Hormuzd A. Katki

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.

Selection Criteria for Lung-Cancer Screening

BACKGROUND The National Lung Screening Trial (NLST) used risk factors for lung cancer (e.g., ≥30 pack-years of smoking and <15 years since quitting) as selection criteria for lung-cancer screening. Use of an accurate model that incorporates additional risk factors to select persons for screening may identify more persons who have lung cancer or in whom lung cancer will develop. METHODS We modified the 2011 lung-cancer risk-prediction model from our Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial to ensure applicability to NLST data; risk was the probability of a diagnosis of lung cancer during the 6-year study period. We developed and validated the model (PLCO(M2012)) with data from the 80,375 persons in the PLCO control and intervention groups who had ever smoked. Discrimination (area under the receiver-operating-characteristic curve [AUC]) and calibration were assessed. In the validation data set, 14,144 of 37,332 persons (37.9%) met NLST criteria. For comparison, 14,144 highest-risk persons were considered positive (eligible for screening) according to PLCO(M2012) criteria. We compared the accuracy of PLCO(M2012) criteria with NLST criteria to detect lung cancer. Cox models were used to evaluate whether the reduction in mortality among 53,202 persons undergoing low-dose computed tomographic screening in the NLST differed according to risk. RESULTS The AUC was 0.803 in the development data set and 0.797 in the validation data set. As compared with NLST criteria, PLCO(M2012) criteria had improved sensitivity (83.0% vs. 71.1%, P<0.001) and positive predictive value (4.0% vs. 3.4%, P=0.01), without loss of specificity (62.9% and. 62.7%, respectively; P=0.54); 41.3% fewer lung cancers were missed. The NLST screening effect did not vary according to PLCO(M2012) risk (P=0.61 for interaction). CONCLUSIONS The use of the PLCO(M2012) model was more sensitive than the NLST criteria for lung-cancer detection.

Targeting of Low-Dose CT Screening According to the Risk of Lung-Cancer Death

BACKGROUND In the National Lung Screening Trial (NLST), screening with low-dose computed tomography (CT) resulted in a 20% reduction in lung-cancer mortality among participants between the ages of 55 and 74 years with a minimum of 30 pack-years of smoking and no more than 15 years since quitting. It is not known whether the benefits and potential harms of such screening vary according to lung-cancer risk. METHODS We assessed the variation in efficacy, the number of false positive results, and the number of lung-cancer deaths prevented among 26,604 participants in the NLST who underwent low-dose CT screening, as compared with the 26,554 participants who underwent chest radiography, according to the quintile of 5-year risk of lung-cancer death (ranging from 0.15 to 0.55% in the lowest-risk group [quintile 1] to more than 2.00% in the highest-risk group [quintile 5]). RESULTS The number of lung-cancer deaths per 10,000 person-years that were prevented in the CT-screening group, as compared with the radiography group, increased according to risk quintile (0.2 in quintile 1, 3.5 in quintile 2, 5.1 in quintile 3, 11.0 in quintile 4, and 12.0 in quintile 5; P=0.01 for trend). Across risk quintiles, there were significant decreasing trends in the number of participants with false positive results per screening-prevented lung-cancer death (1648 in quintile 1, 181 in quintile 2, 147 in quintile 3, 64 in quintile 4, and 65 in quintile 5). The 60% of participants at highest risk for lung-cancer death (quintiles 3 through 5) accounted for 88% of the screening-prevented lung-cancer deaths and for 64% of participants with false positive results. The 20% of participants at lowest risk (quintile 1) accounted for only 1% of prevented lung-cancer deaths. CONCLUSIONS Screening with low-dose CT prevented the greatest number of deaths from lung cancer among participants who were at highest risk and prevented very few deaths among those at lowest risk. These findings provide empirical support for risk-based targeting of smokers for such screening. (Funded by the National Cancer Institute.).

2012 updated consensus guidelines for the management of abnormal cervical cancer screening tests and cancer precursors.

ABSTRACT A group of 47 experts representing 23 professional societies, national and international health organizations, and federal agencies met in Bethesda, MD, September 14–15, 2012, to revise the 2006 American Society for Colposcopy and Cervical Pathology Consensus Guidelines. The group’s goal was to provide revised evidence-based consensus guidelines for managing women with abnormal cervical cancer screening tests, cervical intraepithelial neoplasia (CIN) and adenocarcinoma in situ (AIS) following adoption of cervical cancer screening guidelines incorporating longer screening intervals and co-testing. In addition to literature review, data from almost 1.4 million women in the Kaiser Permanente Northern California Medical Care Plan provided evidence on risk after abnormal tests. Where data were available, guidelines prescribed similar management for women with similar risks for CIN 3, AIS, and cancer. Most prior guidelines were reaffirmed. Examples of updates include: Human papillomavirus–negative atypical squamous cells of undetermined significance results are followed with co-testing at 3 years before return to routine screening and are not sufficient for exiting women from screening at age 65 years; women aged 21–24 years need less invasive management, especially for minor abnormalities; postcolposcopy management strategies incorporate co-testing; endocervical sampling reported as CIN 1 should be managed as CIN 1; unsatisfactory cytology should be repeated in most circumstances, even when HPV results from co-testing are known, while most cases of negative cytology with absent or insufficient endocervical cells or transformation zone component can be managed without intensive follow-up.

