Thomas Lorey

Cervical cancer risk for women undergoing concurrent testing for human papillomavirus and cervical cytology: a population-based study in routine clinical practice

BACKGROUND Concurrent testing for human papillomavirus (HPV) and cervical cytology (co-testing) is an approved alternative to cytology alone in women aged 30 years and older. We aimed to assess the safety in routine clinical practice of 3-year screening intervals for women testing negative for HPV with normal cytology and to assess if co-testing can identify women at high risk of cervical cancer or cervical intraepithelial neoplasia grade 3 (CIN3) or worse over 5 years. METHODS We assessed the 5-year cumulative incidence, starting in 2003-05, of cervical cancer and CIN3 or worse for 331,818 women aged 30 years and older who enrolled in co-testing at Kaiser Permanente Northern California (Berkeley, CA, USA) and had adequate enrolment co-test results. Follow-up continued until Dec 31, 2009. We defined cumulative incidence to include prevalence at enrolment and incidence after enrolment. Prevalence at enrolment was defined as the ratio of women diagnosed with each outcome on the biopsy visit immediately after their enrolment screening visit to the total enrolled women. At screening visits only HPV test and Pap smear samples were collected, and at biopsy visits colposcopically directed biopsies were taken. To estimate post-enrolment incidence, we used Weibull survival models. FINDINGS In 315,061 women negative by HPV testing, the 5-year cumulative incidence of cancer was 3.8 per 100,000 women per year, slightly higher than for the 306,969 who were both negative by HPV and Pap testing (3.2 per 100,000), and half the cancer risk of the 319,177 who were negative by Pap testing (7.5 per 100,000). 313,465 (99.5%) women negative by HPV testing had either normal cytology or equivocal abnormalities. Abnormal cytology greatly increased cumulative incidence of CIN3 or worse over 5 years for the 16,757 positive by HPV testing (12.1%vs 5.9%; p<0.0001). By contrast, although statistically significant, abnormal cytology did not increase 5-year risk of CIN3 or worse for women negative by HPV testing to a substantial level (0.86%vs 0.16%; p=0.004). 12,208 (73%) of the women positive by HPV testing had no cytological abnormality, and these women had 258 (35%) of 747 CIN3 or adenocarcinoma in situ, [corrected] 25 (29%) of 87 cancers, and 17 (63%) of 27 adenocarcinomas. INTERPRETATION For women aged 30 years and older in routine clinical practice who are negative by co-testing (both HPV and cytology), 3-year screening intervals were safe because a single negative test for HPV was sufficient to reassure against cervical cancer over 5 years. Incorporating HPV testing with cytology also resulted in earlier identification of women at high risk of cervical cancer, especially adenocarcinoma. Testing for HPV without adjunctive cytology might be sufficiently sensitive for primary screening for cervical cancer. FUNDING Intramural Research Program of the US National Cancer Institute/NIH/DHHS, and the American Cancer Society.

Benchmarking CIN 3+ risk as the basis for incorporating HPV and Pap cotesting into cervical screening and management guidelines.

Objective In 2012, the US Preventive Services Task Force (USPSTF) and a consensus of 25 organizations endorsed concurrent cytology and human papillomavirus (HPV) testing (“cotesting”) for cervical cancer screening. Past screening and management guidelines were implicitly based on risks defined by Pap-alone, without consideration of HPV test results. To promote management that is consistent with accepted practice, new guidelines incorporating cotesting should aim to achieve equal management of women at equal risk of cervical intraepithelial neoplasia grade 3 and cancer (CIN 3+). Methods We estimated cumulative 5-year risks of CIN 3+ for 965,360 women aged 30 to 64 years undergoing cotesting at Kaiser Permanente Northern California over 2003 to 2010. We calculated the implicit risk thresholds for Pap-alone and applied them for new management guidance on HPV and Pap cotesting, citing 2 examples: HPV-positive/atypical squamous cells of undetermined significance (ASC-US) and HPV-negative/Pap-negative. We call this guidance process “benchmarking.” Results A low-grade squamous intraepithelial lesion result, for which immediate colposcopy is prescribed, carries a 5-year CIN 3+ risk of 5.2%, suggesting that test results with similar risks should be managed with colposcopy. Similarly, ASC-US (2.6% risk) is managed with a 6- to 12-month follow-up visit and Pap-negative (0.26% risk) is managed with a 3-year follow-up visit. The 5-year CIN 3+ risk among women with HPV-positive/ASC-US was 6.8% (95% confidence interval = 6.2%–7.6%). This is greater than the 5.2% risk implicitly leading to referral for colposcopy, consistent with current management recommendations that women with HPV-positive/ASC-US be referred for immediate colposcopy. The 5-year CIN 3+ risk among women with HPV-negative/Pap-negative results was 0.08% (95% confidence interval = 0.07%–0.09%), far below the 0.26% implicitly required for a 3-year return and justifying a longer (e.g., 5-year) return. Conclusions Using the principle of “equal management of equal risks,” benchmarking to implicit risk thresholds based on Pap-alone can be used to achieve safe and consistent incorporation of cotesting.

