ABSTRACT
Objective:To evaluate the value of p16 INK4a detected by p16 INK4a immunostaining as a new generation of cervical cytology for primary screening and secondary screening in population-based cervical cancer screening, and in improving cytological diagnosis. Methods:Between 2016 and 2018, 5 747 non-pregnant women aged 25-65 years with sexual history were recruited and underwent cervical cancer screening via high-risk (HR)-HPV/liquid-based cytological test (LCT) test in Shenzhen and surrounding areas. All slides were immuno-stained using p16 INK4a technology, among them, 902 cases were offered p16 INK4a detection during primary screening, and the remaining 4 845 cases were called-back by the virtue of abnormal HR-HPV and LCT results for p16 INK4a staining. Participants with complete LCT examination, HR-HPV test, p16 INK4a staining and histopathological examination results were included in this study. The performance of p16 INK4a in primary and secondary screening, and in assisting cytology to detect high grade squamous intraepithelial lesion [HSIL, including cervical intraepithelial neoplasia (CIN) Ⅱ or Ⅲ] or worse [HSIL (CIN Ⅱ) + or HSIL (CIN Ⅲ) +] were analyzed. Results:(1) One-thousand and ninety-seven cases with complete data of p16 INK4a and histology were included. Pathological diagnosis: 995 cases of normal cervix, 37 cases of low grade squamous intraepithelial lesion (LSIL), 64 cases of HSIL and one case of cervical cancer were found. Among them, 65 cases of HSIL (CIN Ⅱ) + and 34 cases of HSIL (CIN Ⅲ) + were detected. The positive rate of p16 INK4a in HSIL (CIN Ⅱ) + was higher than that in CINⅠ or normal pathology (89.2% vs 10.2%; P<0.01). (2) p16 INK4a as primary screening for HSIL (CIN Ⅱ) + or HSIL (CIN Ⅲ) + was equally sensitive to primary HR-HPV screening (89.2% vs 95.4%, 94.1% vs 94.1%; P>0.05), but more specific than HR-HPV screening (89.8% vs 82.5%, 87.7% vs 80.2%; P<0.05). p16 INK4a was equally sensitive and similarly specific to cytology (≥LSIL; P>0.05). (3) The specificity of LCT adjunctive p16 INK4a for detecting HSIL (CIN Ⅱ) + or HSIL (CIN Ⅲ) + were higher than that of LCT alone or adjunctive HR-HPV ( P<0.01), while the sensitivity were similar ( P>0.05). (4) p16 INK4a staining as secondary screening: p16 INK4a was significantly more specific (94.1% vs 89.7%, 91.9% vs 87.4%; P<0.01) and comparably sensitive (84.6% vs 90.8%, 88.2% vs 91.2%; P>0.05) to cytology for triaging primary HR-HPV screening. HPV 16/18 to colposcopy and triage other HR-HPV with p16 INK4a was equally sensitive (88.2% vs 94.1%; P=0.500) and more specific (88.3% vs 83.0%; P<0.01) than HPV 16/18 to colposcopy and triage other HR-HPV with LCT≥ atypical squamous cells of undetermined significance (ASCUS), and the referral rate decreased (14.0% vs 19.4%; P=0.005). Conclusions:For primary screening, p16 INK4a is equally specific to cytology and equally sensitive to HR-HPV screening. p16 INK4a alone could be an efficient triage after primary HR-HPV screening. In addition, p16 INK4a immunostaining could be used as an ancillary tool to cervical cytological diagnosis, and improves its accuracy in cervical cancer screening.
ABSTRACT
Objective To explore the relationship between cervical lesions and high risk HPV (HR-HPV) viral load reflected by the cycle threshold (Ct) values of Cobas 4800 HPV (Cobas 4800) system. Methods From August 2016 to September 2017, 7 000 women from Shenzhen, were recruited for cervical cancer screening with Cobas 4800 system and cytology co-test. Colposcope biopsies were performed on women who were positive of HPV 16, 18, and positive of HPV types other than 16, 18 with cytology [≥atypical squamous cell of undetermined signification (ASCUS)], or HPV negative but abnormal of cytology [≥low grade squamous intraepithelial lesion (LSIL)]. The Ct values of HPV 16, 18 and all combined other types coming from Cobas 4800 system were used as an indicator of viral load to analyze the relationship between type-specific HPV load and the cervical lesions. Results (1) Among the 7 000 screening women, 370 cases were positive for cervical cancer screening, 325 of them underwent colposcope biopsies, and coloposcopy referred rate was 87.8% (325/370). Among 325 women undergoing cervical biopsy, pathological diagnosis was 119 cases of normal cervical cervix, 151 cases of LSIL, and 55 cases of high-grade squamous intraepithelial lesion (HSIL) and above (HSIL+; including 53 cases of HSIL, 1 case of cervical adenocarcinoma, and 1 case of cervical squamous cell carcinoma). (2) The Ct value of HPV 16 was inversely correlated with the upgrading of the lesions (r=-0.617, P=0.000), and significant different among normal cervix,LSIL and HSIL+(35.4±4.5 vs 31.0±6.0 vs 26.5±4.0; F=25.537, P=0.000). There was no correlation between Ct value of HPV 18 and cervical lesions (r=-0.021, P=0.902). The Ct value of other 12 HPV types was statistically difference among normal normal cervix , HSIL+and cervicitis (33.0±5.3 vs 29.9±7.2 vs 29.8±5.8; F=5.087, P=0.007). Among them, LSIL and HSIL+ were significantly lower than normal cervix (P<0.05), but there was no significant difference between LSIL and HSIL+(P>0.05). Conclusion The Ct value of HPV 16 detecting in Cobas 4800 system as an indicator of virus load obviously correlates with different grades of cervical lesions, therefore could be a reference of cervical lesion existence and an indicator of lesion prognosis.