Reduced Prevalence of Oral Human Papillomavirus (HPV) 4 Years after Bivalent HPV Vaccination in a Randomized Clinical Trial in Costa Rica

Background Human papillomavirus (HPV) infection, particularly with type 16, causes a growing fraction of oropharyngeal cancers, whose incidence is increasing, mainly in developed countries. In a double-blind controlled trial conducted to investigate vaccine efficacy (VE) of the bivalent HPV 16/18 vaccine against cervical infections and lesions, we estimated VE against prevalent oral HPV infections 4 years after vaccination. Methods and Findings A total of 7,466 women 18–25 years old were randomized (1∶1) to receive the HPV16/18 vaccine or hepatitis A vaccine as control. At the final blinded 4-year study visit, 5,840 participants provided oral specimens (91·9% of eligible women) to evaluate VE against oral infections. Our primary analysis evaluated prevalent oral HPV infection among all vaccinated women with oral and cervical HPV results. Corresponding VE against prevalent cervical HPV16/18 infection was calculated for comparison. Oral prevalence of identifiable mucosal HPV was relatively low (1·7%). Approximately four years after vaccination, there were 15 prevalent HPV16/18 infections in the control group and one in the vaccine group, for an estimated VE of 93·3% (95% CI = 63% to 100%). Corresponding efficacy against prevalent cervical HPV16/18 infection for the same cohort at the same visit was 72·0% (95% CI = 63% to 79%) (p versus oral VE = 0·04). There was no statistically significant protection against other oral HPV infections, though power was limited for these analyses. Conclusions HPV prevalence four years after vaccination with the ASO4-adjuvanted HPV16/18 vaccine was much lower among women in the vaccine arm compared to the control arm, suggesting that the vaccine affords strong protection against oral HPV16/18 infection, with potentially important implications for prevention of increasingly common HPV-associated oropharyngeal cancer. ClinicalTrials.gov, Registry number NCT00128661

Longitudinal Study of Human Papillomavirus Persistence and Cervical Intraepithelial Neoplasia Grade 2/3: Critical Role of Duration of Infection

BACKGROUND The natural history of human papillomavirus (HPV) infections in older women is critical for preventive strategies, including vaccination and screening intervals, but is poorly understood. In a 7-year population-based cohort study in Guanacaste, Costa Rica, we examined whether womens age and the duration of carcinogenic HPV infections influenced subsequent persistence of infection and risk of cervical intraepithelial neoplasia grade 2 (CIN 2) or worse disease. METHODS At enrollment, of the 9466 participants eligible for pelvic examination, 9175 were screened for cervical neoplasia using multiple methods; those with CIN 2 or worse disease were censored and treated. Participants at low risk of CIN 2 or worse (n = 6029) were rescreened at 5-7 years (passively followed), whereas higher-risk participants (n = 2115) and subsets of low-risk women (n = 540) and initially sexually inactive women (n = 410) were rescreened annually or semiannually (actively followed) for up to 7 years. HPV testing was done using a polymerase chain reaction-based method. We determined, by four age groups (18-25, 26-33, 34-41, and > or =42 years), the proportion of prevalent infections (found at baseline) and newly detected infections (first found during follow-up) that persisted at successive 1-year time points and calculated absolute risks of CIN 2 and CIN grade 3 (CIN 3) or worse during follow-up. P values are two-sided. RESULTS Regardless of the womans age, newly detected infections were associated with very low absolute risks of persistence, CIN 2, or worse disease. For newly detected infections, the rate of progression to CIN 2+ (or CIN 3+), after 3 years of follow-up, was not higher for women aged 34 years and older than for younger women. Moreover, rates of newly detected infections declined sharply with age (in the actively followed group, at ages 18-25, 26-33, 34-41, and > or =42 years, rates were 35.9%, 30.6%, 18.1%, and 13.5%, respectively; P < .001). Among prevalent infections, persistent infections among older women (> or =42 years) was higher than that among younger age groups or new infections at any age (P < .01 for comparison of eight groups). Most (66 of 85) CIN 2 or worse detected during follow-up was associated with prevalent infections. Only a small subset (25 of 1128) of prevalent infections persisted throughout follow-up without apparent CIN 2 or worse. CONCLUSIONS The rate of new infections declines with age, and new infections typically do not progress to CIN 2 or worse disease in older women; thus, overall potential benefit of prophylactic vaccination or frequent HPV screening to prevent or detect new carcinogenic HPV infections at older ages is low.

