Table 2.
Morphologic features and expression of various proteins as evaluated by immunohistochemistry according to histological subtype of malignant mesothelioma (n = 82)
| Epithelioid (n = 73) | Sarcomatoid (n = 9) | P value* | |
|---|---|---|---|
| Tumor factors | |||
| Nuclear grade, n (%) | |||
| 1 | 4 (4.9%) | 2 (2.4%) | |
| 2 | 45 (54.9%) | 7 (8.5%) | .01 |
| 3 | 24 (29.3%) | 0 | |
| Cellularity as mean # of cells/mm2 | 71.14 | 53.22 | <.005 |
| BAP‐1, n (%) | |||
| Loss of expression | 56 (68.3%) | 6 (7.3%) | .38 |
| P53 mean # of positive cells/mm2 | 2.74 | 0.66 | <.005 |
| Ki‐67 | 1.86 | 1.98 | .89 |
| TUNEL | 20.20 | 14.48 | .35 |
| MCs PD‐L1 | 0.76 | 4.43 | .32 |
| PD‐1 | 0.45 | 0.35 | .43 |
| MLH1 | 48.87 | 35.22 | .13 |
| MSH2 | 47.92 | 41.28 | .51 |
| MSH6 | 55.85 | 52.80 | .76 |
| PMS2 | 41.99 | 23.35 | .01 |
| Microenvironment factors | |||
| Hyaluronic acid mean density/mm3 | 6.57 | 10.73 | .05 |
| Elastin mean density/mm3 | 6.08 | 2.30 | <.005 |
| Total collagen fibers mean density/mm3 | 12.05 | 32.71 | <.005 |
| Collagen I mean density/mm3 | 1.10 | 0.16 | <.005 |
| Collagen V mean density/mm3 | 4.41 | 4.45 | .97 |
| CD4 mean # of cells/mm2 | 135.65 | 161.45 | .83 |
| CD8 mean # of cells/mm2 | 62.40 | 6.54 | <.005 |
| CD20 mean # of cells/mm2 | 110.02 | 5.79 | <.005 |
| CD68 mean # of cells/mm2 | 21.70 | 16.14 | .26 |
Abbreviation: MCs, malignant cells.
*
The Chi‐square test and t test were used to detect differences in categorical and continuous variables, respectively, between groups of patients. A P value ≤ .05 was considered statistically significant.