Table 2. Colorectal cancer (CRC) tissues have a higher rate of high-risk HPV infection, than both adjacent normal tissues (ANT) and colorectal adenoma tissues (CRA).
| Tissue | Total | Presence of HPV16/53 Infection | χ2 | P value | |
|---|---|---|---|---|---|
| Origins | n | Pos+ n (%, 95% CI) | Neg- n (%, 95% CI) | ||
| CRC | 95 | 46 (48.4, 38–58) | 49 (51.6, 42–62) | ||
| ANT | 50 | 15 (30.0, 17–42) | 35 (70.0, 83–57) | 4.6 | 0.033 |
| CRA | 50 | 14 (28.0, 16–40) | 36 (72.0, 60–84) | 5.6 | 0.018 |
Note: All HPV-positive tissues/cases were infected by HR-HPV subtypes. Among 46 HPV-positive CRC cases, 45 were HPV16-positive (45/46, 97.8%) and 1 was HPV53-positive (1/46, 2.2%). Furthermore, all 15 HPV-positive ANT tissues (15/15, 100%) and all 14 CRA tissues (14/14, 100%) were infected with HPV16. No other HPV types were detected in all of the above tissues. HPV infections of CRC cases were compared with those of ANT and CRA, respectively. Pos+ = positive; Neg- = negative; CI = confidence interval. CRC, colorectal cancer; ANT, adjacent normal tissues; CRA, colorectal adenoma that included 3 histologic subtypes: tubular adenoma, villous-tubular adenoma, and villous adenoma, among which no differences in HPV infection rate were found (χ2 = 1.2, P = 0.543).