Table 5.
Anatomic site of leukoplakia and histopathology in the case-cohort component of the study
| Characteristic | Subcohort of patients with precancer (n = 500)* | All patients with oral precancer who progressed to cancer (n = 96)* |
|---|---|---|
| No. (%) | No. (%) | |
| Anatomic site of leukoplakia | ||
| Lip | 57 (11.4) | 2 (2.1) |
| Tongue | 193 (38.8) | 66 (68.8) |
| Gingiva | 102 (20.5) | 1 (1.0) |
| Floor of mouth | 17 (3.4) | 11 (11.5) |
| Palate | 26 (5.2) | 8 (8.3) |
| Other mouth | 103 (20.7) | 8 (8.3) |
| Histopathology | ||
| No dysplasia, hyperplasia, or hyperkeratosis | 422 (84.7) | 38 (39.6) |
| Mild dysplasia | 42 (8.4) | 18 (18.8) |
| Moderate dysplasia | 16 (3.2) | 7 (7.3) |
| Severe dysplasia | 9 (1.8) | 8 (8.3) |
| Cancer† | 9 (1.8) | 25 (26.0) |
*
In the case-cohort study, cases included all patients (100%) with leukoplakia who progressed to oral cancer (n = 96) and controls included a random subcohort of all the 1888 patients with leukoplakia who received a biopsy (n = 500, 26.5%). See Methods for additional details. Information on anatomic site and histopathology was manually abstracted from pathology reports. Numbers do not add to 500 because n = 2 incomplete pathology reports were excluded from analyses.
†
Denotes a result of cancer on the pathology report of a biopsy initially indicated clinically as oral leukoplakia.