Prospective study on the relationship between cervical neoplasia and herpes simplex type-2 virus. I. Epidemiological characteristics

Genital Herpes: Gender Comparisons and the Disease Experience

The purpose of this descriptive study was to examine gender differences in the disease experience of persons who have genital herpes. Participants were 60 volunteers (34 females, 26 males) with recurrent genital herpes. Their average age was 31.7 years and the average length of time since diagnosis was 5.3 years. They completed questionnaires that included items about disease characteristics, disease stressors, and disease impact. The majority of reported stressors related to the consequences of the disease. A wide diversity of stressors were described, and results gave evidence of gender similarities in the disease experience. Exceptions were that women reported experiencing more worry with regard to negative effects on future and present health, disruption of daily activity, and disease symptoms. Men reported that recurrences last longer. Both disease symptoms and the presence of an intimate relationship were related to the perceived disease impact. Implications for sensitive interventions are discussed.

Herpes simplex virus type 2 and the risk of cervical cancer: a meta-analysis of observational studies

OBJECTIVES

To assess whether herpes simplex virus type 2 (HSV-2) infection has an effect on the risk of cervical cancer.

METHODS

A systematic literature search of PubMed, Embase, Web of Science, and Scopus from their inception through July 2013 was conducted and reference lists of retrieved articles were reviewed. Information on the characteristics of the included studies, risk estimates, and control for possible confounding factors was extracted independently by two investigators. A random effects model was used to calculate the pooled risk estimates.

MAIN RESULTS

Sixteen articles with 20 studies (14 case control and 6 longitudinal) involving 3,337 patients with cervical cancer were included. Compared with individuals who did not experience HSV-2 infection, the pooled ORs of cervical cancer for individuals with HSV-2 infection were 1.37 (95 % CI 1.12-1.69) for traditional case-control studies and 1.04 (95 % CI 0.82-1.31) for prospective or retrospective nested case-control studies.

CONCLUSIONS

Given that a longitudinal study gives a higher level of evidence than a traditional case-control study, the existing observational epidemiological evidence do not support a harmful effect of HSV-2 infection on cervical cancer.

Current perspectives on HPV vaccination: a focus on targeting the L2 protein

ABSTRACT: 

Thirty years ago, human papillomavirus types 16 and 18 were isolated from cervical carcinomas, and it has been almost 10 years since the introduction of the first prophylactic virus-like particle (VLP) vaccine. The VLP vaccines have already impacted the reduction of pre-malignant lesions and genital warts, and it is expected that vaccination efforts will successfully lower the incidence of cervical cancer before the end of the decade. Here we summarize the historical developments leading to the prophylactic HPV vaccines and discuss current advances of next-generation vaccines that aim to overcome certain limitations of the VLP vaccines, including their intrinsic narrow range of protection, stability and production/distribution costs.

[Nobel price for vaccination against cervical cancer: current data and guidelines]

Harald zur Hausen received the Nobel price for Medicine in 2008 for his seminal research on human papilloma viruses and their association with anogenital diseases. On the basis of his work highly effective prophylactic vaccines have been developed. Clinical studies have shown nearly 100% seroconversion and an excellent safety profile as well as greater than 96% efficacy against HPV infection and premalignant dysplasia, induced by HPV types covered by the vaccine. Due to the convincing data of phase II and III clinical trials the introduction of HPV vaccination was recommended by health authorities and scientific committees in Germany. The development and availability of guidelines and evidence-based recommendations should support the introduction of the vaccine and widespread vaccination.

Papillomaviruses in the causation of human cancers - a brief historical account

Approximately 35 years ago a role of human papillomaviruses (HPV) in cervical cancer has been postulated. Today it is well established that this very heterogeneous virus family harbours important human carcinogens, causing not only the vast majority of cervical, but also a substantial proportion of other anogenital and head and neck cancers. In addition, specific types have been linked to certain cutaneous cancers. In females, HPV infections on a global scale account for more than 50% of infection-linked cancers, in males for barely 5%. Vaccines against the high risk HPV types 16 and 18 represent the first preventive vaccines directly developed to protect against a major human cancer (cervical carcinoma). This review will cover some of the historical aspects of papillomavirus research; it tries briefly to analyze the present state of linking HPV to human cancers and will discuss some emerging developments.

Evidence for benefits from treating cervical ectopy: literature review

CONTEXT AND PURPOSE

Uterine cervical ectopy (cervical erosion) is today considered to be a physiological condition, but there still seems to be a strong tendency towards treating it. The purpose of this study was to review the medical literature for evidence regarding benefits from treating cervical ectopy.

METHODS

The following databases were reviewed: Medical Literature Analysis and Retrieval System Online (Medline), Excerpta Medica Database (Embase), Literatura Latino-Americana e do Caribe em Ciências da Saúde (Lilacs) and Cochrane Library databases. In addition, six medical textbooks were consulted.

RESULTS

The review showed that: 1) there is probably an association between ectopy and higher risk of Chlamydia trachomatis, human papillomavirus and human immunodeficiency virus infection; 4) there is probably an association between ectopy and cervical intraepithelial neoplasia; 5) there is an association between ectopy and mucous discharge and nocturia; and 6) there is no evidence of an association between ectopy and cervical cancer, or of protection against cervical cancer associated with ectopy treatment.

CONCLUSIONS

1) No data were found in the medical literature to support routine treatment for ectopy; 2) Treatment could be recommended for symptom relief, but more symptoms are attributed to ectopy than could be demonstrated in a controlled study; 3) Further studies to test the hypothesis of protection against cervical cancer associated with treatment are necessary.

