Is High Grade Cervical Intraepithelial Neoplasia Ever Found on Follow Up of Equivocal and Low Positive Hybrid Capture 2 Results in Women 50 Years and Older?
Christiaan E de Vries, Rulong Shen, Adrian A Suarez. The Ohio State University, Columbus
Background: The Hybrid Capture 2 (HC2) test interpretation is currently the same for women of all ages despite the known age-dependent variation in prevalence of high-risk human papillomavirus (HPV) infection. Manufacturer's guidelines define an equivocal result as a Relative Light Unit/ Cut Off (RLU/CO) value of 1-2.5. The high grade cervical intraepithelial neoplasia (CIN2+) risk of older women with specimens in this range, as well as those with a low positive result (RLU/CO ratio of 2.5-10), has not been determined in our population.
Design: We identified all specimens from women over 50 years old with an equivocal or low positive HC2 HPV test result at our institution during a 13 month period from June 2009 to July 2010. These index Pap smear reports and their follow up cytology and histology reports were retrieved. All cases with atypia or CIN of any grade in these follow up specimens were reviewed at the microscope by two pathologists with expertise in cervical pathology and cytopathology.
Results: 102 equivocal (46, 45%) or low positive (56, 55%) HC2 tests on women >50 were identified. Index Pap smear reports were found for 88 cases and consisted of 37 NILM, 43 ASCUS, 2 ASC-H and 6 LSIL. Follow up specimens were available for 49 cases (48%) including 30 Pap smears and 33 cervical biopsies or endocervical curettages. Follow up cytologic specimens were 11 NILM, 4 ASCUS and 1 LSIL. 13 biopsy/curettage specimens were negative and 6 showed CIN1 or postmenopausal squamous atypia. 14 cases had both cytology and histology follow up; 5 NILM/Negative, 4 NILM/CIN1, 3 ASCUS/Negative, 1 LSIL/VAIN1 and 1 case was reported as ASCUS/CIN2. This latter case was classified as CIN1 after review including additional p16 and Ki67 IHC, it was also negative for HPV by in situ hybridization. Therefore, none of the 33 cases with histological follow up and 49 cases with histological or cytology follow up showed CIN2+. Of 24 cases with ASCUS cytology which underwent colposcopy, none showed CIN2+.
Conclusions: The absence of CIN2+ in women >50 with equivocal or low positive HC2 results suggests that the ideal laboratory interpretation and ultimate reporting of this test could be age specific. Older women could be spared from unnecessary follow up colposcopies and biopsies while maintaining high test sensitivity. We recommend the HC2 RLU/CO threshold levels be raised for older women undergoing reflex HPV DNA testing after ASCUS cytology on Pap smear.
Tuesday, March 1, 2011 9:30 AM
Poster Session III # 88, Tuesday Morning