)
<40	572 (27.9%)	Referent
≥40	1476 (72.1%)	.66 (0.56–0.77)
Age (years)
<65	1183 (57.8%)	Referent
≥65	865 (42.2%)	3.38 (2.87–3.98)
Model for P-EM Primary Site (N=768)
Radiation dose (Gy)
<40	131 (17.1%)	Referent
≥40	637 (82.9%)	0.49 (0.35–0.67)
Age (years)
<65	452 (58.9%)	Referent
≥65	316 (41.1%)	2.79 (2.06–3.78)