Vaccines against human papillomaviruses--a major breakthrough in cancer prevention

Carcinoma of the cervix (CaCer) is the second most frequent malignancy in women on a global scale. Epidemiological studies carried out at the beginning of the second half of the 20th century showed that CaCer was of infectious nature and that its agent was transmitted by sexual intercourse. For some 15 years, herpes simplex virus type 2 (HSV2), the genital herpes virus, was suspected to be the etiological agent. This hypothesis was disproved just in the time when the first convincing evidence that the agents of the disease were human papillomaviruses (HPVs) was produced. Copious new findings obtained during the 1980's and 1990's unequivocally confirmed that HPVs were the causative agents. The most dangerous among the over 100 HPV types are types 16 and 18, which together account for over 70% of CaCer cases and very likely also for most of the other malignancies of the anogenital region and the oropharynx. Extensive research of the HPV biology and immunology enabled the development of vaccines based on the s.c. virus-like particles (VLP) prepared by genetic engineering. At present, there is one HPV vaccine on the market; it contains, besides types 16 and 18, also types 6 and 11, the causative agents of certain benign tumours of the genital area and of the larynx. A new vaccine, comprising types 16 and 18 only, the product of another firm, is to appear on the market soon. Both vaccines have already been tested in extensive clinical trials. They are nearly 100% effective, only very weakly reactogenic and they undoubtedly belong among the most perfect vaccines ever produced. The darker side of the anti-HPV vaccines is their high price, the fact that the highest benefits they bring will only become evident in 20 or 30 years, and that they do not afford protection against all oncogenic HPVs. It is therefore imperative that organized cytological screening be continued: it is destined to remain the main instrument of CaCer prevention for several decades. With all probability also other types of vaccine are under development, viz. VLP-based vaccines, whose range of applicability will be wider than that of the present preventive vaccines, as well as vaccines that will, hopefully, be able to inhibit already progressing infection or will be utilizable in CaCer immunotherapy.

Prophylaktische und therapeutische HPV-Impfstoffe

Papilloma viruses (PV) have been known to cause benign and malignant tumors in animals for more than 100 years. It took over 20 years to win general acceptance for their causative role in anogenital carcinomas in humans in particular in cervial carcinoma. Extensive research has led to the development of a prophylactic vaccine which is now commercially available. It remains to be investigated if HPV-specific therapeutic vaccines can be developed.

Cervical HPV infection and neoplasia in a large population-based prospective study: the Manchester cohort

Cytology and histology records and cervical samples for HPV assay were obtained from a prospective cohort of 49 655 women attending clinics for routine cervical cytology in or near Manchester between 1988 and 1993. The women were followed up for cytological abnormality and neoplasia through the cytology laboratory's records. HPV at entry was assayed in an age- and period-stratified random sample of 7278 women and in prevalent and incident CIN3 cases. The prevalence of newly diagnosed CIN3 increased with time since last normal smear, indicating that most cases persist for several years. CIN3 prevalence did not increase further for screening intervals exceeding 5 years, however, suggesting that CIN3 eventually regresses cytologically. CIN2 prevalence increased less steeply with screening interval, while the prevalence of lesser abnormality was almost independent of screening interval. The prevalence of oncogenic HPV at entry declined from 19% among women aged under 25 to less than 3% at age 40 or above. Oncogenic HPV infection was strongly predictive of subsequent CIN3 (OR 17.2, 95% CI 10.4–28.4), but only weakly related to CIN2 (OR 2.3, 95% CI 0.5–10.7) and lesser abnormality (OR 1.4, 95% CI 0.8–2.5). At current incidence rates, the lifetime risk of developing CIN3 will be 9% in this population. The cumulative risk of CIN3 diagnosis among cytologically normal women with oncogenic HPV detected at entry was 28% (CI 18–43%) after 14 years. Persistence of oncogenic HPV may be more sensitive and specific than cytology for early detection of CIN3 and invasive cancer.

Suppression of human papillomavirus gene expression in vitro and in vivo by herpes simplex virus type 2 infection

Recent epidemiological studies have found that women infected with both herpes simplex virus type 2 (HSV-2) and human papillomavirus (HPV) type 16 or HPV-18 are at greater risk of developing cervical carcinoma compared to women infected with only one virus. However, it remains unclear if HSV-2 is a cofactor for cervical cancer or if HPV and HSV-2 interact in any way. We have studied the effect of HSV-2 infection on HPV-11 gene expression in an in vitro double-infection assay. HPV transcripts were down-regulated in response to HSV-2 infection. Two HSV-2 vhs mutants failed to reduce HPV-16 E1;E4 transcripts. We also studied the effect of HSV-2 infection on preexisting experimental papillomas in a vaginal epithelial xenograft model. Doubly infected grafts demonstrated papillomatous transformation and the classical cytopathic effect from HSV-2 infection. HPV and HSV DNA signals were mutually exclusive. These studies may have therapeutic applications for HPV infections and related neoplasms.

Prospective study on cervical neoplasia: presence of HPV DNA in cytological smears precedes the development of cervical neoplastic lesions

OBJECTIVES

The principal aim of the study was to verify whether HPV infection in healthy women, as determined by HPV DNA detection, was associated with an increased risk of development of cervical lesions.

METHODS

Cervical smears collected at enrolment into the prospective study conducted in Prague during 1975-83 were tested for the presence of HPV DNA by means of a polymerase chain reaction (PCR) using the general GP5/6 primers and a mixture of primers specific for the E6 gene. 120 smears from patients in whom cervical neoplasia had been detected in the course of the prospective study and 208 smears from control women who had remained healthy throughout the observation period were analysed. Patients and controls were matched by age, number of sexual partners, age at first intercourse, and smoking habit. Patients were divided into three groups, A, B, and C, according to their cytological, colposcopic, and histological findings at enrolment. Group A consisted of 67 women found ill at enrolment, group B of 26 women with slightly suspicious findings, while group C comprised 27 women with normal findings at enrolment. In addition, sera taken at enrolment from these patients and controls were tested for the presence of antibodies reactive with virus-like particles (VLPs) of HPV 16, 18, and 33.

RESULTS

For the whole cohort, there was a statistically highly significant difference in the presence of HPV DNA between patients and controls. Furthermore, the difference in the presence of HPV DNA between patients and controls was highly significant not only in those who had been found ill at enrolment (group A) but, most importantly, also in women who had developed the disease in the course of the follow up (groups B and C). Women positive for HPV DNA possessed HPV antibodies to VLP16, 18 and 33 significantly more often than those who were free of HPV DNA.

CONCLUSION

This indicated that healthy women who were positive for HPV DNA at enrolment were at an increased risk of developing cervical neoplasia (OR = 18.5; CI 5.9 to 57.6).

