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As the primary screening test, E6/E7 mRNA has shown similar sensitivity for CIN3+ and lower positivity rate than the HPV DNA test. Nevertheless, the overall mRNA positivity is too high for immediate colposcopy, making a triage test necessary. The aim was to estimate the mRNA performance as a primary test with different triage strategies. All HPV DNA-positives were tested for mRNA, cytology and p16/ki67. A sample of HPV DNA-negatives was also tested for mRNA to estimate test specificity. We included all CIN3+ histologically diagnosed within 24 months since recruitment. Of the 41 127 participants, 7.7% were HPV DNA-positive, of which 66.4% were mRNA-positive. Among the HPV DNA-negatives, 10/1108 (0.9%) were mRNA-positive. Overall, 97 CIN3+ were found. If mRNA was used as the primary test, it would miss about 3% of all CIN3+ with a 22% reduction of positivity compared with HPV DNA. The weighted specificity estimate for

Birth cohorts vaccinated against human papillomavirus (HPV) are now entering cervical cancer screening. Assessment of (pre)cancer (CIN3+) risk is needed to assess the residual screening need in vaccinated women. We estimated the lifetime (screen-detected) CIN3+ risk under five-yearly primary HPV screening between age 30 and 60, using HPV genotyping and histology data of 21,287 women participating in a screening trial with two HPV-based screening rounds, 5 years apart. The maximum follow-up after an HPV-positive test was 9 years. We re-estimated the CIN3+ risk after projecting direct vaccine efficacy for the bivalent and the nonavalent HPV vaccines, assuming life-long protection. The lifetime CIN3+ risk was 4.1% (95% confidence interval 3.5-4.9) and declined by 53.5% and 70.5% after bivalent vaccination without and with cross-protection, respectively, translating into a residual lifetime CIN3+ risk of 1.9% (1.4-2.4) and 1.2% (0.9-1.5). The CIN3+ risk declined by 88.5% after nonavalent vaccination, translating into a residual lifetime CIN3+ risk of 0.5% (0.2-0.7). The latter risk increased to 1.6% when vaccine protection only lasted until the first screening round at age 30. Among HPV-positive women with abnormal adjunct cytology, the nine-year CIN3+ risk was 16.9% (8.7-32.4) after nonavalent vaccination. In conclusion, HPV vaccination will lead to a strong decline in the lifetime CIN3+ risk and the remaining absolute CIN3+ risk will be very low. Primary HPV testing combined with adjunct cytology at five-year intervals still seems feasible even after nonavalent vaccination, although unlikely to be cost-effective. Our results support a de-intensification of screening programs in settings with high vaccination coverage., (© 2020 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of Union for International Cancer Control.)

Human papillomavirus (HPV) testing is very sensitive for primary cervical screening but has low specificity. Triage tests that improve specificity but maintain high sensitivity are needed. Women enrolled in the experimental arm of Phase 2 of the New Technologies for Cervical Cancer randomized controlled cervical screening trial were tested for high-risk HPV (hrHPV) and referred to colposcopy if positive. hrHPV-positive women also had HPV genotyping (by polymerase chain reaction with GP5+/GP6+ primers and reverse line blotting), immunostaining for p16 overexpression and cytology. We computed sensitivity, specificity and positive predictive value (PPV) for different combinations of tests and determined potential hierarchical ordering of triage tests. A number of 1,091 HPV-positive women had valid tests for cytology, p16 and genotyping. Ninety-two of them had cervical intraepithelial neoplasia grade 2+ (CIN2+) histology and 40 of them had CIN grade 3+ (CIN3+) histology. The PPV for CIN2+ was >10% in hrHPV-positive women with positive high-grade squamous intraepithelial lesion (61.3%), positive low-grade squamous intraepithelial lesion (LSIL+) (18.3%) and positive atypical squamous cells of undetermined significance (14.8%) cytology, p16 positive (16.7%) and, hierarchically, for infections by HPV33, 16, 35, 59, 31 and 52 (in decreasing order). Referral of women positive for either p16 or LSIL+ cytology had 97.8% sensitivity for CIN2+ and women negative for both of these had a 3-year CIN3+ risk of 0.2%. Similar results were seen for women being either p16 or HPV16/33 positive. hrHPV-positive women who were negative for p16 and cytology (LSIL threshold) had a very low CIN3+ rate in the following 3 years. Recalling them after that interval and referring those positive for either test to immediate colposcopy seem to be an efficient triage strategy. The same applies to p16 and HPV16., (© 2020 UICC.)

