OC 11-09COMBINED BIOMARKER EXPRESSION PATTERNS OF panHPVE4 AND p16INK4a CAN SUPPORT THE DIAGNOSIS AND GRADING OF CIN

17. Cervical neoplasia
A. Leeman 1, A. Kasius 1, M. Del Pino 2, A. Rodriguez 2, A. Torne 2, J. Ordi 3, H. Griffin 4, M. Van De Sandt 1, A. Molijn 1, F. Van Kemenade 5, D. Jenkins 1, J. Doorbar 4, W. Quint 1.
1DDL Diagnostic Laboratory, Visseringlaan 25, 2288 ER Rijswijk (Netherlands), 2Institute of Gynecology, Obstetrics and Neonatology, Hospital Clínic Clínic—Institut d´Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), University of Barcelona, Barcelona (Spain), 3Department of Pathology, Hospital Clínic, Barcelona (Spain), 4University of Cambridge, Department of Pathology, Tennis Court Road, Cambridge CB2 1QP (United Kingdom), 5Erasmus Medical Center, Department of Pathology, PO Box 2040, 3000 CA Rotterdam (Netherlands)

Background / Objectives

In the prevention of cervical cancer, cervical intraepithelial neoplasia grade 2 (CIN2) is currently the treatment threshold. However, reproducibility of CIN2 diagnosis is poor because it consists of a mixture of productive infections with a high chance of regression and transforming infections with a low change of regression. Biomarkers that can distinguish the two are urgently needed to reduce overtreatment. Expression patterns of panHPV-E4, a marker for human papillomavirus (HPV) life-cycle completion, and p16INK4a, which indicates transforming HPV-related lesion, may contribute.

Objective: To assess the expression patterns of immunohistochemical markers E4 and p16 in different grades of CIN.


Methods

Biopsies (78 negative, 54 CIN1, 65 CIN2, 52 CIN3, 1 adenocarcinoma in situ (AIS), 2 carcinomas) from 252 women were stained with E4 (panHPVE4 mAb FH1.1 detecting at least 16 HR-HPV types) and p16INK4a clone E6H4 (Ventana Medical Systems, Tucson, AZ). The worst lesion in a biopsy was scored by a pathologist for both markers with respect to the expression pattern: negative, extensive positivity or focal positivity for E4 and negative, patchy positivity, positivity in the lower 1/3 of the epithelium, positivity in the lower 2/3 or full thickness for p16.


Results

All histologically negative biopsies were negative for E4. Of the CIN1 lesions, 63% was negative, 30% showed extensive positivity and 7% showed focal positivity. In the CIN2 lesions, these numbers were resp. 65%, 11% and 24%. Of the CIN3 lesions, 98% was negative and 2% showed focal positivity. The AIS and both carcinomas were E4 negative.

With p16 staining, 18% of the histologically negative lesions showed patchy p16 positivity. For CIN1, CIN2 and CIN3 the positivity rates were resp. 83% (incl. 20% patchy), 98% and 96%. AIS and both carcinomas showed full thickness p16 positivity. Patterns of positivity of both biomarkers combined are shown in Table 1.

Table 1: E4 and p16 biomarker staining pattern in different grades of CIN
Diagnosis E4-/p16- E4+/p16- E4+/p16+ E4-/p16+
Negative 83% 0% 0% 18%
CIN1 9% 7% 30% 54%
CIN2 2% 0% 35% 63%
CIN3 4% 0% 2% 94%
AIS 0% 0% 0% 100%
Carcinoma 0% 0% 0% 100%
Total 73 4 40 135

 


Conclusion

E4 and p16 show distinct staining patterns in different grades of CIN. Histologically negative lesions are E4 negative with limited or no p16 staining. CIN3 lesions are E4 negative with extensive p16 staining. Neither histological CIN1 nor CIN2 are homogeneous groups and include lesions that can be classified as productive, with extensive E4 staining and lower 1/3 p16 staining, or as intermediate, with E4 staining and more extensive p16 staining, or as transforming, with extensive p16 expression. E4 and p16 combined staining could provide a clinically useful, more objective assessment of biopies.


References