Table 4.

Univariate analysis of the prognostic factors^a

Type	Factor	Local control		MMFS		OS		PFS
		χ2	P-value	χ2	P-value	χ2	P-value	χ2	P-value
SBP	Age	0.032	0.858	0.543	0.461	1.398	0.237	0.840	0.360
	Sex	0.410	0.552	0.009	0.923	0.023	0.879	0.034	0.853
	Tumor size	6.221	0.045	9.273	0.010	7.196	0.027	11.624	0.003
	Radiotherapy	1.237	0.266	0.055	0.814	0.000	0.998	0.080	0.777
	Serum M protein in IF	5.878	0.015	7.708	0.005	10.183	0.001	2.515	0.113
	Detected BJP	4.769	0.092	4.912	0.086	3.989	0.136	8.104	0.017
	Serum β2 microglobulin	1.844	0.175	4.462	0.035	5.575	0.018	1.113	0.287
EMP	Age	0.429	0.513	0.667	0.414	1.505	0.220	1.131	0.288
	Sex	1.000	0.317	1.500	0.221	0.042	0.837	0.016	0.899
	Tumor size	1.000	0.607	1.500	0.572	0.964	0.617	0.596	0.742
	Radiotherapy	19	0.000	4.000	0.046	0.316	0.574	0.182	0.669
	Serum M protein in IF	0.111	0.739	1.500	0.221	0.435	0.509	2.149	0.143
	Detected BJP	0.333	0.864	4.000	0.135	0.932	0.628	0.942	0.624
	Serum β2 microglobulin	4.000	0.046	4.000	0.046	0.553	0.457	0.952	0.329

Note:

^aLogrank test.

Abbreviations: BJP, Bence Jones protein; EMP, extramedullary plasmacytoma; IF, immunofixation electrophoresis; MM, multiple myeloma; MMFS, multiple myeloma–free survival; OS, overall survival; PFS, progression-free survival; RT, radiotherapy; SBP, solitary bone plasmacytoma.