Comparable performance indicators for breast cancer screening in the European Union (EU) have not been previously reported. We estimated adjusted breast cancer screening positivity rate (PR) and detection rates (DR) to investigate variation across EU countries. For the age 50-69 years, the adjusted EU-pooled PR for initial screening was 8.9% (cross-programme variation range 3.2-19.5%) while DR of invasive cancers was 5.3/1,000 (range 3.8-7.4/1,000) and DR of ductal carcinoma in situ (DCIS) was 1.3/1,000 (range 0.7-2.7/1,000). For subsequent screening, the adjusted EU-pooled PR was 3.6% (range 1.4-8.4%), the DR was 4.0/1,000 (range 2.2-5.8/1,000) and 0.8/1,000 (range 0.5-1.3/1,000) for invasive and DCIS, respectively. Adjusted performance indicators showed remarkable heterogeneity, likely due to different background breast cancer risk and awareness between target populations, and also different screening protocols and organisation. Periodic reporting of the screening indicators permits comparison and evaluation of the screening activities between and within countries aiming to improve the quality and the outcomes of screening programmes. Cancer Screening Registries would be a milestone in this direction and EU Screening Reports provide a fundamental contribution to building them., (© 2020 UICC.)

The 2003 European Council recommendation urging the Member States to introduce or scale up breast, cervical and colorectal cancer screening through an organized population-based approach has had a remarkable impact. We argue that the recommendation needs to be updated for at least two sets of reasons. First, some of the current clinical guidelines include new tests or protocols that were not available at the time of the Council document. Some have already been adopted by organized screening programs, such as newly defined age ranges for mammography screening, Human Papillomavirus (HPV)-based cervical cancer screening, fecal immunochemical test (FIT) and sigmoidoscopy for colorectal cancer screening. Second, the outcomes of randomized trials evaluating screening for lung and prostate cancer have been published recently and the balance between harms and benefits needs to be pragmatically assessed. In the European Union, research collaboration and networking to exchange and develop best practices should be regularly supported by the European Commission. Integration between primary and secondary preventive strategies through comprehensive approaches is necessary not only to maximize the reduction in cancer burden but also to control the rising trend of other noncommunicable diseases sharing the same risk factors., (© 2020 International Agency for Research on Cancer (IARC/WHO); licensed by UICC.)

International variations in the prevalence of HPV infection derive from differences in sexual behaviors, which are also a key factor of the basic reproductive number (R 0 ) of HPV infection in different populations. R 0 affects the strength of herd protection and hence the impact of a vaccination program. Similar vaccination programs may therefore generate different levels of impact depending upon the population's pre-vaccination HPV prevalence. We used IARC's transmission model to estimate (i) the overall effectiveness of vaccination versus no vaccination in women aged 15-34 years measured as percent prevalence reduction (%PR) of HPV16 and (ii) the corresponding herd protection in populations with gender-equal or traditional sexual behavior and with different levels of sexual activity, corresponding to pre-vaccination HPV16 prevalence from 1 to 8% as observed worldwide. Between populations with different levels of gender-equal sexual activity, the highest difference in %PR under girls-only vaccination is observed at 40% coverage (91%PR vs. 48%PR for 1% and 8% pre-vaccination prevalence, respectively). HPV16 elimination is obtained with 55 and 97% coverage, respectively. To achieve desirable levels of HPV16 prevalence after vaccination, different levels of coverage are required in populations with different levels of pre-vaccination HPV16 prevalence, for example, in populations with gender-equal sexual behavior a decrease to 1/1000 HPV16 from pre-vaccination prevalence of 1 and 8% would require coverages of 37 and 96%, respectively. In traditional populations, corresponding coverages would need to be 28 and 93%, respectively. In conclusion, pre-vaccination HPV prevalence strongly influences herd immunity and helps predict the overall effectiveness of HPV vaccination., (© 2018 International Agency for Research on Cancer (IARC/WHO); licensed by UICC.)

