Table 3. Performance comparison of the proposed MIL method between different histological subtypes in test datasets and external validation dataset.
| Standard metrics | Histological subtype: I (%) (95% CI) | Histological subtype: II (%) (95% CI) | Histological subtype: mixed (%) (95% CI) |
|---|---|---|---|
| Internal test dataset (420 WSIs from 228 patients) | |||
| AUC | 92.7 (89.8–95.7) | 97.9 (94.6–100.0) | 92.9 (88.1–97.7) |
| Sensitivity | 80.2 (70.6–87.8) | 97.0 (84.2–99.9) | 95.3 (86.9–99.0) |
| Specificity | 92.2 (88.4–95.0) | 95.1 (83.5–99.4) | 80.4 (66.1–90.6) |
| PPV | 76.8 (68.2–85.5) | 94.1 (80.6–99.8) | 87.1 (76.3–97.1) |
| NPV | 93.5 (89.5–95.9) | 97.5 (86.7–99.7) | 92.5 (80.1–96.7) |
| External validation dataset (533 WSIs from 261 patients) | |||
| AUC | 78.3 (74.1–82.5) | 76.2 (59.3–93.1) | 63.6 (48.3–79.0) |
| Sensitivity | 60.8 (54.5–66.8) | 62.5 (40.6–81.2) | 42.4 (25.5–60.8) |
| Specificity | 84.3 (78.4–89.1) | 100.0 (59.0–NaN) | 94.1 (71.3–99.9) |
| PPV | 83.3 (77.2–86.7) | 100.0 (75.5–100.0) | 93.3 (68.5–98.7) |
| NPV | 62.4 (56.2–71.6) | 43.8 (24.2–NaN) | 45.7 (28.1–97.2) |
Histological subtype I: endometrioid adenocarcinoma as the main histological type and mucinous adenocarcinoma; Histological subtype II: non endometrioid adenocarcinoma; Mixed subtype: composing of subtype I + II, where at least one component is either serous or clear cell. MIL, multiple instance-learning; WSI, whole slide image; AUC, area under the curve; PPV, positive predictive value; NPV, negative predictive value; NaN, not a number.