Diet and the risk of in situ cervical cancer among white women in the United States.

A case-control study of women with incident in situ and invasive cervical cancer was conducted during 1982-83 in five US areas reporting to the Comprehensive Cancer Patient Data System: Birmingham, AL; Chicago, IL; Denver, CO; Miami, FL; and Philadelphia, PA. Controls were selected by random-digit dialing and matched to invasive cases on age, race, and telephone exchange. Of the white non-Hispanic in situ cases and controls identified, 229 (78 percent) and 502 (74 percent) were successfully interviewed. Diet was assessed by asking about the usual adult frequency of consumption of 75 food items and the use of vitamin supplements. Included were the major sources of the four micronutrients postulated to reduce the risk of cervical cancer: carotenoids, vitamin A, vitamin C, and folate. Weak inverse associations between risk of in situ disease and intake of carotenoids, vitamin C, folate, fruit, and vegetables/fruits were noted but, with further analysis, these seemed attributable to residual confounding by the multiple lifestyle-related risk factors for this disease and possibly to selection bias. Vitamin A and vegetable intake were unrelated to risk. Dark yellow-orange vegetable consumption and duration of multivitamin use were each strongly related to reduced risk of in situ disease (P for trend = 0.02 and 0.002, respectively) and need to be evaluated in other studies. The absence of persuasive protective effects for the four micronutrients and the similar findings from our analysis of invasive cervical cancer do not concur with other epidemiologic studies and suggest that the role of diet and nutrition in the etiology of cervical cancer is not yet resolved.

Diet and the risk of invasive cervical cancer among white women in the United States.

A case-control study of incident invasive cervical cancer was conducted in Birmingham, Alabama; Chicago, Illinois; Denver, Colorado; Miami, Florida; and Philadelphia, Pennsylvania, during 1982-1983. Controls were selected by random-digit dialing and were matched to cases by age, race, and telephone exchange. Of the white, non-Hispanic cases and controls identified, 271 (73%) and 502 (74%), respectively, were successfully interviewed. Diet was assessed by asking about the usual adult frequency of consumption of 75 food items and the use of vitamin supplements. Included were the major sources of the four micronutrients believed to reduce the risk of cervical cancer: carotenoids, vitamin A, vitamin C, and folate. Women in the highest quartiles of intake of each of these micronutrients had adjusted relative risks of invasive squamous cell cervical cancer comparable to those of women in the lowest quartiles, although their micronutrient intake was estimated to be 3-4 times as high. Risk was not affected by increased consumption of vegetables, dark green vegetables, dark yellow-orange vegetables, fruits, or legumes, or by high intake of the basic food groups. These generally negative findings stand in contrast to findings in previous epidemiologic studies, and the discrepancy is not readily explained by bias, uncontrolled confounding, or inadequate power. The question of the role of diet and nutrition in the etiology of cervical cancer is not yet resolved.

Barrier and spermicidal contraceptive methods and risk of invasive cervical cancer.

The effects of barrier and spermicidal methods of contraception on cervical cancer risk were examined by studying 479 cases of histologically confirmed invasive cervical cancer cases and 788 random digit dialing controls. In addition to a detailed history of contraceptive practices, information was available on numerous potential confounders, including demographic characteristics, sexual behavior, reproductive factors, Pap smear screening history, and smoking. After adjustment for relevant confounders, diaphragm and condom use were found not to be significantly associated with risk of cervical cancer. Although there was a small reduction in risk (OR = 0.8) associated with long-term use (5+ years) of the diaphragm, the effect appeared to relate to concomitant spermicide use, since there was evidence of further decreases in risk for women using spermicides alone for extended periods (OR = 0.7 for 5+ years). Effects were only seen among subjects of higher income and education levels, suggesting that patterns of usage may be important. The potential ability of spermicides to reduce cervical cancer risk by neutralizing viral agents warrants further attention.

PIP: A case-control study of cervical cancer and confounding factors barrier and spermicidal contraceptives, smoking, socio-economic status, and screening found that barrier methods confer no protection against cervical cancer, but spermicides may offer some protection. 479 cases diagnosed with invasive cervical cancer at 5 centers (Birmingham, Chicago, Denver, Miami and Philadelphia) and 788 community controls selected by random dialing were interviewed at home. Questions covered contraception, sociodemographics, pregnancies, menstruation, hygiene, sexual behavior, medical history, smoking, diet, marriage, and family history of cancer. 7 contraceptive methods, spermicides, diaphragm, condom, pill, IUD, female and male sterilization were analyzed. In unconditional logistic regression, at first barrier methods appeared to lower cancer risk. After controlling for age, race, education, income, last Pap smear, number of sex partners, barrier methods were not significant (odds ratio 1.2), with no significance in trend. Neither did duration of oral contraception or smoking alter the results. A slight insignificant decrease in risk was seen over time with diaphragm use. The odds ratio for vaginal spermicides was 1.0 with no trend for duration of use. For the small number of women reporting use of vaginal spermicides solely (11 cases and 29 controls) for 5 or more years, however, the odds ratio was 0.7 indicating protection against cervical cancer. The test for trend was not significant. Long-term users of spermicides were also less likely to develop cancer when ever-pill users were excluded from analysis. Analyzing only high socioeconomic groups, spermicide use gave an odds ratio of 0.5 for long-term use, and a significant trend for duration of use. Some explanations of these results were the possible protection of the whole vagina with spermicides compared to diaphragm or condom, and the potential use of larger quantities, or more consistent use of spermicides, by high socioeconomic groups of women. It is known that human papilloma virus may infects the penile shaft and that it can spread from the vagina to the cervix.