Cervical cancer screening will rely, increasingly, on HPV testing as a primary screen. The requirement for triage tests which can delineate clinically significant infection is thus prescient. In this EUROGIN 2017 roadmap, justification behind the most evidenced triages is outlined, as are challenges for implementation. Cytology is the triage with the most follow-up data; the existence of an HR-HPV-positive, cytology-negative group presents a challenge and retesting intervals for this group (and choice of retest) require careful consideration. Furthermore, cytology relies on subjective skills and while adjunctive dual-staining with p16/Ki67 can mitigate inter-operator/-site disparities, clinician-taken samples are required. Comparatively, genotyping and methylation markers are objective and are applicable to self-taken samples, offering logistical advantages including in low and middle income settings. However, genotyping may have diminishing returns in immunised populations and type(s) included must balance absolute risk for disease to avoid low specificity. While viral and cellular methylation markers show promise, more prospective data are needed in addition to refinements in automation. Looking forward, systems that detect multiple targets concurrently such as next generation sequencing platforms will inform the development of triage tools. Additionally, multistep triage strategies may be beneficial provided they do not create complex, unmanageable pathways. Inevitably, the balance of risk to cost(s) will be key in decision making, although defining an acceptable risk will likely differ between settings. Finally, given the significant changes to cervical screening and the variety of triage strategies, appropriate education of both health care providers and the public is essential., (© 2018 UICC.)

Human papilloma virus (HPV) testing is more sensitive but less specific than cytology. We evaluated stand-alone genotyping as a possible triage method. During a multicentre randomised controlled trial comparing HPV testing to conventional cytology, HPV-positive women were referred to colposcopy and followed up if no high-grade lesion was detected. HPV-positive samples were genotyped by GP5+/GP6+ primed polymerase chain reaction followed by reverse line blot. Genotypes were hierarchically ordered by positive predictive value (PPV) for CIN grade 2 or more (CIN2+), and grouped by cluster analysis into three groups (A, B and C in decreasing order). Receiver operating characteristic curves were computed. Among 2,255 HPV-positive women with genotyping, 239 CIN2+ (including 113 CIN3+) were detected at baseline or during a 3-year follow-up. HPV33 had the highest PPV with CIN2+ and CIN3+ as the endpoint and when considering lesions detected at baseline or also during follow-up. HPV16 and HPV35 were the second and third, respectively. Cross-sectional sensitivity for CIN2+ at baseline was 67.3% (95% CI 59.7-74.2), 91.8% (95% CI 86.6-95.5) and 94.7% (95% CI 90.2-97.6), respectively, when considering as "positive" any of the HPV types in group A (33, 16 and 35), A or B (31, 52, 18, 59 and 58) and A or B or C (39, 51, 56, 45 and 68). The corresponding cross-sectional PPVs for CIN2+ were 15.8% 95% (CI 13.2-18.7), 12.0% (95% CI 10.3-13.9) and 9.6% (95% CI 8.2-11.1), respectively. HPV33, 16 and 35 confer a high probability of CIN2+ but this rapidly decreases when adding other genotypes., (© 2018 The Authors International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

The second report on the implementation status of cancer screening in European Union (EU) was published in 2017. The report described the implementation status, protocols and organization (updated till 2016) and invitation coverage (for index year 2013) of breast, cervical and colorectal cancer screening in the EU. Experts in screening programme monitoring (N = 80) from the EU Member States having access to requisite information in their respective countries provided data on breast, cervical and colorectal cancer screening through online questionnaires. Data was collected for screening performed in the framework of publicly mandated programmes only. Filled in questionnaires were received from 26 Member States for all three sites and from one Member State for breast cancer only. Substantial improvement in screening implementation using population-based approach was documented. Among the age-eligible women, 94.7% were residents of Member States implementing or planning population-based breast cancer screening in 2016, compared to 91.6% in 2007. The corresponding figures for cervical cancer screening were 72.3 and 51.3% in 2016 and 2007, respectively. Most significant improvement was documented for colorectal cancer screening with roll-out ongoing or completed in 17 Member States in 2016, compared to only five in 2007. So the access to population-based screening increased to 72.4% of the age-eligible populations in 2016 as opposed to only 42.6% in 2007. The invitation coverage was highly variable, ranging from 0.2-111% for breast cancer, 7.6-105% for cervical cancer and 1.8-127% for colorectal cancer in the target populations. In spite of the considerable progress, much work remains to be done to achieve optimal effectiveness. Continued monitoring, regular feedbacks and periodic reporting are needed to ensure the desired impacts of the programmes., (© 2017 UICC.)

