PDL1 expression is an independent prognostic factor in localized GIST

Figures & data

Table 1. Histoclinical characteristics of patients and tumors

Characteristics^a	N (%)
Sex (139)
Female	50 (36%)
Male	89 (64%)
Age, years (79)
≤60	31 (39%)
<60	48 (61%)
median (range)	63 (26–85)
Site (139)
Gastric	109 (78%)
Small intestine	21 (15%)
Other	9 (6%)
Mutation^a (138)
KIT exon 11	88 (64%)
KIT exon 9	8 (6%)
PDGFRA exon 18	16 (12%)
Wild type (WT)	17 (12%)
Other^b	9 (7%)
AFIP risk (139)
Low	75 (54%)
Intermediate	25 (18%)
High	39 (28%)
Metastatic relapse (138)
No	111 (80%)
Yes	27 (20%)

^aThe number of patients with available information is shown between brackets; ^bKIT exons 13 (n = 1) and 17 (n = 2), PDGFRA exons 12 (n = 5), and 14 (n = 1).

Table 2. Correlations of PDL1 expression with histoclinical features

Characteristics*	N	Average PDL1 expression (min–max)	P-value
Sex (139)			0.07
Female	50	0.27 (−1.32–3.15)
Male	89	−0.07 (−2.13–2.24)
Age, years (79)			0.649
≤60	31	0.16 (−1.5–2.24)
<60	48	0.05 (−1.73–3.15)
Site (139)			0.37
Gastric	109	0.09 (−2.13–3.15)
Small intestine	21	−0.21 (−1.61–1.21)
Other	9	0.23 (−0.41–1.19)
Mutation (129)			0.89
KIT exon 11	88	0.08 (−2.13–2.36)
KIT exon 9	8	−0.18 (−0.67–0.48)
PDGFRA exon 18	16	−0.01 (−1.15–1.63)
Wild type (WT)	17	−0.01 (−1.61–3.15)
AFIP risk (139)			0.0194
Low	75	0.2 (−1.75–3.15)
Intermediate	25	0.19 (−1.13–2.36)
High	39	−0.32 (−2.13–1.67)
Metastatic relapse (138)			0.0029
No	111	0.18 (−1.75–3.15)
Yes	27	−0.46 (−2.13–1.19)

^aThe number of patients with available information is shown within parentheses.

Figure 1. Correlations of PDL1 expression with immune features. PDL1 expression levels reported as a box plot according to sample classifications based on gene expression signatures (A) including T cells (left) and CD8⁺ T cells (middle) metagenes and a prognostic immune kinase gene expression signature (right), and based on the probability of activation of immune pathways (B) including IFNα (left), IFNγ (middle), and TNFα (right). The P-values are indicated (Student's t-test) are indicated as follows: ***, P < 0.001.

Table 3. Univariate and multivariate prognostic analyses for metastasis-free survival

	Univariate analysis			Multivariate analysis
	N	Odds ratio [95%CI]	P-value	N	Odds ratio [95%CI]	P-value
Sex,
Male vs. Female	138	1.13 [1.00–1.26]	0.09	128	1.08 [0.98–1.19]	0.20
Age,
≤60 vs. >60 years	78	0.94 [0.81–1.08]	0.44
Site,
Other vs. Gastric	138	1.18 [0.94–1.48]	0.23
Small intestine vs. gastric	138	1.13 [0.96–1.32]	0.21
Mutation,
KIT exon 11 vs. WT	128	1.20 [1.01–1.43]	0.09	128	1.15 [1.00–1.32]	0.10
KIT exon 9 vs. WT	128	1.37 [1.03–1.82]	0.07	128	1.30 [1.04–1.63]	0.06
PDGFRA exon 18 vs. WT	128	1.00 [0.80–1.26]	0.98	128	1.08 [0.90–1.30]	0.48
AFIP risk,
Intermediate vs. low	138	1.22 [1.08–1.38]	0.0065	128	1.19 [1.05–1.35]	0.0226
High vs. low	138	1.78 [1.61–1.98]	< 0.0001	128	1.66 [1.49–1.86]	< 0.0001
PDL1 expression, High vs. low	138	0.74 [0.64–0.84]	0.0002	128	0.81 [0.72–0.92]	0.0056