Update on cancer control in women

The global cancer burden in women appears to have stabilized according to the most recent estimates available although the distribution of cancer types appears to be changing with a sharp contrast between the increase in the absolute numbers of breast cancers and a decline in cervix cancers. Prospects for cancer control in women appear to be good within our current knowledge and deserve close attention. Rates of lung cancer in women are increasing substantially in many countries and seem set to overtake breast cancer as the commonest form of cancer death in women in many parts of the world. These changes are due to the effects of cigarette smoking, a habit which women widely embraced during the second half of the last century. The high levels of smoking currently in young women, which have yet to have their full impact on death rates, constitute an important hazard not only for future cancer risks but for several other important causes of death. There is strong and consistent evidence that increased consumption levels of fruit and vegetables is associated with reduced risks of many common forms of cancer including breast cancer. Although the breast is the commonest form of cancer in women in most western countries, the etiology of this disease remains elusive and preventable causes remain to be identified. Endogenous hormones also appear to have a role in cancer risk in women: oral contraceptives seem to increase slightly the risk of breast cancer in users in the use and in the immediate post-use period, but 10 years after cessation the risk again returns to that of never users. Oral contraceptive usage also appears to be protective against ovarian and endometrial cancer. The use of hormonal replacement therapy (HRT) appears to increase the risk of endometrial cancer and a positive association with breast cancer risk appears to exist. Within our current knowledge of the epidemiology of cancer in women, the most important preventive strategies would appear to be the prevention of cigarette smoking and increased dietary intake of vegetables and fruits. Screening has also shown to be effective in reducing incidence and mortality of cervix cancer and mortality from breast cancer. Although more work is needed, it is becoming clear that there could be an important role of HPV testing to further enhance cervix cancer screening. There are important variations in survival from a variety of cancers which are due to factors unrelated to the tumor behavior and that there are significant variations in survival from cancer. Reduction of these gaps could lead to a reduction in cancer mortality and contribute towards increased prospects for cancer control in women.

Risk factors for pre-cancerous lesions of the cervix

Studies on risk factors for pre-cancerous lesions of the uterine cervix have shown strong association with sexual practice. Women with multiple sexual partners and intercourse at early age are at high risk. A role of male partners in further enhancing the risk has been identified. All these support the hypothesis relating to a sexually transmissible aetiological agent. An extensive review of the literature on the risk factors for pre-cancerous lesions of cervix has been carried out. The risk factors were grouped into genital, sexual, chemical, dietary and life factors. Human papilloma virus (HPV) is the major infectious aetiological agent associated with the development of pre-cancerous lesions of cervix. Other co-factors such as multiple sexual partners of the male as well as the female and early age of first intercourse are also involved at the critical aetiological step of progression from low-grade to high-grade lesions. The role of other infectious agents in terms of supportive or interactive effects is not clear. No independent effect for herpes simplex virus 2 on risk is observed. Other risk factors include cigarette smoking, oral contraceptive usage, certain nutritional deficiencies and poor personal hygiene. However, it is not clear whether these factors operate independently from HPV. There is no consistency in the independent effect of these factors on the development of low- to high-grade lesions of cervix. There is a similarity in the patterns of risk between pre-cancerous lesions of the cervix and cervical cancer. Monogamy, late commencement of sexual activity, personal hygiene and use of barrier contraceptive methods help towards primary prevention. In the long-term, primary prevention of cervical neoplasia through HPV immunization of population may be a possibility.

Papillomavirus detection: demographic and behavioral characteristics influencing the identification of cervical disease

OBJECTIVE

This study was undertaken to assess the association between detection of high-risk types of human papillomavirus and various demographic and behavioral characteristics and to further relate this association to cervical histopathologic findings.

STUDY DESIGN

A total of 1007 patients with a Papanicolaou test result reported as high-grade squamous intraepithelial lesion or with 2 results reported as atypical squamous cells of undetermined significance or low-grade squamous intraepithelial lesion were referred from city and county clinics to a colposcopic clinic. All women had a cervical smear obtained, underwent colposcopically directed biopsy and endocervical curettage, and had a specimen taken for human papillomavirus deoxyribonucleic acid detection by polymerase chain reaction. Demographic information was obtained from each patient.

RESULTS

Human papillomavirus deoxyribonucleic acid was identified in 655 (66%) of the specimens. High-risk human papillomavirus types (16, 18, 31, 33, and 35) were detected in 463 (70.7%) of these specimens. The prevalence of evidence of human papillomavirus (koilocytosis) and grade 1 cervical intraepithelial neoplasia in the biopsy specimen decreased significantly with age, whereas the prevalence of grade 2 or 3 cervical intraepithelial neoplasia in the biopsy specimen increased with age. There was a significant age-dependent decreasing trend in detection of high-risk human papillomavirus deoxyribonucleic acid among women who had human papillomavirus-associated changes, grade 1 cervical intraepithelial neoplasia, and grade 2 or 3 cervical intraepithelial neoplasia in the biopsy specimen. The prevalences of high-risk human papillomavirus among patients with grade 1 cervical intraepithelial neoplasia and grade 2 or 3 cervical intraepithelial neoplasia were similar, and both were significantly higher than among women with no evidence of cervical intraepithelial neoplasia or koilocytosis in the biopsy specimen. Risk factors associated with grade 2 or 3 cervical intraepithelial neoplasia were different from those associated with human papillomavirus-associated changes and with grade 1 cervical intraepithelial neoplasia.

CONCLUSION

The detection of high-risk human papillomavirus was age-dependent for all histologic categories. Patients with grade 2 or 3 cervical intraepithelial neoplasia had a prevalence of high-risk human papillomavirus that was similar to that among women with grade 1 cervical intraepithelial neoplasia but significantly higher than that among women whose biopsy specimens appeared normal or demonstrated only the presence of human papillomavirus-induced changes (koilocytosis). This suggests that separation of human papillomavirus-associated changes only from grade 1 cervical intraepithelial neoplasia may be of significance in tissue diagnosis.

