Table 1.

Patient characteristics

	Hematological malignancy N (%)	No hematological malignancy N (%)	P value
MM (total)	52 (100%)	257 (100%)
Gender			0.23
Male	37 (71.2%)	157 (61.1%)
Female	15 (28.8%)	100 (38.9%)
Age at diagnosis of skin cancer			n.s.
Median (IQR)	72.5 years (59.0–76.0)	67.0 years (53.0–75.0)
Primary site of skin cancer			0.38
Head and neck	13 (23.1%)	51 (19.8%)
Trunk	21 (40.4%)	97 (37.7%)
Extremities	12 (23.1%)	48 (18.6%)
Mucosa/others	2 (3.8%)	27 (10.4%)
Unknown primary	4 (7.6%)	34 (13.2%)
Median follow-up time (months, IQR)	8.7 (3.9–23.8)	15.0 (6.0–28.0)	n.s.
cSCC (total)	15 (100%)	59 (100%)
Gender
Male	12 (80%)	41 (69%)	0.65
Female	3 (20%)	18 (31%)
Age at diagnosis of skin cancer			n.s.
median (IQR)	76.0 years (70.0–78.0)	77.0 years (71.0–81.0)
Primary site of skin cancer			0.79
Head and neck	13 (86.7%)	43 (72.9%)
Trunk	2 (13.3%)	9 (15.3%)
Extremities	0 (0.0%)	5 (8,5%)
Mucosa	0 (0.0%)	1 (1.7%)
unknown primary	0 (0.0%)	1 (1.7%)
Median follow-up time (months, IQR)	6.2 (2.3–13.4)	6.0 (3.1–13.2)	n.s.
MCC (total)	17 (100%)	76 (100%)
Gender			0.82
Male	12 (70.6%)	53 (69.7%)
Female	5 (29.4%)	23 (30.3%)
Age at diagnosis of skin cancer			n.s.
Median (IQR)	70.0 years (63.0–78.5)	71.0 years (62.7–78.0)
Primary site of skin cancer			0.61
Head and neck	5 (29.4%)	20 (26.3%)
Trunk	4 (23.5%)	13 (17.1%)
Extremities	7 (41.2%)	29 (38.2%)
Unknown primary	1 (5.9%)	14 (18.4%)
Median follow-up time (months, IQR)	8.2 (4.0–13.2)	11.4 (4.1–19.1)	n.s.

Characteristics of all investigated patients treated with immune checkpoint inhibition (ICI) for advanced skin cancer. Comparisons are given with respective p values for each skin cancer entity in n=84 patients with and n=392 patients without concomitant hematological malignancy. Percentages are given per column. Median follow-up times were calculated from start of ICI therapy until last observation or death.

cSCC, cutaneous squamous cell carcinoma; MCC, Merkel cell carcinoma; MM, malignant melanoma.