Table 1.

Demographic features of patients and tissues.

DemographicsN (%)
Age41–83 (median, 63)
Gender
 Male18 (50)
 Female18 (50)
Primary site
 Acral17 (47.2)
 Mucosal10 (27.8)
 Cutaneous5 (13.9)
 Othersa3 (8.3)
 Unknown1 (2.8)
Stage
 Locally advancedb3 (8.3)
 Metastatic33 (91.7)
Biopsy site characteristic
 Skin10 (27.8)
 Non-skinc26 (72.2)
Biopsy location type
 Primary16 (44.4)
 Metastatic20 (55.6)
Tumor fraction
 ≥80%30 (83.3)
 <80%6 (16.7)d
Line of treatment for anti-PD-1/anti-PD-L1
 115
 210
 ≥38
 Not applicable4
  • aOther primary sites include dura, testicle, and conjunctiva.

  • bDefinite staging was not available in the 3 patients because primary sites were atypical (dura, conjunctiva, and rectum) without definite distant metastasis. All 3 patients experienced local recur.

  • cNon-skin biopsy sites include liver, lymph node, lung, bone, mucosa of conjunctiva, nasal cavity, gastrointestinal, and genital tract.

  • dSamples of 2 patients had tumor fraction of less than 50%.