Prognostic factors in solitary plasmacytoma of the bone: a multicenter Rare Cancer Network study

BMC Cancer

Table 3 Univariate analyses (logrank test)

	n	10-yr. OS (%)	%95 CI (%)	p-value	10-yr. DFS (%)	%95 CI (%)	p-value	10-yr. LC (%)	%95 CI (%)	p-value	10-yr. MM (%)	%95 CI (%)	p-value
All patients	206	52	43–61		25	15–35		79	69–89		72	62–82
Age (year)
≤ 60	103	63	50–76	<0.0001	29	16–42	0.02	79	64–94	0.46	67	53–81	0.007
>60	03	34	19–49		22	9–35		79	67–91		76	62–90
Gender
Female	73	52	36–68	0.98	38	23–53	0.79	88	79–97	0.60	58	43–73	0.77
Male	133	49	37–61		23	13–33		75	62–88		74	63–85
Site of plasmacytoma
Vertebra	102	52	38–66	0.99	19	4–34	0.89	89	79–98	0.07	79	64–94	0.39
Other	104	48	35–61		28	16–40		78	68–88		66	53–79
Largest tumor dimension (cm)
<5	45	67	36–98	0.001	24	7–41	0.73	87	75–99	0.47	79	58–100	0.31
≥ 5	59	57	42–72		34	19–49		78	65–91		58	42–74
NA	102	33	19–47		16	0–33		73	50–96		80	64–96
IgM subtype
Kappa	59	49	19–47	0.57	0	-	0.57	60	24–94	0.49	91	75–100	0.36
Lambda 100	31	61	40–81		35	16–54		87	69–100		65	46–84
NA	116	49	37–61		22	20–44		84	75–93		64	52–76
Type of treatment
RT alone	169	51	40–62	0.49	27	16–38	0.92	78	66–90	0.27	71	60–82	0.93
CT + RT 100	32	43	20–66		15	0–39		93	84-		77	54–100
2 Gy/fr equivalent RT dose (Gy) ^a
≥ 50	56	47	28–66	0.50	26	10–42	0.06	82	68–96	<0.0001^b	71	55–87	0.25
≥ 40 and <50	65	55	34–76		25	6–44		67	40–94		78	59–97
≥ 30 and <40	55	46	28–64		32	16–48		90	81–99		63	47–79
<30	25	37	13–61		17	0–43		96	88–100		81	53–100
No RT^c	5	0	-		0	-		0	-		33	0–86

OS: overall survival; CI: confidence interval; DFS: disease-free survival; LC: local control; MM: progression to multiple myeloma; NA: not available; CT: chemotherapy; RT: radiation therapy ^abiologically effective dose (BED) according to the linear-quadratic model.¹³ BED = nd(1+ [d÷α/β]) where n = number of fractions, d = dose per fraction, and α/β = 10 for plasmacytoma. ^bnot significant when excluding patients not receiving radiation therapy. ^cAll patients treated with surgery alone (with chemotherapy in one).

ISSN: 1471-2407