Increased Levels of Circulating Interleukin 6, Interleukin 8, C-Reactive Protein, and Risk of Lung Cancer

BACKGROUND Previous studies that were based primarily on small numbers of patients suggested that certain circulating proinflammatory cytokines may be associated with lung cancer; however, large independent studies are lacking. METHODS Associations between serum interleukin 6 (IL-6) and interleukin 8 (IL-8) levels and lung cancer were analyzed among 270 case patients and 296 control subjects participating in the National Cancer Institute-Maryland (NCI-MD) case-control study. Results were validated in 532 case patients and 595 control subjects in a nested case-control study within the prospective Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. Association with C-reactive protein (CRP), a systemic inflammation biomarker, was also analyzed. Associations between biomarkers and lung cancer were estimated using logistic regression models adjusted for smoking, stage, histology, age, and sex. The 10-year standardized absolute risks of lung cancer were estimated using a weighted Cox regression model. RESULTS Serum IL-6 and IL-8 levels in the highest quartile were associated with lung cancer in the NCI-MD study (IL-6, odds ratio [OR] = 3.29, 95% confidence interval [CI] = 1.88 to 5.77; IL-8, OR = 2.06, 95% CI = 1.19 to 3.57) and with lung cancer risk in the PLCO study (IL-6, OR = 1.48, 95% CI = 1.04 to 2.10; IL-8, OR = 1.57, 95% CI = 1.10 to 2.24), compared with the lowest quartile. In the PLCO study, increased IL-6 levels were only associated with lung cancer diagnosed within 2 years of blood collection, whereas increased IL-8 levels were associated with lung cancer diagnosed more than 2 years after blood collection (OR = 1.57, 95% CI = 1.15 to 2.13). The 10-year standardized absolute risks of lung cancer in the PLCO study were highest among current smokers with high IL-8 and CRP levels (absolute risk = 8.01%, 95% CI = 5.77% to 11.05%). CONCLUSIONS Although increased levels of both serum IL-6 and IL-8 are associated with lung cancer, only IL-8 levels are associated with lung cancer risk several years before diagnosis. Combination of IL-8 and CRP are more robust biomarkers than either marker alone in predicting subsequent lung cancer.

Hematologic and Biochemical Changes Associated with Human T Lymphotropic Virus Type 1 Infection in Jamaica: A Report from the Population-Based Blood Donors Study

Background. A quadrivalent (types 6, 11, 16, and 18) human papillomavirus (HPV) L1 virus-like-particle (VLP) vaccine has been shown to be 95%-100% effective in preventing cervical and genital disease related to HPV-6, -11, -16, and -18 in 16-26-year-old women naive for HPV vaccine types. Because most women in the general population are sexually active, some will have already been infected with ≥ 1 HPV vaccine types at the time vaccination is offered. Here, we assessed whether such infected women are protected against disease caused by the remaining HPV vaccine types. Methods. Two randomized, placebo-controlled trials of the quadrivalent (types 6, 11, 16, and 18) HPV vaccine enrolled 17,622 women without consideration of baseline HPV status. Among women infected with 1-3 HPV vaccine types at enrollment, efficacy against genital disease related to the HPV vaccine type or types for which subjects were naive was assessed. Results. Vaccination was 100% effective (95% confidence interval [Cl], 79%-100%) in preventing incident cervical intraepithelial neoplasia 2 or 3 or cervical adenocarcinoma in situ caused by the HPV type or types for which the women were negative at enrollment. Efficacy for preventing vulvar or vaginal HPV-related lesions was 94% (95% CI,81%-99%). Conclusions. Among women positive for 1-3 HPV vaccine types before vaccination, the quadrivalent HPV vaccine protected against neoplasia caused by the remaining types. These results support vaccination of the general population without prescreening.OBJECTIVE We investigated changes in hematologic and biochemical parameters associated with human T lymphotropic virus type 1 (HTLV-1) infection, antibody titer, and provirus load. Additionally, on a subset of participants, we assessed the epidemiologic relationship of HTLV-1 with Strongyloides stercoralis. METHODS Among volunteer blood donors in Jamaica, HTLV-1 carriers (n=482) were frequency matched with HTLV-1 negative subjects (n=355) by age (+/-5 years), sex, and date of blood donation (+/-3 months). HTLV-1 antibody titer, provirus load, S. stercoralis IgG antibodies, complete blood cell count, blood chemistry, and urinalysis parameters were measured. RESULTS HTLV-1 carriers, compared with HTLV-1-negative individuals, had elevated levels of cleaved lymphocytes (24.5% vs. 16.4%), any lymphocyte abnormalities (atypical, cleaved, and reactive lymphocytes combined, 45.7% vs. 35.4%), and gamma-glutamyl transferase levels (21.2 vs. 19.6 IU/L), as well as lower eosinophil count (2.6% vs. 3.1%). Among carriers, HTLV-1 antibody titer (n=482) was inversely correlated with mean corpuscular volume (r=-0.10) and positively correlated with levels of total protein (r=0.16), phosphorus (r=0.12), and lactate dehydrogenase (r=0.24). HTLV-1-provirus load (n=326) was higher among carriers with cleaved lymphocytes and any lymphocyte abnormalities. Provirus load was inversely correlated with hemoglobin (r=-0.11), mean corpuscular volume (r=-0.15), neutrophil (r=-0.12), and eosinophil (r=-0.19) levels and was positively correlated with lactate dehydrogenase levels (r=0.12). Provirus load was significantly higher among male than female subjects. S. stercoralis antibodies were detected in 35 (12.1%) of 288 participants but were not associated with HTLV-1 status, antibody titer, or provirus load. CONCLUSIONS Markers of HTLV-1 infection (infection status, antibody titer, and provirus load) are associated with hematologic and biochemical alterations, such as lymphocyte abnormalities, anemia, decreased eosinophils, and elevated lactate dehydrogenase levels.

