Smoking as a risk factor in cancer of the cervix: additional evidence from a case-control study

Cigarette smoking, herpes simplex virus type 2 infection, and cervical abnormalities

In a case-control study, we investigated the relation of cigarette smoking and genital herpes virus infection to cervical abnormalities. Although cases and controls differed according to several factors, multiple logistic analyses indicated that age, education, and cigarette smoking were the only independent risk factors for histologically confirmed disease. Relative risk estimates were 1.92 and 3.68 for past and current smokers, respectively. The results indicated that smoking and genital herpes infection did not interact in the risk of cervical abnormality.

Cervical dysplasia: association with sexual behavior, smoking, and oral contraceptive use?

Information on possible risk factors of cervical dysplasia, including indices of sexual behavior, smoking habits, and the use of oral contraceptives was obtained from a case-control study in Ontario in which 250 cases of histologically proved cervical dysplasia and 500 age-matched neighborhood controls were interviewed. Initial analysis showed an increased risk associated with more than one sexual partner, an early age at first intercourse, current smoking, the use and duration of use of oral contraceptives, and education. However, the increased risk of use and duration of use of oral contraceptives and education was reduced after adjustment for indices of sexual behavior and smoking. This finding does not confirm previously reported large adverse effects of pill use. The relationship between smoking and cervical dysplasia might be explained by some agent in cigarette smoke which depresses the immune mechanism, thus permitting a sexually transmitted agent to result in abnormal cellular development that leads to the onset of cervical dysplasia.

Risk factors of squamous cell carcinoma of the skin. A case-control study in the Montreal region

A matched case-control study was undertaken to assess the relative risk associated with known and suspected risk factors of squamous cell carcinoma of the skin among patients in the Montreal region. Three hundred eleven cases histologically diagnosed in 1977 and 1978 in 12 hospitals and meeting strict definition criteria were identified. With the exception of six cases, two controls were matched to each case for sex, age, and hospital of diagnosis. A logistic regression analysis was done. The known host risk factors (eye and hair color, complexion, descent) and nonoccupational sunlight exposure were found to be operative in the Montreal region. After adjusting for these factors, occupational sunlight exposure appeared to be a risk factor. An association was then observed between the risk of squamous cell carcinoma of the skin and tobacco smoking and the use of a sunlamp. Relative risks associated with the above-mentioned factors were estimated.

The impact of screening on the incidence of cervical cancer in England and Wales

Age-specific incidence curves for clinical cancer of the cervix in England and Wales show progressive changes over the period 1963-1978; in particular, a large reduction in incidence is seen in the age group 35-54. Since screening on any scale began in the early 1960s, we have investigated how much of this reduction in incidence in the middle age range can be attributed to detection of pre-invasive disease. Data on registrations of in-situ cancer have been used to estimate the patterns that might have been observed in the absence of screening. The results indicate clear cohort effects on incidence, with rising rates in the generations born 1906-1921 and since 1931, with a fall in the decade between. In addition to this, screening has probably led to a substantial reduction in the number of cases of clinical cancer in women aged 35-54, but has had little effect over the age of 60 where virtually no screening has been performed. Below age 35 the observed increase in incidence may be considerably less than it would have been in the absence of screening.

Antibody to early and late antigens of herpes simplex virus type 1 in patients with oral cancer

HEp-2 cells were infected with herpes simplex virus type 1 (HSV-1) and harvested at selected times thereafter. IgG, IgA, and IgM antibody to virus antigens present in these cells at each time was measured in sera from oral cancer patients, and in matched controls. The IgA response of oral cancer patients was significantly greater than that of controls both at 8 and at 48 hours after infection, but showed no difference in response to HSV-1 virus particles. IgM antibody detected two peaks of antigen synthesis, at 4 and 48 hours after infection. Oral cancer patients had a stronger IgM response than did controls to both early and late peaks; the latter was significant at the 5% level. Oral cancer patients also had a significantly higher IgM response to the virus particle. These results imply the existence of at least two different HSV-1 antigens associated with oral cancer. Both are late antigens; one is recognized by IgA, and the other is recognized by IgM antibody.