Five-Year Experience of Human Papillomavirus DNA and Papanicolaou Test Cotesting

OBJECTIVE: To estimate the 5-year age group–specific test positives for Pap tests and human papillomavirus (HPV) testing in a large, general screening population of women 30 and older. METHODS: Using data from Kaiser Permanente Northern California, a large health maintenance organization that introduced cotesting in 2003, we evaluated the cotesting results overall and by 5-year age groups. Women (n=580,289) who opted for and underwent cotesting (n cotests=812,598) between January 2003 and April 2008 were included in the analysis. Pap tests interpreted as atypical squamous cells of undetermined significance (ASC-US) or more severe were considered to be positive. Women were tested for carcinogenic HPV using an assay approved by the U.S. Food and Drug Administration. Binomial exact 95% confidence intervals (CIs) were calculated. RESULTS: Overall, 6.27% (95% CI 6.21–6.32%) of cotests were carcinogenic HPV positive, and only 3.99% (95% CI 3.94–4.03%) cotests had normal cytology and were carcinogenic HPV positive. By comparison, 5.18% (95% CI 5.13–5.23%) of cotests had ASC-US or more severe cytology, and 2.87% (95% CI 2.84–2.91%) of cotests had ASC-US or more severe cytology and were carcinogenic HPV negative. CONCLUSION: In a general screening population, concerns about excessive HPV test positives among women aged 30 years and older are not borne out. LEVEL OF EVIDENCE: III

The age-specific relationships of abnormal cytology and human papillomavirus DNA results to the risk of cervical precancer and cancer.

BACKGROUND: To estimate the relationship of human papillomavirus (HPV) detection and abnormal cytology with histologic diagnoses of cervical precancer and cancer. METHODS: From 2003 to 2008 we examined the HPV, cytology, and diagnostic results from almost one million cervical cancer screenings done on women aged 30 and older who were members in Kaiser Permanente Northern California, a large health maintenance organization that introduced cotesting in 2003. Women were screened using conventional Pap tests and a DNA test for a pool of 13 high-risk HPV genotypes. Women with HPV-positive atypical squamous cells of undetermined significance and other abnormal cervical cytology, independent of their HPV results, routinely underwent colposcopy. Results were stratified by 5-year age groups from 30 to 64. RESULTS: High-grade squamous intraepithelial lesions (HSIL), atypical squamous cells, cannot exclude HSIL (ASC-H), and atypical glandular cells were more strongly associated with cervical intraepithelial neoplasia grade 3 while low-grade squamous intraepithelial lesions (LSIL) and HPV-positive atypical squamous cells of undetermined significance were more strongly associated with cervical intraepithelial neoplasia grade 2 (CIN2). Cervical cancer was most commonly found in women with HSIL and atypical glandular cells cytology. Human papillomavirus–negative women with ASC-H cytology were at a reduced but significant risk of CIN2 or more severe (CIN2+) (10.6%) compared with HPV-positive women with ASC-H cytology. Human papillomavirus–negative women with LSIL were at a 4.0% risk of CIN2+, and among women 50 and older, at a 0.5% risk of CIN2+ with no cancers were diagnosed. CONCLUSION: Human papillomavirus testing may be useful for triage for colposcopic referral for LSIL cytology in older women but not for ASC-H cytology at any age. LEVEL OF EVIDENCE: II

Relationship of Atypical Glandular Cell Cytology, Age, and Human Papillomavirus Detection to Cervical and Endometrial Cancer Risks

