Among human cervical neoplastic cells, the methylation indices of ADCYAP1 were 7.8 (95% confidence interval [95% CI], 7.0-8.6) in subjects with LSILs and 39.8 (95% CI, 29.0-54.7) in those with cervical cancer (P < 0.001); for PAX1, 7.2 (95% CI, 6.1-8.5) and 37.8 (95% CI, 27.1-52.7), respectively; for CADM1, 3.5 (95% CI, 3.0-4.0) and 17.7 (95% CI, 10.8-29.1), respectively; for MAL, 2.7 (95% CI, 2.5-3.0) and 13.0 (95% CI, 7.6-22.0), respectively (P < 0.001 for each).
Specifically, methylation of IGSF4 and DAPK1 was prevalent in SCC (75% and 75% of cases, respectively) and HSIL (59% and 71%, respectively) but was absent in LSIL and normal biopsy samples.
The areas under the curve for the best two-gene combination (IGSF4/DAPK1) and the best three-gene combination (IGSF4/DAPK1/HIC1) were not statistically different from the best individual tumor suppressor gene (IGSF4) in distinguishing HSIL samples from combined LSIL/negative samples.