Prospective study on cervical neoplasia IV. Presence of HPV antibodies

Sera collected in the course of a prospective study carried out in Prague in 1975-1983 were assayed for the presence of human papillomavirus (HPV) antibodies. Women with cervical neoplasia proven by biopsy at enrollment possessed antibodies to peptides derived from E2, E4 and E7 proteins of HPV16 and to virus-like particles (VLPs) of HPV16, -18 and -33 significantly more frequently than matched controls. Women without cervical neoplasia at enrollment who developed the disease in the course of the study differed from matched controls by a higher prevalence of antibodies against VLPs of HPV16 and -18 but not against early antigens of HPV16. In 19 of the latter subjects, paired serum specimens were tested, the first samples having been taken at enrollment and the second at diagnosis. Development of the disease was associated with seroconversion from negativity to positivity to at least one HPV antigen in 11 (57.9%) women.

Cancer, cigarette smoking and premature death in Europe: a review including the Recommendations of European Cancer Experts Consensus Meeting, Helsinki, October 1996

Cigarette smoking has been clearly and unambiguously identified as a direct cause of cancers of the oral cavity, oesophagus, stomach, pancreas, larynx, lung, bladder, kidney and leukaemia, especially acute myeloid leukaemia. Additionally, cigarette smoking is a direct cause of ischaemic heart disease (the commonest cause of death in western countries), respiratory heart disease, aortic aneurysm, chronic obstructive lung disease, stroke, pneumonia and cirrhosis and cancer of the liver. Cigarette smoking can kill in 24 different ways and, although smoking protects against several fatal and non-fatal conditions, the adverse effect of smoking on health is largely negative. In developed countries as a whole, tobacco is responsible for 24% of all male deaths and 7% of all female deaths: these figures rise to over 40% in men in some countries of central and eastern Europe and to 17% in women in the United States. The average loss of life of smokers is 8 years. Among United Kingdom doctors followed for 40 years, overall death rates in middle age were about three times higher among doctors who smoked cigarettes as among doctors who had never smoked regularly. About half of all regular cigarette smokers will eventually be killed by their habit. The important information is that it is never too late to stop smoking: among United Kingdom doctors who stopped smoking, even in middle age, there was a substantial improvement in life expectancy. World-wide, smoking is killing three million people each year and this figure is increasing. In most countries the worst is yet to come, since by the time the young smokers of today reach middle or old age there will be about 10 million deaths/year from tobacco. Approximately 500 million individuals alive today can expect to be killed by tobacco, 250 million of these deaths will occur in middle age. Tobacco is already the biggest cause of adult death in developed countries. Over the next few decades tobacco could well become the biggest cause of adult death in the world. For men in developed countries, the full effects of smoking can already be seen. Tobacco now causes one-third of all male deaths in middle age (plus one fifth in old age). Tobacco is a cause of about half of all male cancer deaths in middle age (plus one-third in old age). Of those who start smoking in their teenage years and keep on smoking, about half will be killed by tobacco. Half of these deaths will be in middle age (35-69) and each will lose an average of 20-25 years of non-smoker life expectancy. In non-smokers in many countries, cancer mortality is decreasing slowly and total mortality rapidly. The war against cancer is being won slowly: the effects of cigarette smoking are holding back this victory. Lung cancer now kills more women in the United States each year than breast cancer. For women in developed countries, the peak of the tobacco epidemic has not yet arrived. Tobacco now causes almost one-third of all deaths in women in middle age in the United States. Although it has only 5% of the world's female population, the United States has 50% of the world's deaths from smoking in women. Tobacco smoking is a major cause of premature death. Throughout Europe, in 1990 tobacco smoking caused three quarters of a million deaths in middle age (between 35 and 69). In the Member States of the European Union in 1990 there were over one quarter of a million deaths in middle age directly caused by tobacco smoking: there were 219700 in men and 31900 in women. There were many more deaths caused by tobacco at older ages. In countries of central and eastern Europe, including the former USSR, there were 441200 deaths in middle age in men and 42100 deaths in women. There is a need for urgent action to help contain this important and unnecessary loss of life. In formulating Recommendations, the European Cancer Experts Consensus Committee recognised that Tobacco Control depends on various parts of society and not only on the individual.

Epidemiology of cervical intraepithelial neoplasia: the role of human papillomavirus

The evidence implicating specific HPV types in the aetiology of cervical cancer is now strong enough to establish a causative role. HPV infection of the cervix affects the developing immature metaplastic cells of the transformation zone. Cervical neoplasia can be viewed as the interaction of high risk papillomavirus and immature metaplastic epithelium. Once maturity is reached, there is minimal risk of subsequent development of cervical squamous neoplasia. Exposure to HPV is an extremely common event, especially in young sexually active women. Yet, despite frequent HPV exposure at that phase of life in which the cervical transformation zone is at its most vulnerable, established expressed disease is relatively uncommon. Most studies in which the natural history of CIN is not altered by cervical biopsy reveal a progression rate from low to high grade CIN of less than one third. Where viral type is taken into account, however, the progression rate from normal but high risk HPV-infected cervical epithelium to CIN 2 or 3 is higher. Despite this, most cervical abnormalities will not transform into invasive cancer, even if left untreated. The variance between the high rate of HPV infection, the intermediate rate of CIN and the relatively low rate of cervical cancer establishes a stepwise gradient of disease of increasing severity with decreasing prevalence. In an immunocompetent host, HPV infection alone does not appear to be sufficient to induce the step from high grade CIN to invasion. Epidemiological studies indicating that HPV infection with oncogenic viral types is far more common than cervical neoplasia suggest the necessity of cofactors in cervical carcinogenesis. The long time-lag between initial infection and eventual malignant conversion suggests that random events may be necessary for such conversion, and the spontaneous regression of many primary lesions suggests that most patients are not exposed to these random events. Potential cofactors include cigarette smoking, hormonal effects of oral contraceptives and pregnancy, dietary deficiencies, immunosuppression and chronic inflammation. In those women who develop cervical cancer, malignant progression is rarely rapid, more commonly taking many years or decades. Malignant progression has been documented in patients who presented initially with only low grade HPV-induced atypia. On the other hand, progression may be a misnomer, as 'apparent' progression may really represent adjacent 'de novo' development of higher grade CIN. Although most cervical cancers contain high risk HPV types, up to 15% of such cancers test negative for HPV, raising the possibility that a few, usually more aggressive, cervical cancers may arise from from a non-viral source.(ABSTRACT TRUNCATED AT 400 WORDS)