OBJECTIVE: To quantify the age-specific and reproductive organ-specific cancer risk after an atypical glandular cell (AGC) cytologic interpretation in large clinic-based sample in which routine high-risk human papillomavirus (HPV) testing is conducted. METHODS: To estimate the absolute risk of cervical precancer, cervical cancer, and endometrial cancer in women with AGC cytology, we conducted a cross-sectional study of women with AGC cytology (n=1,422) in a large health maintenance organization that introduced high-risk HPV DNA testing into cervical cancer screening in 2003. Risks and binomial exact 95% confidence intervals (CIs) of cervical intraepithelial neoplasia grade 2 or more severe (CIN 2 or worse) and endometrial cancer were calculated. RESULTS: A total of 238 women with AGC cytology (16.7%, 95% CI 14.8-18.8%) were diagnosed with CIN 2 or worse, endometrial cancer, or other cancers. Among women aged 50 years or older, 420 high-risk HPV-negative women were at a 10.5% (95% CI 7.7-13.8%) risk of endometrial cancer, and 77 high-risk HPV-positive women were at a 10.4% (95% CI 4.6-19.4%) risk of cervical cancer and 0% (95% CI 0.0-4.7%) risk of endometrial cancer. CONCLUSION: High-risk HPV testing may distinguish between risk of endometrial cancer and cervical cancer in women with AGC cervical cytology, particularly in women aged 50 years or older. LEVEL OF EVIDENCE: III

Five-year risks of CIN 3+ and cervical cancer among women who test Pap-negative but are HPV-positive.

Objective Current US guidelines for cotesting recommend that the large numbers of women who test Pap-negative, but human papillomavirus (HPV)–positive, return in 1 year, and those who remain HPV-positive or have low-grade squamous intraepithelial lesion (LSIL) or worse Pap results be referred for colposcopy. However, the performance of these guidelines in routine clinical practice has not been evaluated. Methods We estimated cumulative 5-year risks of cervical intraepithelial neoplasia grade 3 or worse (CIN 3+) among 32,374 women aged 30 to 64 years with HPV-positive/Pap-negative cotest results at Kaiser Permanente Northern California during 2003 to 2010. Results The 5-year CIN 3+ risk after an HPV-positive/Pap-negative cotest result, which was found in 3.6% of women, was 4.5% (95% confidence interval [CI] = 4.2%–4.8%). The 5-year cancer risk was 0.34% (95% CI = 0.26%–0.45%), and half of the cases were adenocarcinoma. Overall, 48% of the women remained HPV-positive on return (median = 418 days after baseline), a percentage that varied little over ages 30 to 64 years. At the return after a baseline HPV-positive/Pap-negative result, almost every repeat cotest result predicted greater subsequent 5-year CIN 3+ risk than the same cotest result had at baseline (HPV-positive/LSIL, 9.2% vs 6.1%, p = .01; HPV-positive/atypical squamous cells of undetermined significance [ASC-US], 7.9% vs 6.8%, p = .2; HPV-positive/Pap-negative, 7.4% vs 4.5%, p < .0001; HPV-negative/LSIL,1.7% vs 2.0%, p = .8; HPV-negative/ASC-US, 2.9% vs 0.43%, p = .0005; HPV-negative/Pap-negative, 0.93% vs 0.08%, p < .0001). Conclusions Using the principle of “equal management of equal risks,” women testing HPV-positive/Pap-negative had a subsequent CIN 3+ risk consistent with risk thresholds for a 1-year return. However, on returning in approximately 1 year, about one-half of women will be referred for colposcopy because of continued HPV positivity or Pap abnormality. Clinicians should keep in mind that cotest results at the return after a baseline HPV-positive/Pap-negative finding are riskier than the same baseline cotest results in the general population, supporting intensified clinical management at return testing.

Five-year risks of CIN 3+ and cervical cancer among women with HPV testing of ASC-US Pap results.