Cervical cancer screening test performance has been hampered by either lack of sensitivity of Pap cytology or lack of specificity of Human Papillomavirus (HPV) testing. This uncertainty can lead to unnecessary referral and treatment, which is disturbing for patients and increases costs for health care providers. The identification of p16(INK4a) as a marker for neoplastic transformation of cervical squamous epithelial cells by HPVs allows the identification of HPV-transformed cells in histopathology or cytopathology specimens. Diagnostic studies have demonstrated that the use of p16(INK4a) immunohistochemistry substantially improves the reproducibility and diagnostic accuracy of histopathologic diagnoses. p16(INK4a) cytology has substantially higher sensitivity for detection of cervical precancer in comparison to conventional Pap tests. Compared to HPV DNA tests, immunochemical detection of p16(INK4a) -stained cells demonstrates a significantly improved specificity with remarkably good sensitivity. About 15 years after the initial observation that p16(INK4a) is overexpressed in HPV-transformed cells we review the accumulated clinical evidence suggesting that p16(INK4a) can serve as a useful biomarker in the routine diagnostic work up of patients with HPV infections and associated lesions of the female anogenital tract., (© 2014 The Authors. Published by Wiley Periodicals, Inc. on behalf of UICC.)

Human papillomavirus (HPV) vaccination of a birth cohort of girls in the 9-13 age range is recommended as a priority, but decreases in HPV vaccine cost may make catch-up of a few additional cohorts more attractive not only in high-income countries. We assessed the reduction in HPV16 and 18 infections that could be achieved in a medium- (Poland) and a low-income (Guinea) country by adding one-time catch-up of 12- to 19-year-old girls to the vaccination of 11-year-old girls. According to our ad hoc adapted dynamic model of HPV infection transmission, the addition of catch-up was estimated to bring forward the 50% reduction of HPV16/18 prevalence due to vaccination in women ≤35 by as much as 5 years. Catch-up of 12- to 15-year olds reduced the cumulative probability of HPV16/18 infections by age 35 in the relevant cohorts by about 30% in both countries. Catch-up of 16- to 19-year-old girls added little. Regardless of the chosen catch-up strategy, 16 to 20% of HPV16/18 prevention from vaccination was attributable to herd immunity. Assuming a sufficiently low vaccine cost, the addition of a catch-up round is, therefore, worth considering in medium/low-income countries to extend vaccine benefits to less young adolescent girls whose future access to cervical screening is uncertain., (Copyright © 2013 UICC.)

The EUROGIN 2011 roadmap reviews the current burden of human papillomavirus (HPV)-related morbidity, as well as the evidence and potential practice recommendations regarding primary and secondary prevention and treatment of cancers and other disease associated with HPV infection. HPV infection causes ~600,000 cases of cancer of the cervix, vulva, vagina, anus and oropharynx annually, as well as benign diseases such as genital warts and recurrent respiratory papillomatosis. Whereas the incidence of cervical cancer has been decreasing over recent decades, the incidence of anal and oropharyngeal carcinoma, for which there are no effective screening programs, has been rising over the last couple of decades. Randomized trials have demonstrated improved efficacy of HPV-based compared to cytology-based cervical cancer screening. Defining the best algorithms to triage HPV-positive women, age ranges and screening intervals are priorities for pooled analyses and further research, whereas feasibility questions can be addressed through screening programs. HPV vaccination will reduce the burden of cervical precancer and probably also of invasive cervical and other HPV-related disease in women. Recent trials demonstrated that prophylactic vaccination also protects against anogenital HPV infection, anogenital intraepithelial lesions and warts associated with vaccine types, in males; and anal HPV infection and anal intraepithelial neoplasia in MSM. HPV-related oropharyngeal cancer could be treated less aggressively because of better survival compared to cancers of the oropharynx unrelated to HPV. Key findings in the field of cervical cancer prevention should now be translated in cost-effective strategies, following an organized approach integrating primary and secondary prevention, according to scientific evidence but adapted to the local situation with particular attention to regions with the highest burden of disease., (Copyright © 2012 UICC.)