Lack of detection of human papillomavirus (HPV) in transformed laryngeal keratoses by in situ hybridization (ISH) technique

Laryngeal keratosis (LK) is a precancerous mucosal change with a variable possibility of malignant transformation. Recent studies evidencing HPV-DNA genomes in a large series of non-malignant and malignant laryngeal lesions suggest a role of HPV in the transformation of laryngeal lesions possibly in synergistic interaction with other carcinogens. In this study, we analyzed 115 biopsy specimens from benign laryngeal lesions to evaluate the risk of malignant transformation and its relationship to degree of dysplasia and to histological features of virus cell infection. The rate of transformation of LK was 8% (9/115). Our results indicate that the risk of transformation in laryngeal keratoses without dysplasia (LKWOD) is lower than that in laryngeal keratoses with dysplasia (2.2% vs 25%, respectively) (p < 0.05). An increased risk of malignant evolution in laryngeal keratoses with dysplasia (LKWD) was also related to the degree of dysplasia (rate of transformation of 12.5, 22.2 and 36% in mild, moderate and severe dysplasia, respectively). Histological features suggesting HPV infection (koilocytic-like atypia and epithelial papillary hyperplasia) were found in 6 LK only, no case subsequently developing cancer. In both benign and transformed LK, analyzed by ISH, we failed to detect HPV genomes, suggesting a major role of others carcinogens, such as tobacco and/or alcohol, in the transformation of LK.

Infection and cancer: current state of art

Empirical evidence of the association of cancer with parasitic and viral infectious agents has been recognized earlier. Today, viruses are thought to account for about 10% of all cancers and they take a central place in experimental cancer research. This area has expanded tremendously with modern molecular biology techniques, the knowledge of gene expression, cellular enzyme and mechanisms of transformation. However, the last proof of causality is not yet available. Serologic, virologic, experimental and protective evidence is needed to confirm the assumptions in this rapidly developing field of research. The prevention of hepato-cellular carcinoma by effective vaccines now available is, in the opinion of the WHO, at least theoretically possible.

Use of the polymerase chain reaction to study the relationship between human papillomavirus infections and cervical cancer

Although it is now evident that human papillomaviruses (HPV) are strongly associated with cervical cancer, their etiological role in the oncogenesis of this disease is still unknown. However, HPV screening may identify women at risk of acquiring this disease. With the recent development of the polymerase chain reaction (PCR), it has become possible to detect small numbers of human papillomavirus genomes in clinical samples. The sensitivity and specificity of this technique, together with the possibility of performing the test on crude cervical scrapes, makes PCR the method of choice for screening. In this paper, data on the detection of human papillomavirus by PCR are presented and the applicability of this technique for the screening of human papillomavirus genotypes is evaluated. The question arises whether screening for diagnostic purposes must include all the human papillomavirus types associated with infections of the genital tract or only those which are strongly associated with cervical cancer (HPV 16 and HPV 18). It is proposed that an international council must be created that is responsible for standardised epidemiological screening strategies and follow-up programmes.

A research for the relationship between human papillomavirus and human uterine cervical carcinoma. I. The identification of viral genome and subgenomic sequences in biopsies of Chinese patients

Biopsies from 318 cases with squamous cell carcinoma of the uterine cervix, 48 with cervical and vulvar condylomata, 14 with cervical intraepithelial neoplasia (CIN), 34 with chronic cervicitis and 24 with normal cervical epithelium were collected from different geographic regions with different cervical cancer mortalities. The DNA.DNA dot-blot and Southern blot hybridization results show that there is a close relationship between HPV-16 and the uterine cervical squamous cell carcinoma in China. One very interesting observation is that the finding of HPV-16-homologous DNA differs significantly among five geographic regions, and corresponds with the mortalities from cervical cancer of these five regions. HPV-11 was found mainly in benign lesions. The rate of detection of HPV-16 in Chinese women increased from 8.3% in normal cervical epithelium to 20% in chronic cervicitis, 28% in cervical condyloma, 50% in CIN and 60.4% in cervical cancer. It is suggested that HPV-16 infection may be an etiological factor in the development of human cervical carcinoma. From the results of Southern blot hybridization, it appeared that HPV-16 DNA had been integrated into the genome of the host cell in cervical cancer. Whereas the HPV-16 DNA sequence was only present as an episome in normal cervical epithelium and cervical benign lesions. The rate of occurrence of E6-E7 genes is the highest (88.9%) compared with that of other subgenomic fragments of HPV-16 in specimens of human cervical cancer in China. This implies that E6 and E7 may be the oncogenic genes of HPV-16 and play an important role in the carcinogenesis of human cervical epithelial cells. The amplification and rearrangement of the c-myc protooncogene are closely associated with the occurrence of cervical cancer. The results presented here revealed that the activated c-myc oncogene may cooperate with HPV-16 in the carcinogenic processes.

Endocervical carcinoma

The past two decades have seen an increase in the incidence of endocervical carcinoma. Numerous studies have increased understanding of these tumors; hormonal therapy, human papilloma virus, and other cofactors have been implicated in the etiology of endocervical carcinoma. Early diagnosis is difficult: precursor lesions to adenocarcinoma in situ are still poorly defined and understood, and there may be a rapid transit time from in situ to invasive carcinoma. The definition of microinvasive adenocarcinoma is not uniformly agreed upon, and at this time the recommendation is not to use the term. Histologic typing and grading of adenocarcinoma may be useful in the prediction of prognosis for patients. Therapy is based upon stage of disease, the most beneficial results being obtained from either radical surgery or combination surgery and radiation therapy.

