Increase in PD-L1 expression after pre-operative radiotherapy for soft tissue sarcoma

Figures & data

Table 1. Baseline patient and treatment characteristics of irradiated patients.

	(n = 46)
Median Age (range) in years	61.0 (31.0 – 85.7)
Gender
Male	28 (60.9%)
Female	18 (39.1%)
T stage
T1-T1b	3 (6.5%)
T2 a	3 (6.5%)
T2b	40 (87.0%)
Grade
1–2	9 (19.6%)
3	37 (80.4%)
Histologic Subtypes
Undifferentiated Pleomorphic Sarcoma	33 (71.7%)
Liposarcoma	8 (17.4%)
Leiomyosarcoma	3 (6.5%)
Other	4 (8.7%)
Tumor Location
Upper Extremity	4 (8.8%)
Lower Extremity	35 (76.1%)
Abdomen/Pelvis	7 (15.2%)
Radiation Dose
50 Gy, 25fractions	42 (89.7%)
50.4 Gy, 28 fractions	4 (10.3%)
Median (Range), in Days, from Last Day of XRT to Surgery	28 (13–54)
Post-operative Chemotherapy
No	39 (84.8%)
Yes	7 (15.2%)

Figure 1. PD-L1 expression in undifferentiated pleomorphic sarcoma pre (A-D) and post (E-H) radiation therapy. Prior to radiation therapy, tumor cells and tumor associated macrophages are negative for PD-L1 (C-D). After radiation therapy, both tumor cells (straight arrows) and macrophages (curved arrows) are positive for PD-L1. A, C, E, G: 10x; B, D, F, H: 40x.

Table 2. Characteristics of 5 patients with increased PD-L1 expression after pre-operative radiation therapy.

Gender	Age	Location	T stage	Grade	Histologic Subtype	Time Between Pre-Op RT & Sx (days)	Total Dose	% PDL1 staining at biopsy	% PDL1 staining at surgery/after RT
Male	36	Lower Limb	T2b	3	Epitheliod	26	50 Gy/ 25 fx	0	> 1
Male	41	Lower Limb	T2b	3	UPS	27	50 Gy/ 25 fx	0	> 1
Female	60	Lower Limb	T2b	3	UPS	35	50 Gy/ 25 fx	0	> 1
Male	56	Lower Limb	T2b	3	UPS	17	50 Gy/ 25 fx	0	> 1
Female	70	Lower Limb	T2b	3	UPS	42	50 Gy/ 25 fx	0	> 1

Gy/fx = Gray/fraction; RT = radiation therapy; Sx = surgery; UPS = undifferentiated pleomorphic sarcoma.

Table 3. Baseline characteristics of patients with PD-L1 positive and negative expression on tumor-associated macrophages.

	PD-L1 positive (n = 21)	PD-L1 negative (n = 25)
Median Age (years)	58.9	61.0	p = 0.721
Gender
Male	11 (52.4%)	16 (64.0%)
Female	10 (47.6%)	9 (36.0%)	p = 0.550
T stage
T1 a-T1b	1 (4.8%)	2 (8.0%)	p = 0.673
T2 a	1 (4.8%)	2 (8.0%)
T2b	19 (90.4%)	21 (84%)
Grade
1–2	4 (19.1%)	7 (28.0%)	p = 0.514
3	17 (80.9%)	18 (72.0%)
Histologic Subtypes
Undifferentiated Plemorphic Sarcoma	14 (66.7%)	18 (72.0%)	p = 0.755
Liposarcoma	5 (23.8%)	3 (12.0%)
Leimyosarcoma	2 (9.5%)	1 (4.0%)
Other	0 (0%)	3 (12.0%)
Tumor Location
Upper Extremity	1 (4.8%)	2 (8.0%)	p = 0.429
Lower Extremity	19 (90.4%)	20 (80%)
Abdomen/Pelvis	1 (4.8%)	3 (12.0%)
Post-operative Chemotherapy
Yes	4 (19.1%)	3 (12.0%)	p = 0.880
No	17 (80.9%)	22 (88.0%)
Days from Completing XRT to surgery
Median (range)	28 (13–42)	28 (18–54)	p = 0.373

Figure 2. Comparing distant metastases free survival, via Kaplan-Meier plots, between sarcoma patients who express and do not express PD-L1 on macrophages after pre-operative radiation therapy.