Objective New screening guidelines recommend that human papillomavirus (HPV)–negative/atypical squamous cells of undetermined significance (ASC-US) results be considered as equivalent to HPV-negative/Pap-negative results, leading to rescreening in 5 years. However, despite ample data, the routine clinical performance of HPV testing of women with ASC-US has not been adequately documented. Methods We estimated 5-year risks of cervical intraepithelial neoplasia (CIN) 3+ and of cancer among 2 groups of women between 2003 and 2010 at Kaiser Permanente Northern California: 27,050 aged 30 to 64 years who underwent HPV and Pap cotesting and had an ASC-US Pap result and 12,209 aged 25 to 29 years who underwent HPV triage of ASC-US. Results Five-year risks of CIN 3+ and of cancer among women aged 30 to 64 years testing HPV-negative/ASC-US and among 923,152 women testing Pap-negative alone were similar although statistically distinguishable (CIN 3+, 0.43% vs 0.26%, p = .001; cancer, 0.050% vs 0.025%, p = .1). The increased risk of cancer after HPV-negative/ASC-US versus Pap-negative alone was confined to women aged 60 to 64 years (0.26% vs 0.035%, p = .3). Five-year risks of CIN 3+ and cancer among women with HPV-negative/ASC-US results were substantially higher than those among women testing HPV-negative/Pap-negative (CIN 3+, 0.43% vs 0.08%, p < .0001; cancer, 0.050% vs 0.011%, p = .003). For women aged 30 to 64 years testing HPV-positive/ASC-US, 5-year risks of CIN 3+ and cancer were slightly higher than those among 9,374 women with low-grade squamous intraepithelial lesion (LSIL) (CIN 3+, 6.8% vs 5.2%, p = .0007; cancer, 0.41% vs 0.16%, p = .04). Similar patterns were seen for women aged 25 to 29 years. Conclusions Women with HPV-negative/ASC-US had a similar risk as women testing Pap-negative alone but had a higher risk than women testing HPV-negative/Pap-negative. Based upon the principle of “equal management of equal risks,” our findings support the equal management of women with HPV-negative/ASC-US and those with Pap-negative alone, except for exiting women from screening because cancer risks at ages 60 to 64 years may be higher for women testing HPV-negative/ASC-US. Our findings also support managing HPV-positive/ASC-US and LSIL similarly.

Human Papillomavirus Genotype Attribution and Estimation of Preventable Fraction of Anal Intraepithelial Neoplasia Cases Among HIV-Infected Men Who Have Sex With Men

BACKGROUND The prevention of human papillomavirus (HPV)-induced anal cancer in high-risk populations such as human immunodeficiency virus (HIV)-infected men who have sex with men (MSM) remains an urgent priority, given rising incidence rates despite widespread antiretroviral therapy use. METHODS HPV genotypes and anal disease prevalence, by cytology and histopathologic findings, were evaluated among 363 HIV-infected MSM. We modeled fractions of high-grade anal intraepithelial neoplasia (HGAIN) attributable to individual carcinogenic HPV genotypes and estimated the range of the proportion of HGAIN cases potentially preventable by prophylactic HPV vaccines. RESULTS HPV16 was the most common genotype overall (26.4% of cases) and among HGAIN cases (55%). Prevalence of multiple (≥ 2) carcinogenic HPV genotypes increased from 30.9% in cases of AIN grade <1 to 76.3% in cases of AIN grade 3 (P(trend) < .001). The fractions of HGAIN cases attributable to carcinogenic HPV16/18 targeted by currently licensed bivalent and quadrivalent HPV vaccines ranged from 12% to 61.5%, and the fractions attributable to carcinogenic HPV16/18/31/33/45/52/58 targeted by an investigational nonavalent HPV vaccine ranged from 39% to 89.4%. CONCLUSIONS Our analytical framework allows estimation of HGAIN cases attributable to individual HPV genotypes in the context of multiple concurrent HPV infections, which are very common among HIV-infected MSM. Our results suggest that licensed and investigational HPV prophylactic vaccines have the potential to prevent a substantial proportion of HGAIN cases in this population.

Five-year risk of recurrence after treatment of CIN 2, CIN 3, or AIS: performance of HPV and Pap cotesting in posttreatment management.