Role of human papillomavirus in the pathogenesis of genital tract warts and cancer

During the last decade a large number of clinical, epidemiological, and experimental studies have elucidated the role of HPV in the pathogenesis of anogenital cancer. Although the clinical and epidemiological studies have been criticized for a variety of technical and design shortcomings, for the most part they have independently reached the same conclusion--there is a strong association between the presence of specific types of HPV and the development of anogenital cancer. Similarly, laboratory studies clearly indicate that specific types of HPV act in concert with other cellular changes to transform a variety of cell types in vitro, including human cervical epithelial cells. Over the next decade the challenge is twofold. First we need to define precisely the mechanisms by which HPV either by itself or in concert with other factors, acts to transform anogenital epithelial cells. These studies will, it is hoped, identify important cofactors in the transformation process and determine the role of host immunity. Second, we need to determine the clinical applicability of the association between HPV and anogenital cancer. Large clinical studies will determine whether HPV testing of asymptomatic patients facilitates the detection of patients at risk for developing cervical cancer and whether the presence of a specific type of HPV in a cervical cancer actually affects a patient's prognosis. As the answers to these and other questions become available, we will be in a better position to assess the clinical importance of the associations between HPV and anogenital cancer.

Search for human papillomavirus, herpes simplex virus and c-myc oncogene in human genital tumors

We tested grade III cervical intra-epithelial neoplasms (CIN III), genital invasive carcinomas and healthy genital tissues for the presence of a number of viral and cellular parameters, considered to be risk factors in genital oncogenesis. The results show that: (I) about 30% of genital tumors had homology to HSV-2 BglII N and/or BamHI E DNA fragments; (2) positivity to HSV-2-specific protein ICP10, encoded by sequences within the HSV-2 BamHI E DNA fragment, was detected in 29/55 neoplastic genital tissues but not in healthy genital tissues or tumors at other sites; (3) HPV-16 DNA was found in about 50% of tumor samples, but none of the positive tissues reacted to HPV capsid protein or to the protein encoded by the HPV-16 E6 ORF; (4) 6/8 tumor samples showing homology to HSV-2 DNA fragments also hybridized to HPV-16 DNA; (5) c-myc amplification was not detected in any of the analyzed samples, but tissues from 4 patients were positive for c-myc expression. None of the considered factors was present in all the analyzed samples; nevertheless, some tissues showed the simultaneous involvement of several parameters, suggesting that a number of risk factors may be involved in different steps of human genital oncogenesis.

Significance of smoking and detection of serum antibodies to cytomegalovirus in cervical dysplasia

Cervical biopsy specimens from 422 women attending a colposcopy clinic showed various grades of dysplasia in 387 and no evidence of dysplasia in 35. Of the women with dysplasia (CIN I, II or III) 67% were smokers and 33% were non-smokers compared with 43% smokers and 57% non-smokers in those without evidence of dysplasia. Of the women with CIN I 56% were smokers and 44% were non-smokers; 66% of those with CIN II were smokers and 34% were non-smokers (P less than 0.02), and 71% of those with CIN III were smokers (P less than 0.01). There were no significant differences between the smokers and non-smokers in the proportion of women who had had either a miscarriage or an abortion, in the prevalence of condylomata acuminata, and the use of oral contraception or barrier methods. Neither were there any significant differences in numbers of patients seropositive for cytomegalovirus or in CMV antibody titres among the groups. The detection of koilocytic cells in cervical biopsies showed a significant difference between smoking and non-smoking groups which reflected a significant increase in koilocytosis in smokers with CIN III.

Simultaneous presence of herpes simplex and human papilloma virus sequences in human genital tumors

Herpes simplex virus (HSV) and human papillomavirus (HPV) sequences were analyzed in tumors of the female lower genital tract, by probing DNA from 13 intraepithelial and 30 invasive neoplastic lesions with radiolabelled HPV-16 and HPV-18 DNA as well as cloned fragments of HSV-2 DNA. Careful removal of stromal tissue from the pathological specimens allowed authentic tumor DNA to be processed. Normal genital tissue obtained from the patients and genital condylomata were included as internal controls. The presence of HPV-16 or 18 DNA was detected in 12/13 (92.3%) intraepithelial neoplasms and in 16/30 (53.3%) invasive carcinomas. No significant difference was detected in titer or frequency of antibodies to HPV group-specific antigen in sera from patients and controls. Hybridization to BgIII N fragment of HSV-2 DNA was detected in 4/13 (30.8%) intraepithelial neoplasms and 4/30 (13.3%) invasive carcinomas but in none of the control tissues. All the 8 samples harboring HSV-2 homologous sequences were also positive for HPV, supporting the hypothesis of a synergistic association between the 2 viruses. The hybridization analyses performed to study c-myc involvement in genital oncogenesis did not reveal c-myc amplification in either invasive or pre-invasive lesions.

Causes and management of cervical intraepithelial neoplasia

The evidence for human papillomavirus (HPV) playing a role in the pathogenesis of lower genital neoplasia is reviewed. It is likely that this group of viruses is etiologically important. It is suggested that cervical lesions be diagnosed as flat condyloma if they contain HPV types six or 11 and as cervical intraepithelial neoplasia (CIN) if they are confined to the epithelium and contain HPV Types 16 or 18 or other types associated with neoplasia. Patients with a Papanicolaou (PAP) smear or clinical evidence of HPV infection in the genital tract should be examined colposcopically, invasive cancer should be excluded, and the HPV-induced lesions should be identified and eradicated.

Sequences homologous to two separate transforming regions of herpes simplex virus DNA are linked in two human genital tumors

Ten human genital invasive squamous cell carcinomas and five human premalignant tissues were analyzed for the presence of selected sets of herpes simplex virus 2 (HSV-2) DNA sequences. Two vulvar tumors and one vulvar dysplastic tissue were found to contain DNA sequences homologous to the BglII O fragment (coordinates 0.38-0.42) and the BglII N fragment (coordinates 0.58-0.63) of HSV-2 DNA. These two fragments overlap the subsets of HSV-1 and HSV-2 DNA sequences (respectively) shown previously to transform cells in culture. Sequences homologous to an additional HSV-2 DNA probe (BglII G) were not detected in the same tumors. Surprisingly, in each of the two positive vulvar tumors, the BglII N and BglII O sequences appeared to be linked, whereas in the standard HSV-2 genome the two fragments are separated by approximately 26 kb. This finding suggested that the two sets of sequences may have rearranged prior to or following the association of the HSV DNA sequences with the tumor cells. The same set of 10 tumors were analyzed for the presence of sequences complementary to human papillomavirus 16 (HPV16) DNA. The HPV16 DNA probe hybridized to three of six cervical tumors, whereas no hybridization was detected with the two vulvar tumors which contained the HSV DNA sequences.

