Kristine G. Wicklund

Body mass index, weight, and oral contraceptive failure risk.

OBJECTIVE: This project was supported by grant 1 R01 HD-34712 from the U.S. National Institute of Child Health and Human Development. To estimate the effect of body mass index (BMI) and weight on risk of pregnancy while using oral contraceptives (OCs). METHODS: We conducted a case-control study of 248 health maintenance organization enrollees who became pregnant while using OCs between 1998 and 2001 and 533 age-matched enrollees who were nonpregnant OC users during the same period. Using logistic regression we calculated adjusted odds ratios (ORs) to estimate the risk of pregnancy according to BMI and weight quartile. RESULTS: Among all OC users, when compared with women having a BMI of 27.3 or less, the risk of pregnancy was nearly 60% higher in women with BMI greater than 27.3 (OR 1.58, 95% confidence interval [CI] 1.11–2.24) and over 70% higher in women with BMI greater than 32.2 (OR 1.72, 95% CI 1.04–2.82). Among consistent users (women who missed no pills in reference month), the risk of pregnancy was more than doubled in women with BMI greater than 27.3 (OR 2.17, 95% CI 1.38–3.41) or BMI greater than 32.2 (OR 2.22, 95% CI 1.18–4.20). When compared with women weighing 74.8 kg or less, among consistent OC users the risk of pregnancy was over 70% higher in women weighing more than 74.8 kg (OR 1.71, 95% CI 1.08–2.71) and nearly doubled in women weighing more than 86.2 kg (OR 1.95, 95% CI 1.06–3.67). CONCLUSION: Our results suggest that being overweight may increase the risk of becoming pregnant while using OCs. If causal, this association translates to an additional 2–4 pregnancies per 100 woman-years of use among overweight women, for whom consideration of additional or effective alternative contraceptive methods may be warranted. LEVEL OF EVIDENCE: II-2

Re: Predictive Value of Symptoms for Early Detection of Ovarian Cancer

BACKGROUND A recent consensus statement encouraged use of certain symptoms to diagnose ovarian cancer earlier. We assessed the sensitivity, specificity, and positive predictive value of a proposed symptom index and of symptoms included in the consensus recommendation. METHODS In-person interviews were conducted with 812 case patients, aged 35-74 years, who had epithelial ovarian cancer that was diagnosed from January 1, 2002, through December 31, 2005, and with 1313 population-based control subjects. The symptom index was considered positive when pelvic or abdominal pain or bloating or feeling full was reported at least daily for at least 1 week, with an onset of less than 12 months before diagnosis or a reference date (for control subjects). The consensus criteria were considered fulfilled when any symptom above or urinary urgency or frequency was reported for at least 1 month, with an onset of less than 12 months before diagnosis or a reference date. Positive predictive value was calculated by use of external estimates of cancer prevalence. RESULTS Most case patients who had a positive index or met consensus criteria did so only within 5 months before diagnosis. Symptoms (except nausea) were somewhat less likely to have occurred among women diagnosed with early-stage than late-stage ovarian cancer. The estimated positive predictive value of the symptom index or symptoms meeting the consensus criteria was 0.6%-1.1% overall and less than 0.5% for early-stage disease. CONCLUSION Use of symptoms to trigger medical evaluation for ovarian cancer is likely to result in diagnosis of the disease in only one of 100 women in the general population with such symptoms.

Menopausal Hormone Therapy and Risk of Epithelial Ovarian Cancer

Substantial increase in the use of menopausal hormone therapy (HT) throughout the 1990s, followed by widespread discontinuation after the 2002 publication of the Womens Health Initiative findings, has resulted in large numbers of former HT users among U.S. women. However, few studies have examined whether ovarian cancer risk varies according to recency and duration of specific HT regimens. We assessed risk of epithelial ovarian cancer among users of unopposed estrogen (ET) and combined estrogen/progestogen (EPT). In a population-based study in Washington state, 812 women with ovarian cancer diagnosed in 2002 to 2005 and 1,313 controls were interviewed in person about the use of HT and other characteristics. Women who used a single form of therapy (ET or EPT) were compared with women who never used HT using logistic regression to calculate odds ratios (OR) and 95% confidence intervals (95% CIs). Risk was increased among current or recent (within the last 3 years) users of ET with ≥5 years of use (ORs, 95% CIs: 1.6, 1.1-2.5 and 1.8, 0.8-3.7, respectively). Little increase in risk was noted among long-term ET users who discontinued use in the more distant past (OR, 1.2; 95% CI, 0.6-2.6). No increase in risk was noted among women who used only EPT, regardless of duration. Compared with women who never used HT, current users of EPT had an OR of 1.1 (95% CI, 0.8-1.5), and risk declined with increasing time since stopping; the OR was 0.7 (95% CI, 0.4-1.0) among women who had discontinued EPT within the last 3 years and 0.5 (95% CI, 0.3-0.7) among women who stopped at an earlier point. Long-term ET may be associated with an increased ovarian cancer risk that wanes after use ceases. We did not observe an increased risk with EPT, and with increasing time after stopping, a reduction in risk became increasingly evident. The progestogen component of HT may confer a risk reduction that is masked by an opposing effect of estrogen until, among former users, estrogenic influences have diminished. These findings, if replicated, may have implications both for public health and development of chemoprevention strategies. (Cancer Epidemiol Biomarkers Prev 2007;16(12):2548–56)

