Table 2.

Correlation of PD-L1 expression by tumor cells with the presence of immune infiltrates in 67 MCC specimens

Tumor PD-L1(−), n (%)Tumor PD-L1+, n (%)a
Tumor sitenTIL(−)TIL+bTIL (−)TIL +bP valuec
Primary298 (50)8 (50)0 (0)13 (100)0.003
Metastasis3812 (55)10 (45)0 (0)16 (100)<0.001
All6720 (53)18 (47)0 (0)29 (100)<0.001
  • aTumor cells were considered PD-L1+ if ≥5% of cells had membranous (cell surface) PD-L1 expression.

  • bTILs were considered positive if infiltrates were mild, moderate, or severe (scores 1–3; see Materials and Methods).

  • cFisher exact test.