Is your initiator really necessary?

There is little hard evidence for the involvement of specific genotoxic initiators in the pathogenesis of the common carcinoma. Recent findings suggest that sporadic carcinogenesis is a dynamic and probabilistic process which requires a critical mass of abnormal cells for its expression, and that this requirement may distinguish the evolution of carcinomas from that of paediatric or haematologic malignancies. The proposal that specific carcinogens are neither necessary nor sufficient for tumourigenesis is consistent with the growing realization that aberrant expression of specific oncogenes is neither necessary nor sufficient for cellular transformation. These new perspectives have major implications for basic research strategy and public health policy.

Failure to induce cervical cancer in mice by long-term frequent vaginal exposure to live or inactivated herpes simplex viruses

C57 mice aged 8-10 weeks in groups of 50 each received vaginal cotton pellets soaked in lysates of HEp-2 cells, either mock-infected or infected with herpes simplex virus I, herpes simplex virus 2, and highly attenuated recombinant viruses 5 times a week for 89 to 114 weeks. An untreated group was also included. The mock-infected and some of the infected cell lysates were exposed to ultraviolet light at a dose sufficient to inactivate virus. Smears of exfoliated vaginal cells collected once a month and histopathologic sections of genital organs removed at autopsy were coded and examined blind for the presence of abnormal cells indicative of malignant changes and cervical cancer, respectively. Sera collected before termination of the study were tested blind for the presence of antibody to infected cell lysates and to purified herpes simplex virus glycoprotein B. The results were as follows: Over 74% of 826 mice examined at autopsy contained tumors at non-genital sites. The tumors were randomly distributed among the various groups. Gross genital abnormalities were less common in untreated animals than in mice receiving vaginal implants. The fraction of mice which developed cervical cancer diagnosed by histopathologic examination was small (7.2%) and not significantly different among various groups. There was no correlation between the presence of abnormal exfoliated cells indicative of early invasive or invasive cancer lesions and the histopathologically proven diagnosis of micro-invasive or invasive cervical cancer. The incidence and levels of antibody were highest in animals exposed to live virus; some mice exposed to inactivated virus also developed weak or moderately high antibody levels. The presence of antibodies did not correlate with the presence of histopathologically proven cervical cancer. The results do not support the ability of herpes simplex viruses to cause genital neoplasia in mice.

Prospective study on the relationship between cervical neoplasia and herpes simplex type 2 virus. III. Presence of herpes simplex type-2 antibody in sera of subjects who developed cervical neoplasia later in the study

Paired sera taken from 63 subjects who developed cervical neoplasia in the course of a prospective study on this disease were examined for the presence of herpes simplex virus type 2 (HSV-2) antibody. The first serum was taken at enrollment into the study, while the second was obtained after development of the disease, i.e. 2-4 years later. Simultaneously, paired sera from a group of control subjects, who remained free of any cytological and colposcopical abnormalities throughout the study, were also investigated. Controls were matched with patients by age, age at first intercourse, number of sexual partners, smoking habits and history of diathermoelectrocoagulation of ectopic epithelium and transformation zone of the cervix. The first sera from these subjects were obtained at enrollment while the second ones were taken at the end of the study, i.e. 5 to 7 years later. Antibody titres were remarkably stable in both patients and control subjects. Seroconversions from HSV-2 negativity to HSV-2 positivity as measured by the increase in the II/I ratio or development of antibody reactive with HSV-2-specific glycoprotein G were rare and no significant differences between the patients and control subjects were detected. This indicates that the development of the disease was apparently not followed by immediate or early activation of latent HSV-2 infection.

The role of human papillomaviruses in the pathogenesis and histologic classification of precancerous lesions of the cervix

It is clear that the relation between HPV infection and cervical neoplasia is more complex than initially realized. Preliminary molecular virologic data suggest preferential distributions of low- and high-risk HPV types in CIN that tend to correlate with the morphologic appearance. Thus, mild and moderate dysplasias (CIN I and II) contain a diverse distribution of HPV types, including a minority that have a high risk of malignant potential. HPV, therefore, appears to play a major role as a promoter. Neoplastic transformation is probably determined by specific HPV types but, in addition, requires initiation by some other carcinogenic stimulus, e.g., HSV II, cigarette smoking. Despite numerous studies, performed during the past 30 years, the long-term behavior of dysplasia remains uncertain. The natural history of HPV-associated lesions is unknown. Until this information is available, it is recommended that the conventional dysplasia--CIS or CIN nomenclature be used. The presence of associated viral changes can be considered and added to the diagnosis, e.g., "moderate dysplasia (CIN II) with evidence of papillomavirus infection." Treatment should be the same for all intraepithelial lesions, regardless of the presence of morphologic evidence of HPV. In the future, it may be necessary to modify the classification of precancerous lesions of the cervix if it is shown that a specific HPV type induces a characteristic morphologic alteration or that the HPV type, in and of itself, has greater prognostic significance. Until then, confusion will be minimized and management optimized if the conventional dysplasia--CIS or CIN nomenclature is employed.

