Table 1.

Patients’ characteristics

Patients’ characteristics	N=35	%
Center 1	20	57.1
Center 2	15	42.9
Sarcoma type
Soft tissue sarcoma	27	77.1
Osteosarcoma	8	22.9
Gender
Female	18	51.4
Male	17	48.6
Anti-PD-1 ICI agent
Pembrolizumab	30	85.7
Nivolumab	5	14.3
Age at anti-PD-1 therapy start
Median (range)	50 (23–81)
ECOG at anti-PD-1 therapy start
0	14	40
1	7	20
2	6	17.1
3	3	8.6
4	2	5.7
Missing	3	8.6
Time to metastases in months
Median (range)	18.9 (0–108.3)
Therapy lines prior to anti-PD-1 therapy
Median (range)	3 (0–9)
No of metastatic organ sites at anti-PD-1 therapy start
Median (range)	2 (0–5)
No of received cycles of anti-PD-1 therapy
Median (range)	4.5 (1–42)
Anti-PD-1 ICI therapy stopped due to AE
Yes	3	8.6
No	32	91.4
PFS (from anti-PD-1 ICI therapy start), months
Median (range)	3 (0.3–32.6)
OS (from anti-PD-1 ICI therapy start), months
Median (range)	16.5 (0.3–44.2)
OS (from diagnosis of primary tumor), months
Median (range)	89.6 (9.4–228.6)
Deceased
Yes	19	54.3
No	16	45.7

AE, adverse events; ECOG, Eastern Cooperative Oncology Group; ICI, immune checkpoint inhibitor; OS, overall survival; PD-1, programmed cell death 1; PFS, progression-free survival.