Development and Validation of a Nomogram for Predicting Recurrence-Free Survival of Surgical Resected Retroperitoneal Liposarcoma

Figures & data

Table 1 Demographic, Clinicopathologic and Treatment Characteristics of All Patients, as Well as Patients in Training and Test Set

Variables	Total (n=447)	Training Set (n= 313)	Test Set (n=134)	p value
Gender
Male	218	148	70	0.337
Female	229	165	64
Age (yr) [median (IQR)]	55, 44–66	56, 45–67	54, 44–64	0.172
Presentation status
Primary	153	104	49	0.495
Recurrence	294	209	85
Chemotherapy				0.437
Yes	52	34	18
No	395	279	116
Radiation therapy				0.695
Yes	27	18	9
No	420	295	125
Location
Left	232	162	70	0.926
Right	215	151	64
Size(cm) [median (IQR)]	17, 9–25	17, 9–25	17, 8–26	0.735
Organ invasion
Yes	377	265	112	0.773
No	70	48	22
Histologic subtypes
Well-diferentiated (WDLPS)	208	152	56	0.362
Dediferentiated (DDLPS)	187	128	59
Myxoid/Round cell (MLPS)	40	24	16
Pleomorphic (PLPS)	12	9	3
FNCLCC
Grade 1	127	94	33	0.506
Grade 2	198	136	62
Grade 3	122	83	39
Number of resected organs
≤1	190	126	64	0.141
>1	257	187	70

Table 2 Results of the Univariable Cox Models and Wald Test for Backward Selected Variables

	COX Univariable			Wald Test
	OR	95% CI	p value	p value
Gender (Male)	1.142	0.779–1.675	0.495	0.0219
Age	0.997	0.981–1.014	0.761	0.0735
Presentation status (Primary)	2.524	1.597–3.990	<0.001	<0.001
Location (Left)	1.467	0.996–2.160	0.052
Size	0.989	0.968–1.012	0.347
Organ invasion (Yes)	0.493	0.257–0.947	0.034	0.009
Histologic subtypes			<0.001
DD VS WD	1.050	0.252–4.374	0.947
Myxoid/Round Cell VS WD	2.631	0.642–10.787	0.179
Pleomorphic VS WD	1.964	0.443–8.705	0.375
FNCLCC			<0.001
Grade 2 VS Grade 1	0.342	0.203–0.573	<0.001	0.042
Grade 3 VS Grade 1	0.492	0.321–0.755	0.001	<0.001
Number of resected organs (≤1)	1.197	0.812–1.765	0.363

Figure 1 Nomogram for 1-, 2- and 5-year recurrence-free survival in patients with retroperitoneal liposarcoma after surgery.

Figure 2 Calibration plots for predicting 1-, 2- and 5-year recurrence-free survival in the training and test sets. X-axis: bootstrap-predicted survival; y-axis: actual outcome.

Figure 3 Kaplan–Meier curves of recurrence-free survival for patients with retroperitoneal liposarcoma after surgery in the high- and low-risk groups. (A) Training set; (B) test set.