Concern was raised on using testing for high-risk (HR) human papillomavirus (HPV) in cervical cancer screening in populations where HPV prevalence is high. The impact of HR HPV prevalence on the efficiency of HPV test-based screening has never been directly evaluated. A meta-regression of the relationship between HR HPV prevalence and the specificity and positive predictive value (PPV) of HPV DNA testing for the presence of cervical intraepithelial neoplasia grade 2 or worse (CIN2+) was performed. Only studies that used Hybrid Capture 2 (HC2) were included. Country income (low-medium vs. high) was used as a proxy of previous screening. Twenty-six populations from 20 studies were included. For a 10% increase in HR HPV prevalence, HC2 specificity decreased by 8.41% [95% confidence interval (CI): 8.02-8.81], whereas PPV increased by 4.74% (95% CI: 2.45-7.03). HR HPV prevalence explained 98% of the variability in HC2 specificity and 38% of the variability in PPV. Country income did not affect specificity, but low-medium income was associated with higher PPV (3.81%; 95% CI: 1.53-6.10) after adjustment for HR HPV prevalence. When HR HPV prevalence is high, the specificity of HPV testing for CIN2+ decreases, but PPV does not decrease and it is high in inadequately screened populations. The number of HPV-positive women needing further assessment or treatment per CIN2+ case detected will therefore decrease and screening efficiency will improve. This is explained by the fact that HR HPV causes CIN2+: an increase in HR HPV prevalence is inevitably accompanied by an increase in CIN2+., (Copyright © 2011 UICC.)

The EUROGIN 2010 roadmap represents a continuing effort to provide and interpret updated information on cervical cancer screening and vaccination against the cause of the disease, high-risk human papillomavirus (HPV). Contrary to the two previous reports in 2008 and 2009, the present roadmap gives equal room to HPV-based screening and HPV vaccination, as a result of the recent strengthening of the evidence on the efficacy and feasibility of both approaches. The superiority of HPV testing in primary screening compared to cytology (in more developed countries) and to cytology or visual inspection methods (in less developed countries) has been demonstrated in several randomised trials. High vaccine efficacy has been confirmed up to 7 years after vaccination; school-based programmes in some countries have been able to reach over 70% coverage among adolescent girls. Demonstration projects have indicated that the delivery of HPV vaccines in less developed countries is feasible and favourably received by populations where cervical cancer is very common. HPV-based screening can diminish cervical cancer incidence more quickly than HPV vaccination, but vaccination can eventually facilitate screening efforts, especially if new vaccines against a greater number of HPV types are introduced. The availability of two highly complementary prevention tools such as HPV testing and HPV vaccination makes it possible to conceive integrated strategies for the elimination of cervical cancer that have no precedent in the cancer field. HPV tests and HPV vaccines remain, however, too expensive, and large-scale financing of screening and vaccination in less developed countries is sorely lacking., (Copyright © 2011 UICC.)

Excellent recommendations exist for studying therapeutic and diagnostic questions. We observe that good guidelines on assessment of evidence for screening questions are currently lacking. Guidelines for diagnostic research (STARD), involving systematic application of the reference test (gold standard) to all subjects of large study populations, are not pertinent in situations of screening for disease that is currently not yet present. A five-step framework is proposed for assessing the potential use of a biomarker as a screening tool for cervical cancer: i) correlation studies establishing a trend between the rate of biomarker expression and severity of neoplasia; ii) diagnostic studies in a clinical setting where all women are submitted to verification by the reference standard; iii) biobank-based studies with assessment in archived cytology samples of the biomarker in cervical cancer cases and controls; iv) prospective cohort studies with baseline assessment of the biomarker and monitoring of disease; v) randomised intervention trials aiming to observe reduced incidence of cancer (or its surrogate, severe dysplasia) in the experimental arm at subsequent screening rounds. The 5-phases framework should guide researchers and test developers in planning assessment of new biomarkers and protect clinicians and stakeholders against premature claims for insufficiently evaluated products.

