Table 2. Comparison of tumour marker expression in low- and high-grade serous ovarian carcinomas according to morphological classification.
| Immunohistochemistry expression | Low-grade serous ovarian carcinoma (LGSOC) n (%) | High-grade serous ovarian carcinoma (HGSOC) n (%) | 1p value |
|---|---|---|---|
| WT1 expression* | |||
| Negative (complete absence to <1%) | 6 (28.6) | 36 (42.9) | |
| Positive (≥1%) | 15 (71.4) | 48 (57.1) | 0.32 |
| p53 expression | |||
| Focal (≥1% and <70%) | 2 (9.5) | 1 (1.2) | |
| Complete absence | 17 (81.0) | 26 (30.6) | |
| Diffuse (≥70%) | 2 (9.5) | 58 (68.2) | <0.0001 |
| p16 expression† | |||
| Negative (complete absence to < 90%) | 19 (90.5) | 34 (41.5) | |
| Positive (≥90%) | 2 (9.5) | 48 (58.5) | <0.001 |
| IHC p53/p16 index | |||
| Low-grade pattern (p53 staining in ≥1% and <70% and/or p53 complete absence + p16 <90%) | 19 (90.5) | 10 (11.9) | 2k = 0.68 |
| High-grade pattern (p53 ≥70% or p53 complete absence + p16 ≥90%) | 2 (9.5) | 74 (88.1) | p < 0001 |
LGSOC: low-grade serous ovarian carcinoma; HGSOC: high-grade ovarian serous carcinoma; *1 woman with HGSOC and †3 women with HGSOC had missing data due to exhaustion of tumour material in the paraffin blocks; statistically significant differences are in bold; 1p values were calculated using the Chi-square or Fisher exact test; 2Kappa Cohen.