Mark Schiffman

Heterogeneity in CIN3 diagnosis

In this issue of The Lancet Oncology, McCredie and colleagues report retrospective, long-term follow-up of 1063 women diagnosed with cervical intraepithelial neoplasia 3 (CIN3) in Auckland, New Zealand, from 1955 to 1976. A histopathology diagnosis of CIN3 implies abnormal, precancerous cell growth that spans greater than two-thirds of the entire epithelium, and can involve the full thickness (carcinoma in situ). In the 1960s, Green incorrectly believed he could distinguish incipient cancer from CIN3 (which he considered aetiologically distinct) by colposcopic examination and directed biopsies. He withheld treatment from many women diagnosed between 1965 and 1974. As McCredie and co-workers report, the cumulative 30-year risk of invasive cancer in the 143 women with only diagnostic biopsies, but no treatment, was 31·3% (95% CI 22·7–42·3); and the cumulative risk was 50·3% (37·3–64·9) in the subset of women with cytological evidence of persistent CIN3 within 2 years of diagnosis. Green’s study was never formally stopped, but active recruitment declined from the 1970s and large-scale prospective (albeit passive) follow-up continued until the late 1980s. McCredie and colleagues obtained permission from an ethical committee to verify ultimate outcomes to the end of 2000 in all women with CIN3, including those women included in Green’s study, both treated and untreated, based on linkage to New Zealand and neighbouring Australian registries. Their study shows starkly the now universally accepted importance of surgical treatment of large CIN3 lesions to prevent invasive cancer. Untreated women had 50–100-times the invasion risk of women properly treated by full excision. Partial treatments, eg, shallowcone resections, logically yielded intermediate risk reductions. These unique data solidify our understanding of CIN3 as the crucial target of cervical-cancer screening programmes, the defi nitive treatment threshold, and the optimum primary endpoint in studies of the natural history of human papillomavirus (HPV) and of cancer vaccines. Persistent, carcinogenic HPV infections cause almost all CIN3 and cervical cancer. To defi ne CIN3 as the surrogate endpoint for cervical cancer in research and clinical practice implies that

Predictors of human papillomavirus persistence among women with equivocal or mildly abnormal cytology.

We investigated short‐term persistence of human papillomavirus (HPV) infection among 2,408 women with low‐grade or equivocal cytological abnormalities followed for 24 months. Odds ratios (ORs) for persistence to the next 6‐month visit were estimated by a discrete time survival model. Prevalent HPV infections persisted longer in older women, but no association with age was found for incident HPV infections. Increased likelihood of persistence was found among current smokers of >20 cigarettes per day compared with smokers of ≤10 cigarettes per day (OR=1.43; 95% confidence interval [CI]: 1.02–2.01) and among current injectable contraceptive users (OR=1.15; 95% CI: 1.01–1.32). Persistence was more likely among infections with higher viral load (OR=2.05; 95% CI: 1.65–2.53) or with concurrent cytological abnormalities (OR=1.19; 95% CI: 1.03–1.39 and 1.29; 95% CI: 0.99–1.70 for ASCUS/LSIL and ASC‐H/HSIL, respectively). We conclude that new HPV infections in older women are not riskier by the metric of viral persistence than those in younger women. Other risk factors such as oral contraceptive use and multiparity that have been associated with cervical cancer or cervical intraepithelial neoplasia grade 3 were not associated with short‐term HPV persistence.

Molecular mapping of high-grade cervical intraepithelial neoplasia shows etiological dominance of HPV16

Women with high‐grade cervical intraepithelial neoplasia (HGCIN) frequently present with multiple cervical lesions and multiple concomitant Human papillomavirus (HPV) genotype infections. To elucidate HPV genotype attribution in different regions on the cervix, we performed molecular mapping of cervical disease in women with HGCIN. Thirteen subjects referred to colposcopy for abnormal cervical cancer screening results were included. A cervical smear and biopsies from 4 different areas on the cervix were collected. HPV genotyping using Linear Array (for cytology) or SPF10 LiPA25 (for histology) were performed in 13 smears, 52 whole sections from biopsies and 138 tissue regions isolated with laser capture microdissection (LCM). Twelve subjects had a diagnosis of CIN3 and one subject had a diagnosis of CIN2 based on the worst histology found in 4 biopsies. Eight of the 13 smears (62%) showed multiple genotype infections. Four of 13 women (31%) had multiple HPV infections in their biopsies. After performing LCM‐PCR, only one woman (8%) had two different carcinogenic HPV types in morphologically distinct, but colliding HGCIN lesions. HPV16 was identified as the causal type in all women with HPV16 in cytology. A large proportion of other HPV types found in cervical smears were not detected at the tissue level. Using tissue‐based genotyping and LCM‐PCR analysis, we were able to attribute an individual HPV type to each area of CIN lesions. We demonstrate that HPV16 is even more etiologically dominant than previously thought, based on various genotype attribution models.

HPV testing and visual inspection for cervical cancer screening in resource-poor regions.