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

To determine the risk associated with previous herpes simplex type-2 (HSV-2) infection and possibly other virus infections, a prospective study of cervical neoplasia in more than 10,000 women was performed in the 1975-1983 period. The subjects were selected at random from an alphabetical listing of eligible women living in one district of Prague. At enrollment colposcopy and cervical cytology were performed, a blood sample was taken and data regarding education, socio-economic status, personal habits and sexual and reproduction-associated attributes were obtained from each woman. A total of 10,683 women were enrolled; a complete set of data was obtained in 10,389 women. Women with normal or non-significant findings were invited for further colposcopical and cytological investigations after 2 years and 4 years, the other women were followed at 3- to 6-monthly intervals. In women with highly significant findings, histological investigation was performed. The total of 150 cases of moderate to severe dysplasia (i.e. cervical intraepithelial neoplasia, grade II, CIN II), 83 cases of carcinoma in situ (CIN III) and 21 cases of invasive carcinoma (INCA) were detected. More than 60% of the patients were ill at enrollment, the other cases developed in subjects with originally slightly suspicious (27 CIN II, 17 CIN III, 3 INCA) or negative findings (30 CIN II, 12 CIN III, 3 INCA). Analysis of the data indicated significantly positive correlation of one or more of these clinical conditions with a number of sexual and reproduction-related attributes of which early age at first intercourse was most consistent. Among the other attributes, the smoking habit was associated with the highest risk of developing the disease. A negative correlation of cervical neoplasia with several attributes was demonstrated; of these diathermoelectrocoagulation of the ectopic epithelium and transformation zone of cervix was the most important single protective factor. On the basis of these findings, control subjects were selected for serological studies.

Patterns of anal carcinoma by gender and marital status in Los Angeles County

Marital status and other characteristics of 970 residents of Los Angeles County in whom cancer of the anus (including perianal skin) was diagnosed during the period 1972-1981 were compared with those of all county residents and all other persons in whom cancer was diagnosed during the same period. The incidence rate of anal cancer for single males was 6.1 times that for married males (P less than 0.001). This excess was limited to squamous and transitional cell carcinomas and was reasonably consistent by age, stage, subsite, social class and race. Single women were not at increased risk, but separated and divorced persons of both sexes were at increased risk compared to married persons. Anal cancers were more common in males under the age of 35, after which there was a substantial female predominance. This relative excess in older women occurred at all stages, subsites, and social classes of whites and also in blacks, but not in Hispanics, among whom women had lower overall incidence rates compared to both whites and blacks. The findings were consistent with the hypothesis that sexual activity involving the anus is related to anal cancer. We could not rule out the possibility that anal cancer is related to the acquired immune-deficiency syndrome (AIDS) since the incidence in young single men appears to have increased in 1980 and 1981.

On the nature of the deep cellular disturbances in human-papilloma-virus infection of the squamous cervical epithelium

In the squamous epithelium of the cervix, disturbed deep cells, usually regarded as dysplastic, often underlie superficial koilocytes. Recognition of koilocytosis as a cytopathic effect of human papilloma virus (HPV) prompts reconsideration of the state of the deep cells, which could be non-dysplastic or dysplastic. In the dysplastic states HPV could be non-causative or causative. For dysplastic causation by HPV, a cell-differentiation hypothesis reconciles the coexistence in the epithelium of a permissive HPV infection of the superficial layers (koilocytosis) and a non-permissive cellular infection of the deep layers, which may undergo transformation to dysplasia.

Patterns of cancer in geographic and endogamous subdivisions of the Hutterite Brethren of Canada

The Hutterite Brethren comprise a religious isolate and live on communal agricultural farms (colonies) in North America. In 1976 there were approximately 15,000 Canadian Brethren living in 179 colonies of the three endogamous subdivisions, the Dariusleut, Lehrerleut, and Schmiedeleut. Dariusleut and Lehrerleut colonies are located in both Alberta and Saskatchewan, and the Schmiedeleut are in Manitoba. Brethren were identified on population-based cancer registries of the three Prairie Provinces and among death registrations in the vital statistics of Alberta and Saskatchewan. The method of ascertainment was by a search for the 15 contemporary surnames and verification by address. 89 male and 91 female Brethren were identified who had cancer during the period, 1956--1975. The numbers of observed cancers were less than expected from provincial incidence rates for males and females in each province. The largest deficits were for female Brethren in Manitoba and Saskatchewan. There is a marked deficiency of cancer of the uterine cervix among female Brethren. In males there is a significant deficit of lung cancer. The Hutterite way of life contributes to a low risk for cancers of smoking-associated sites. However, there is evidence that male Brethren in Alberta may be at relatively increased risk for stomach cancer and leukemias. The site distribution patterns of cancers among the three endogamous leut are similar.

Importance of the male factor in cancer of the cervix

A woman's risk of cervical cancer is generally thought to be related to her sexual behaviour. The sexual background of her male partners is also important. In some societies, a woman's risk of cancer of the cervix will depend less on her own behaviour than on that of her partner. Male sexual behaviour, particularly in relation to prostitution, may account for two hitherto unexplained features of the epidemiology of this disease--the extremely high incidence in Latin America and the decline in mortality this century. If this is so and men carry the aetiological agent, it will be important to discover whether they do so for short or long periods.