Risk factors for in situ cervical cancer: results from a case-control study.

A case-control study of 293 patients with in situ cervical cancer and 801 community controls was conducted between 1982 and 1984 in five geographic areas in the United States. Relative risk (RR) was elevated among women reporting multiple sexual partners (RR for greater than or equal to 5 partners = 5.0), a history of an abnormal Papanicolaou smear (RR = 5.0), interval since last Papanicolaou smear (RR for greater than or equal to 10-year interval versus 0- to 2-year interval = 4.1), use of oral contraceptives (RR for greater than or equal to 10 years use = 1.4), a history of nonspecific genital infection (RR = 2.6), and smoking (RR for current smokers = 1.9). Risk was low among diaphragm users (RR for greater than 2 years use = 0.5). Neither age at first coitus nor number of births was predictive of risk of in situ disease. Comparisons between this analysis and risk factors previously identified for invasive cervical cancer in this same study indicate that the risk factors were quite similar.

Sexual and reproductive risk factors for invasive squamous cell cervical cancer.

A case-control study of 418 women with invasive squamous cell cervical cancer and 704 population controls enabled evaluation of risk factors for this relatively rare cancer. Consistent with an infectious etiology was a pronounced effect of multiple sexual partners, with those reporting 10 or more partners being at a significant threefold excess risk. Early first intercourse also was associated with some residual effect on risk, although the relationship was not linear, nor the explanation readily apparent. Those with multiple births were at significantly elevated risks, even after adjustment for sexual parameters. Menstrual and hygiene factors, including use of tampons, vaginal deodorants, and douching products, were not consistently related to risk. Histories of specific infections involving the genital tract were poor predictors of risk, since few women provided positive responses, but those with nonspecific diseases were at a significant twofold excess risk.

Epidemiology of cervical cancer by cell type.

A multicenter case-control study of 481 invasive cervical cancer patients and 801 population controls enabled comparison of risk factors for squamous cell tumors (n = 418), adenosquamous cancers (n = 23), and adenocarcinomas (n = 40). The epidemiology of the squamous cell tumors resembled that found in other studies, with the major risk factors being absence of Pap smear screening (relative risk = 3.6 to 4.8 for those not screened within 5 yr), multiple sexual partners (relative risk = 2.9 for over ten partners), and history of genital infections or sores (relative risk = 2.3). Although based on small numbers, adenosquamous tumors appeared to share some of these risk factors, notably number of sexual partners, years since last Pap smear, and level of education. Adenocarcinomas were not similarly affected, although sexual practices were marginally predictive. Obesity increased the risk of adenocarcinoma, but no other similarities to endometrial adenocarcinoma were observed. Smoking was a significant predictor of squamous cell tumors but did not affect adenocarcinomas. Extended use of oral contraceptives was a risk factor for all tumor types, especially adenocarcinoma, and a familial tendency to cervical cancer was also observed for all cell types.

Long-term use of oral contraceptives and risk of invasive cervical cancer.

To evaluate the relationship between use of oral contraceptives and risk of invasive cervical cancer, a case-control study involving 479 patients and 789 population controls was undertaken in 5 geographic regions of the US. Initially, the relationship was obscured by confounding variables, particularly the interval since last Pap smear. Control for this variable as well as for sexual and sociodemographic factors revealed an RR of 1.5 overall, with long-term users (5 or more years) being at a 2-fold higher risk than non-users. Pill associations prevailed for both adenocarcinomas and squamous-cell tumors, and risks were highest for those using pills containing high estrogen potencies. In addition, there was some evidence that pill associations were most pronounced among women who had never used barrier methods of contraception or who had histories of genital infections, suggesting that oral contraceptives may act as co-carcinogens with transmissible agents. Our findings provide further evidence that long-term use of oral contraceptives may have a carcinogenic effect on cervical epithelium, but emphasize the need for careful evaluation of confounding influences.

Cigarette smoking and invasive cervical cancer.

A case-control study of 480 patients with invasive cervical cancer and 797 population controls, conducted in five geographic areas in the United States, included an evaluation of the relationship of several cigarette smoking variables to cervical cancer risk. Although smoking was correlated with both age at first intercourse and number of sexual partners, a significant smoking-related risk persisted for squamous cell carcinoma after adjustment for these factors (relative risk, 1.5). The risk of squamous cell cancers increased significantly with intensity and duration of smoking. Twofold excess risks were seen for those smoking 40 or more cigarettes per day and those smoking for 40 or more years. In addition, users of nonfilter cigarettes were at particularly high risk. Increased risks, however, were observed only among recent and continuous smokers. In contrast to squamous cell cancer, no relationship was observed between smoking and risk of adenocarcinoma or adenosquamous carcinoma (n = 63). These results suggest a causal relationship between cigarette smoking and invasive squamous cell cervical cancer, perhaps through a late-stage or promotional event, although the mechanisms of action require further elucidation.

Incidence and prevalence of eye cancer.

Cancer of the eye is the only ocular disease which directly threatens life. The average annual incidence rate (new cases) in the U.S. is about 1/100,000 population and the estimated prevalence rate (total cases) is about 12/100,000 population. With few exceptions, eye cancer occurs more frequently in whites than in blacks and more often in older than in younger people. The survival rate for persons with localized ocular tumors receiving early treatment is almost 80%. This statistic indicates the importance of optometric detection of this uncommon disease.

Primary health care - the role of optometry.

Optometrists, like all health care providers, should emphasize primary or preventive care. To provide this care optometrists must be aware of the risk factors for major causes of mortality. As an example, the risk profile for a white male age 45 to 49 years is given and discussed. Suggestions for primary vision care and detection of major risk factors by optometrists are also presented.