Objective After excisional treatment, cervical intraepithelial neoplasia grade 2 or worse (CIN 2+) can recur. It is not clear how many negative posttreatment Pap or cotest results are needed to ensure adequate safety against CIN 2+ before returning to extended retesting intervals. Methods We observed 5-year risks of CIN 2+ for 3 follow-up management strategies after treatment (Pap-alone, human papillomavirus [HPV]-alone, and HPV/Pap cotesting) for 3,273 women aged 25 years and older who were treated for CIN 2, CIN 3, or adenocarcinoma in situ (AIS) between 2003 and 2010 at Kaiser Permanente Northern California. Results Five-year risks of recurrent CIN 2+ after treatment varied both by antecedent screening test result and the histology of the treated lesion. The risk ranged from 5% for CIN 2 preceded by HPV-positive/atypical squamous cells of undetermined significance or low-grade squamous intraepithelial lesion to 16% for CIN 3/AIS preceded by atypical glandular cells (AGC)/atypical squamous cells cannot rule out high-grade squamous intraepithelial lesion (ASC-H)/high-grade squamous intraepithelial lesion or worse (HSIL+) (p < .0001). However, after posttreatment negative tests, risks were lowered and similar regardless of antecedent screening test and histology of treated disease. The 5-year recurrent CIN 2+ risk after a negative posttreatment cotest (2.4%) was lower than that following a negative HPV test (3.7%, p = .3) or negative Pap result (4.2%, p = .1). Two negative posttreatment tests of each kind conferred slightly lower 5-year CIN 2+ risk than one (2 negative Pap tests vs. 1, 2.7% vs 4.2%, p = .2; 2 negative HPV tests vs. 1, 2.7% vs 3.7%, p = .7; 2 negative cotests vs. 1, 1.5% vs 2.4%, p = .8). The 5-year CIN 2+ risk after 2 negative cotests of 1.5% (95% confidence interval = 0.3%–7.2%) approached the 0.68% risk after a negative Pap test during routine screening. Conclusions Women with antecedent AGC/ASC-H/HSIL+ Pap results or those treated for CIN 3/AIS had a substantial risk of developing CIN 2+ posttreatment. On the basis of the principle of “equal management of equal risks,” after negative test results posttreatment, no subgroup of women achieved risk sufficiently low to return to 5-year routine screening. However, negative cotests after treatment provided more reassurance against recurrent CIN 2+ than either negative Pap tests or HPV tests alone.

HPV16 Sublineage Associations With Histology-Specific Cancer Risk Using HPV Whole-Genome Sequences in 3200 Women

BACKGROUND HPV16 is a common sexually transmitted infection although few infections lead to cervical precancer/cancer; we cannot distinguish nor mechanistically explain why only certain infections progress. HPV16 can be classified into four main evolutionary-derived variant lineages (A, B, C, D) that have been previously suggested to have varying disease risks. METHODS We used a high-throughput HPV16 whole-genome sequencing assay to investigate variant lineage risk among 3215 HPV16-infected women. Using sublineages A1/A2 as the reference, we assessed all variant lineage associations with infection outcome over three or more years of follow-up: 1107 control subjects (<CIN2), 906 CIN2, 1008 CIN3, 69 squamous cell carcinomas (SCC), 85 adenocarcinomas in situ (AIS), and 40 adenocarcinomas. Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). All statistical tests were two-sided. RESULTS A4 sublineage was associated with an increased risk of cancer, specifically adenocarcinoma (OR = 9.81, 95% CI = 2.02 to 47.69, P = 4.7x10(-03)). Lineage B had a lower risk of CIN3 (OR = 0.51, 95% CI = 0. 28 to 0.91, P = 02) while lineage C showed increased risk (OR = 2.06, 95% CI = 1.09 to 3.89, P = 03). D2/D3 sublineages were strongly associated with an increased risk of CIN3 and cancer, particularly D2 (OR for cancer = 28.48, 95% CI = 9.27 to 87.55, P = 5.0x10(-09)). D2 had the strongest increased risk of glandular lesions, AIS (OR = 29.22, 95% CI = 8.94 to 95.51, P = 2.3x10(-08)), and adenocarcinomas (OR = 137.34, 95% CI = 37.21 to 506.88, P = 1.5x10(-13)). Moreover, the risk of precancer and cancer for specific variant lineages varied by a womens race/ethnicity; those women whose race/ethnicity matched that of the infecting HPV16 variant had an increased risk of CIN3 + (P < 001). CONCLUSIONS Specific HPV16 variant sublineages strongly influence risk of histologic types of precancer and cancer, and viral genetic variation may help explain its unique carcinogenic properties.