Human papillomavirus (HPV) infection is accepted as the necessary cause of cervical cancer. HPV testing is highly sensitive for high-grade cervical intraepithelial neoplasia (CIN2–3) and cervical cancer but has modest specificity. Visual inspection with acetic acid (VIA) is another possible alternative to cytology for low-resource regions because it is inexpensive requires minimum training and provides rapid results; however VIA alone is not sufficiently accurate. We propose a strategy of HPV testing and immediate VIA among HPV-positive women. HPV testing would provide sensitivity while VIA would triage to treatment only the most severe lesions. This screening strategy would target 25–49-yearold women considering HPV natural history (frequent infections in young women are usually benign) VIA performance (declines with age) and age-specific rates of cervical cancer (rare under 25). (excerpt)

Identification of a novel human papillomavirus (HPV97) related to HPV18 and HPV45

Human papillomavirus (HPV) type 97 was identified and the genome was cloned from cervicovaginal cells of a Costa Rican woman with a normal Pap smear. The HPV97 L1 open reading frame (ORF) was most closely related to HPV45 (84% identity) and HPV18 (79% identity), placing it into the high‐risk α7 species. Ectopic expression of the HPV97 E6 and E7 proteins significantly decreased steady state p53 and pRb levels using an in vitro cotransfection assay, respectively. These data suggest that HPV97 shares a most recent common ancestor with HPV18 and HPV45 and should be evaluated in cancer specimens from different geographic populations.

Evaluation of a multiplex panel of immune-related markers in cervical secretions: a methodologic study.

Although persistent carcinogenic human papillomavirus (HPV) infection is necessary for cervical carcinogenesis, the cofactors involved in HPV persistence and disease progression are poorly understood. Chronic cervical inflammation may increase risk, but few studies have measured immune markers (cytokines, chemokines and soluble receptors) in cervical secretions. We evaluated the performance of 74 multiplexed, bead‐based immune markers in cervical secretions from three groups of women with biopsy evaluation of cervical intraepithelial neoplasia (CIN), (i) 25% detectability and >80% interclass correlation coefficients (ICCs) acceptable for epidemiologic studies. Within‐batch coefficients of variation (CVs) of ≥25% indicated room for assay improvement. Secondarily, we explored associations between marker levels and CIN/HPV status adjusted for matching variables, assay batch, age and number of sexual partners. Sixty‐two markers (84%) had >25% detectability and ICCs > 80%. Of those, 53 (85%) had CVs < 25%. Using these preliminary data, we found that HPV positivity was associated with increased eotaxin‐1 [odds ratio (OR): 15.63, 95% confidence interval (CI): 1.26–200.00] and G‐CSF (OR: 12.99, 95% CI: 1.10–142.86) among CIN‐negative women. There was suggestive evidence that higher chemoattractant marker levels were associated with CIN2/3 (e.g., MIP‐1delta, OR: 4.48, 95% CI: 0.87–23.04 versus

Clinical Outcomes after Conservative Management of Cervical Intraepithelial Neoplasia Grade 2 (CIN2) in Women Ages 21–39 Years

Cervical intraepithelial neoplasia grade 2 (CIN2) frequently regresses, is typically slow-growing, and rarely progresses to cancer. Some women forgo immediate treatment, opting for conservative management (heightened surveillance with cytology and colposcopy), to minimize overtreatment and increased risk of obstetric complications; however, there are limited data examining clinical outcomes in these women. We performed a retrospective cohort analysis of younger women diagnosed with initially untreated CIN1/2, CIN2 and CIN2/3 lesions at Kaiser Permanente Northern California between 2003 and 2015. Clinical outcomes were categorized into five mutually exclusive hierarchical groups: cancer, treated, returned to routine screening, persistent high-grade lesion, or persistent low-grade lesion. Median follow-up for the 2,417 women was 48 months. Six women were diagnosed with cancer (0.2%), all with history of high-grade cytology, and none after a negative cotest. Thirty percent of women were treated, and only 20% returned to routine screening; 50% remained in continued intensive follow-up, of which 86% had either low-grade cytology/histology or high-risk human papillomavirus (HPV) positivity, but not necessarily persistence of a single HPV type. No cancers were detected after a single negative cotest in follow-up. Almost half of initially untreated women did not undergo treatment, but remained by protocol in colposcopy clinic for 2 or more years in the absence of persisting CIN2+. Their incomplete return to total negativity was possibly due to sequential new and unrelated low-grade abnormalities. The prolonged colposcopic surveillance currently required to return to routine screening in the absence of persisting CIN2+ might not be necessary after a negative cotest. Significance: Many younger women under conservative management following an initial CIN2 result remain in a clinical protocol of prolonged intensified surveillance without a subsequent diagnosis of CIN2 or more severe diagnoses. More research is needed to determine whether such prolonged management might be unnecessary following a negative cotest for those women with an initial CIN2 but otherwise only low-grade findings. Cancer Prev Res; 11(3); 165–70. ©2018 AACR.

Risk Assessment Approach to Management

Risk assessment is a process that updates a baseline, prior, or pre-test risk of disease in a certain population to a post-test risk. In cervical cancer screening, risk thresholds determine whether referral to colposcopy or treatment is needed and what time intervals should be chosen for different screening and management options. For example, the risk of cervical cancer and CIN3 in the general population is low. Screening tests like cytology or HPV testing change the prior, baseline risk estimate to a higher risk in test-positive women and to a lower risk in those who are test-negative. Risk stratification is only meaningful when different risk levels result in different clinical practice. For example, HPV testing of ASC-US changes management. HPV testing of HSIL, on the other hand, is not worth doing because colposcopy is indicated regardless of the result. Updating accepted, successful screening and management strategies with new technologies requires a rational framework. The risk scale described in this chapter is universal and independent of the test used. It can serve as a reference that allows making test-independent screening and management recommendations.