Human papillomavirus infection with multiple types: pattern of coinfection and risk of cervical disease.

OBJECTIVE We investigated coinfection patterns for 25 human papillomavirus (HPV) types and assessed the risk conferred by multiple HPV types toward cervical disease. METHODS Sexually active women (n=5,871) in the NCI-sponsored Costa Rica HPV Vaccine Trials prevaccination enrollment visit were analyzed. Genotyping for 25 HPVs was performed using SPF(10)/LiPA(25). We calculated odds ratios (ORs) to assess coinfection patterns for each genotype with 24 other genotypes. These ORs were pooled and compared with pair-specific ORs to identify genotype combinations that deviated from the pooled OR. We compared risk of CIN2+/HSIL+between multiple and single infections and assessed additive statistical interactions. RESULTS Of the 2478 HPV-positive women, 1070 (43.2%) were infected with multiple types. Multiple infections occurred significantly more frequently than predicted by chance. However, this affinity to be involved in a coinfection (pooled OR for 300 type-type combinations=2.2; 95% confidence interval [CI]=2.1-2.4) was not different across HPV type-type combinations. Compared with single infections, coinfection with multiple α9 species was associated with significantly increased risk of CIN2+(OR=2.2; 95% CI=1.1-4.6) and HSIL+(OR=1.6; 95% CI=1.1-2.4). However, disease risk was similar to the sum of estimated risk from individual types, with little evidence for synergistic interactions. CONCLUSIONS Coinfecting HPV genotypes occur at random and lead to cervical disease independently.

Incidence of Breast Cancer in the United States: Current and Future Trends

BACKGROUND The incidence of breast cancer increased in the United States until circa 2000 then decreased, mostly among women with estrogen receptor (ER)-positive cancers. Time trends provide important clues for cancer etiology and prevention; however, the observed trends of ER-positive and ER-negative breast cancers can be biased by missing ER data. METHODS We developed a simple imputation method to correct invasive female breast cancer incidence for missing or unknown ER expression, using nationally representative data from the National Cancer Institutes Surveillance, Epidemiology, and End Results Program during 1980-2008, including 588,720 invasive female breast cancer patients with 471,336,233 woman-years of follow-up. Corrected rates of ER-positive and ER-negative breast cancers were used to calculate age-standardized incidence rates, estimated annual percentage changes, and projections derived from age-period-cohort models. RESULTS The recent decrease in the incidence of breast cancer overall stabilized near 200 per 100,000 woman-years by 2007-2008, reflecting a transient decrease in ER-positive cancers and a steady decrease in ER-negative cancers. The projected incidence rate for breast cancer overall through the year 2016 was similar to the incidence rate during 2007-2008. In contrast, rates of ER-positive breast cancers were projected to increase 5.3% (95% confidence interval = 5.2% to 5.4%), whereas rates of ER-negative breast cancers were projected to decrease 11.4% (95% confidence interval = 11.3% to 11.6%) during 2009-2016. CONCLUSION Recent changes in breast cancer incidence overall reflect the superimposition of divergent trends in ER-positive and ER-negative cancers. If current trends continue, the incidence of ER-positive breast cancers will increase, the incidence of ER-negative breast cancers will continue to decrease, and the incidence of breast cancer overall will remain similar to its current level.