Comparison of risk factors for cervical cancer in different populations

The incidence of cervical cancer has been found to vary between populations. Risk factors of cervical cancer include early age at first marriage, multiple marriages and antibodies to herpes simplex virus type 2 (HSV-2). The interrelatedness of these risk factors was examined by comparing data collected from 428 cancer cases and 947 control women selected from 6 populations having standardized cervical cancer incidence rates varying from 9.3 to 85.1 per 100,000. Logistic regression analysis revealed that multiple marriages, early age at first marriage or pregnancy and HSV-2 antibodies were all associated with significant risk when all 3 factors were entered into the model. Cervical cancer incidence rates were best predicted by the occurrence of HSV-2 antibodies among control women. To further assess the relation between cervical cancer rates and HSV-2 antibody, 2,306 additional sera representing an 0.8% random sample of females over 9 years of age residing in the Republic of Panama were assayed for antibodies to the virus, and the occurrence of antibodies was correlated with invasive cervical cancer rates specific to each Province. Data from both the random sample and the other study populations yielded a linear relation between the occurrence of HSV-2 antibodies and the incidence of cervical cancer. An exception was found for women living in Herrera Province, Republic of Panama, who had a higher cancer rate than predicted by HSV-2 antibody occurrence. The data suggested that infection with HSV-2 is a co-variable of venereal factors, although a role for the virus in the genesis of a certain proportion of cervical cancers is not excluded.

Association of HPV with human genital tumors

Human papillomaviruses (HPV) are clearly responsible for the induction of genital lesions like condylomata acuminata, bowenoid papules, and flat condylomas. Moreover, the DNA of particular virus types (HPV 16 and 18) is found in a substantial number of invasively growing squamous cell carcinomas of the genital tract, suggesting an etiologic involvement of these viruses in tumor development. Since HPV 16 and 18 as well as other papillomaviruses (HPV 6 or 11) usually present within the benign genital warts can be found in dysplastic lesions of the uterine cervix known as putative precancerous lesions, determination of the virus type might be of diagnostic relevance. Since no type-specific serologic reagents are available, viruses can be identified by nucleic acid hybridization using radioactively labeled HPV DNAs that have been molecularly cloned as probes.

Papillomavirus infection of the lower genital tract: detection of viral DNA in gynecological swabs

A total of 311 smears from the lower genital tract were examined by the filter in situ hybridization method to identify human papillomavirus (HPV) DNA. Of these 311 smears, 229 came from clinically and cytologically negative patients and served as a control group. In this group HPV-DNA was detected in 5 cases (2.2%). Of 82 cytologically positive cases (25 confirmed by histology) 56 (68%) contained HPV-DNA. A high prevalence of HPV 6/11 and absence of HPV 16/18 was found in cases with cytological signs of permissive HPV infection. In mild and moderate dysplasia all viruses occurred at almost the same frequency. In severe dysplasia/carcinoma in situ HPV 16/18 was found 5 times more frequently than HPV 6/11. HPV 16/18 was identified in all 4 invasive cancer cases. Cervical irrigation of colposcopically suspect areas was performed in 15 cytologically and HPV-DNA positive cases using the hydrodynamic filtration method. In 12 cases only the cells obtained from the colposcopically positive areas contained HPV-DNA. The sensitivity and reproducibility of the filter in situ hybridization was shown by: comparing the results obtained by HPV-DNA hybridization using Southern blot analysis of tumor biopsies; analysing the correlation of cytologic diagnosis and presence of HPV-DNA in follow-up examinations, and diagnosing presence or absence of HPV-DNA in parallel filters from the same patients.

A prospective study of association of herpes simplex virus and human papillomavirus infection with cervical neoplasia in women exposed to diethylstilbestrol in utero

One thousand one hundred thirty-four women, enrolled in a prospective study of the development of cervical neoplasia in women exposed to diethylstilbestrol (DES) in utero, were examined at least once a year. Twenty-three women developed cervical intraepithelial neoplasia (CIN) of different degrees during the 7-year follow-up period and were matched with women who did not develop CIN during the study period. Serum samples were obtained at the time of entry into the study and at the time of diagnosis of neoplasia. In the control group, a second serum sample was obtained close to the time when CIN was diagnosed in the other group of women. The sera were studied for antibodies to both types of herpes simplex virus (HSV) by microneutralization assay and by a radioimmunoassay using, as antigens, glycoproteins VP123 for HSV type 1 and VP119 for HSV type 2. Women who developed CIN had, in the enrollment specimen which preceded the neoplasia, a higher rate of antibodies to HSV-1 than did the matched controls (22%), while the two groups did not differ in frequency of antibodies to HSV-2 (9%). Similar differences were observed in the sample drawn at the time of diagnosis of CIN. Women who later developed CIN and had, at the time of entry into the study, cervical epithelial changes associated with DES exposure, were infected with HSV-1 at a higher rate than women who remained free of neoplasia or women with CIN but without DES-associated cervical epithelial changes. Morphologic evidence of associated papillomavirus (HPV) infection was observed in 74% of CIN cases and no such observation was made in biopsy specimens taken prior to development of CIN. Morphologic evidence of HPV infection was found in a women of the control group having squamous metaplasia. HPV structural antigens were found in 3 of 10 CIN I and CIN II cases, and none in the CIN III specimens. The possible role of the HSV and HPV infection in the pathogenesis of cervical neoplasia is discussed.

Prospective study on the relationship between cervical neoplasia and herpes simplex type-2 virus. II. Herpes simplex type-2 antibody presence in sera taken at enrollment

Sera obtained at enrollment in the study from patients suffering from moderate to sever dysplasia (cervical intraepithelial neoplasia grade II), carcinoma in situ (cervical intraepithelial neoplasia grade III) and invasive carcinoma, or developing any of these conditions in the course of the prospective study, and from control subjects, were examined for herpes simplex type-2 (HSV-2) antibody presence. The controls were matched with the patients by age, age at first intercourse, number of sexual partners, smoking habits and history of diathermoelectrocoagulation of the ectopic epithelium and transformation zone of cervix. Only those subjects were selected as controls who remained free of pathological colposcopical and cytological findings throughout the observation period, i.e. for at least 4 years after their serum sample was obtained. The microneutralization test (MNT) and type-2-specific solid-phase radioimmunoassay (SPRIA) were used as serological tests. No difference in the prevalence of HSV-2 antibody between the patients and controls was revealed by either test. Various combinations of the results from the two tests also failed to show any difference between patients and controls. Moreover, no significant differences were observed in the prevalence of HSV-2 antibody between patients suffering from the various pathological conditions and those diagnosed at enrollment and later in the course of the study. These results do not provide any support for the hypothesis of the involvement of HSV-2 in cervical neoplasia.