Given the strong etiologic link between high-risk HPV infection and cervical cancer high-risk HPV testing is now being considered as an alternative for cytology-based cervical cancer screening. Many test systems have been developed that can detect the broad spectrum of hrHPV types in one assay. However, for screening purposes the detection of high-risk HPV is not inherently useful unless it is informative for the presence of high-grade cervical intraepithelial neoplasia (CIN 2/3) or cancer. Candidate high-risk HPV tests to be used for screening should reach an optimal balance between clinical sensitivity and specificity for detection of high-grade CIN and cervical cancer to minimize redundant or excessive follow-up procedures for high-risk HPV positive women without cervical lesions. Data from various large screening studies have shown that high-risk HPV testing by hybrid capture 2 and GP5+/6+-PCR yields considerably better results in the detection of CIN 2/3 than cytology. The data from these studies can be used to guide the translation of high-risk HPV testing into clinical practice by setting standards of test performance and characteristics. On the basis of these data we have developed guidelines for high-risk HPV test requirements for primary cervical screening and validation guidelines for candidate HPV assays., (Copyright (c) 2008 Wiley-Liss, Inc.)

The decision to introduce liquid-based cytology (LBC) and HPV as screening tests involves criteria based on resource consumption. We used cross-sectional data at recruitment from the NTCC trial [ISRCTN81678807] on 28,000 women aged 35-60, randomised to receive a conventional Pap test or LBC plus HPV. We computed the resources employed to detect a CIN2+ with different screening strategies. In order to result in the same overall cost per CIN2+ detected as screening by conventional cytology, the unit cost of LBC used alone should be less than that of a conventional Pap while its unit cost may be up to 20% higher if HPV-triage for Atypical Squamous Cells of Undetermined Significance is applied together. With the same criterion the unit cost of HPV used alone may be about 20% higher than that of a Pap-test using a 1 pg/ml cut-off and over 40% higher using a 10 pg/ml cut-off. If HPV testing is applied with cytology-triage, a single HPV test may cost 20-30% more than a conventional Pap to result in the same overall cost per CIN2+ detected., ((c) 2007 Wiley-Liss, Inc.)

An inverse relationship between age and human papillomavirus (HPV) prevalence has been reported in many developed countries, but information on this relationship is scarce in many other parts of the world. We carried out a cross-sectional study of sexually active women from the general population of 15 areas in 4 continents. Similar standardised protocols for women's enrolment, cervical specimen collection and PCR-based assays for HPV testing were used. HPV prevalence in different age groups was compared by study area. 18,498 women aged 15-74 years were included. Age-standardised HPV prevalence varied more than 10-fold between populations, as did the shape of age-specific curves. HPV prevalence peaked below age 25 or 35, and declined with age in Italy, the Netherlands, Spain, Argentina, Korea and in Lampang, Thailand and Ho Chi Minh, Vietnam. This was not the case in Songkla, Thailand nor Hanoi, Vietnam, where HPV prevalence was low in all age groups. In Chile, Colombia and Mexico, a second peak of HPV prevalence was detected among older women. In the poorest study areas in Asia (Shanxi, China and Dindigul, India), and in Nigeria, HPV prevalence was high across all age groups. The substantial differences observed in age-specific curves of HPV prevalence between populations may have a variety of explanations. These differences, however, underline that great caution should be used in inferring the natural history of HPV from age-specific prevalences.

Cervical cancer remains a significant public health concern, both at a global and a European level. A number of new technologies such as diagnostic tests for human papillomavirus (HPV) have a potential to assist with the reduction of this disease. However, both the efficacy and the cost-effectiveness of these new technologies must be established in properly designed trials before they can be implemented within national public health programs. Our study reviews the randomized controlled trials that are currently being conducted in Europe to establish the performance of HPV testing as a primary cervical cancer screening test.

