Table 2. Clinico-pathological predictors of SNB positivity by univariable unadjusted χ2 analysis and age–sex-adjusted logistic regression analysis.
| Factor | Factor groups | Overall χ2 P-value | Adjusted for age and sex OR (95% CI)* | Adjusted P-value |
|---|---|---|---|---|
| Breslow (mm) | 0.75–1 | <0.0001 | 1.0 | |
| 1.01–2 | 2.9 (1.5–5.5) | 0.001 | ||
| 2.01–4 | 7.5 (3.8–14.7) | <0.0001 | ||
| >4 | 9.9 (4.5–21.6) | <0.0001 | ||
| Clark's level | I/II/III | 0.001 | 1.0 | |
| IV | 1.5 (1.0–2.2) | 0.04 | ||
| V | 5.7 (2.3–14.1) | <0.0001 | ||
| Mitoses (mm2) | <1 | <0.0001 | 1.0 | |
| 1–6 | 3.5 (2.0–6.0) | <0.0001 | ||
| >6 | 6.7 (3.6–12.4) | <0.0001 | ||
| Ulceration | Absent | <0.0001 | 1.0 | |
| Present | 2.2 (1.5–3.3) | <0.0001 | ||
| Vessel invasion | Absent | 0.02 | 1.0 | |
| Present | 2.7 (1.1–6.6) | 0.03 | ||
| Microsatellites | Absent | 0.007 | 1.0 | |
| Present | 3.5 (1.3–9.5) | 0.02 | ||
| Tumour site | Arm | 0.04 | 1.0 | |
| Head/neck | 1.5 (0.7–3.2) | 0.3 | ||
| Leg | 1.9 (1.2–3.0) | 0.01 | ||
| Trunk | 1.8 (1.1–2.9) | 0.02 | ||
| Tumour subtype | SSM | 0.005 | 1.0 | |
| Nodular | 2.1 (1.3–3.3) | 0.002 | ||
| Other | 1.0 (0.5–1.9) | 1.0 | ||
| TILs | Absent | 0.07 | 1.0 | |
| Non-brisk | 0.9 (0.6–1.4) | 0.7 | ||
| Brisk | 0.6 (0.3–1.0) | 0.05 | ||
| Regression | Absent | 0.06 | 1.0 | |
| Present | 0.6 (0.4–1.0) | 0.05 |
Abbreviations: CI=confidence interval; OR=odds ratio; SNB=sentinel node biopsy; SSM=superficial spreading melanomas; TIL=tumour-infiltrating lymphocyte.