A series of 722 lung carcinomas, surgically resected and typed some years ago according to the 1967 WHO classification, was independently reviewed by 2 observers in order to test the reproducibility of histopathological typing when using the criteria of the 1981 WHO classification. Typing was fully agreed upon in 87% of cases. Agreement was very high for squamous-cell, small-cell and adeno-carcinomas (kappa = 0.87, 0.89 and 0.85, respectively) while adenosquamous (kappa = 0.56) and large-cell (kappa = 0.71) carcinomas were more controversial categories. A consensus diagnosis was formulated for lesions with discrepant diagnoses. When comparing the final typing to the previous typing based on the 1967 WHO classification, squamous- and large-cell carcinomas were reduced respectively by 22% and 33% and adenocarcinomas increased by 94% of the original number. The 1981 "adenosquamous carcinoma" category included 2.8% of the tumours, while the corresponding 1967 category "combined epidermoid and adenocarcinoma" was empty. These changes must be taken into account when considering epidemiological studies, especially those aiming at evaluation of the secular trends of lung cancer by cell type.

The use of n-butyric acid has been associated with induction of cell differentiation and bypassing of genetic defects in the suppression of malignancy. This biological response modifier satisfies the requirements for specificity and low toxicity, and its use can be considered as an alternative approach to conventional cancer chemotherapy. However, a lack of clinical efficacy has been observed with butyrate and attributed mainly to the rapid metabolism of the compound. Butyric acid pro-drugs derived from monosaccharides such as 3-O-butanoyl-1,2-O-isopropylidene-alpha-D-glucofuranose (MAG = 3but) have consequently been devised. Pharmacokinetic and biological advantages of MAG = 3but have been previously described. In the present report, we have studied the effect of MAG = 3but on murine interferon-alpha, beta (IFN) anticellular, antitumor and antiviral activities. In vitro, it appears that MAG = 3but predisposes malignant MSV cells to a later, complete establishment of the antiproliferative and the cell-differentiating effects of IFN, and the antiviral action of the latter in the same line of cells infected with encephalomyocarditis (EMC) virus. In vivo, combined treatment with MAG = 3but and IFN protects mice effectively against the fatal development of ascitic sarcoma 180 TG and the lethal effect of EMC virus infection.

The interest of butyric salts is based on their capacity to promote differentiation of malignant cells and inhibition of tumor development. The phenotypic modifications are rapidly reversible and require the continuous presence of butyric salts in the target area, which raises problems for therapeutic applications. We show here that the covalent binding of n-butyric acid on natural polyhydroxylated compounds such as monosaccharides, especially 3- or 6-O-butanoyl-1,2-O-isopropylidene-alpha-D-glucofuranose, retains the majority of the biological properties of n-butyric acid. The delayed degradation of these covalent compounds is associated with an improved maintenance of cell differentiation and anti-tumor protection in mice. These butyric complexes thus seem potentially useful for therapeutic applications.

A population-based case-control study on lung cancer was conducted in 2 industrialized areas of northern Italy. Cases (126) were all males who died from lung cancer between 1976 and 1980. Controls (384) were a random sample of males dying from other causes during the same period. Jobs held during working life have been analyzed according to a list of occupations already known to be causally associated with lung cancer (list A) and a list of occupations suspected of being so (list B). Attributable risk percentages in the population for occupations included in either list A or B were about 36% and 12% in the 2 areas. Welders or workers in industries in which welding is common showed elevated odds ratios: 2.9 for welders (95% CI 0.9-9.8); 4.9 (1.1-22.9) for structural metal workers; 11.4 (2.6-49.9) for workers in structural metal production. Other job categories associated with lung cancer included: electricians and workers in electrical machine production, woodworkers (in furniture or cabinet making, but not in carpentry or joinery) and cleaning services. Smoking did not seem to exert a substantial confounding effect. Attributable risk percentages for tobacco smoking were about 78% and 76% in the population of the 2 areas.