Risk of papillary thyroid cancer in women in relation to smoking and alcohol consumption

Both smoking and alcohol consumption may influence thyroid function, although the nature of these relations is not well understood. We examined the influence of tobacco and alcohol use on risk of papillary thyroid cancer in a population-based case-control study. Of 558 women with thyroid cancer diagnosed during 1988-1994 identified as eligible, 468 (83.9%) were interviewed; this analysis was restricted to women with papillary histology (N = 410). Controls (N = 574) were identified by random digit dialing, with a response proportion of 73.6%. We used logistic regression to calculate odds ratios (OR) and associated confidence intervals (CI) estimating the relative risk of papillary thyroid cancer associated with cigarette smoking and alcohol consumption. A history of ever having smoked more than 100 cigarettes was associated with a reduced risk of disease (OR = 0.7, 95% CI = 0.5-0.9). This reduction in risk was most evident in current smokers (OR = 0.5, 95% CI = 0.4-0.7). Women who reported that they had ever consumed 12 or more alcohol-containing drinks within a year were also at reduced risk (OR 0.7, 95% CI = 0.5-1.0). Similar to the association noted with smoking, the reduction in risk was primarily present among current alcohol consumers. The associations we observed, if not due to chance, may be related to actions of cigarette smoking and alcohol consumption that reduce thyroid cell proliferation through effects on thyroid stimulating hormone, estrogen, or other mechanisms.

Coffee, tea, colas, and risk of epithelial ovarian cancer.

Associations of coffee, tea, and other caffeinated beverages with ovarian cancer risk remain uncertain. In a population-based study in Washington State, 781 women with epithelial ovarian cancer diagnosed in 2002 to 2005 and 1,263 controls completed self-administered questionnaires detailing consumption of caffeinated and noncaffeinated coffee, teas, and colas and in-person interviews regarding reproductive and hormonal exposures. We assessed risk associated with coffee, tea, and cola drinking and with total caffeine consumption using logistic regression to calculate odds ratios and 95% confidence intervals. Neither caffeinated nor decaffeinated coffees were associated with ovarian cancer risk; also, we observed no association of total caffeine with risk using a combined index that summed intake from coffee, tea, and carbonated soft drinks. Among teas, neither herbal/decaffeinated nor black teas were associated with risk; however, women who reported drinking ≥1 cup/d of green tea had a 54% reduction in risk (Ptrend = 0.01). Associations of green tea with risk were similar when invasive and borderline cases were considered separately and when Asian women were excluded from analysis. Green tea, which is commonly consumed in countries with low ovarian cancer incidence, should be further investigated for its cancer prevention properties. (Cancer Epidemiol Biomarkers Prev 2008;17(3):712–6)

Nightshift work and risk of ovarian cancer

Objectives Animal evidence suggests that circadian disruption may be associated with ovarian cancer, though very little epidemiological work has been done to assess this potential association. We evaluated the association between self-reported nightshift work, a known circadian disruptor, and ovarian cancer in a population-based case-control study. Methods The study included 1101 women with invasive epithelial ovarian cancer, 389 women with borderline epithelial ovarian tumours and 1832 controls and was conducted in western Washington state. Shift work data were collected as part of inperson interviews. Results Working the nightshift was associated with an increased risk of invasive (OR=1.24, 95% CI 1.04 to 1.49) and borderline (OR=1.48, 95% CI 1.15 to 1.90) tumours; however, we observed little evidence that risks increased with increasing cumulative duration of nightshift work, and risks were not elevated in the highest duration category (>7 nightshift work-years). Increased risks were restricted to women who were 50 years of age and older and to serous and mucinous histologies of invasive and borderline tumours. There was suggestive evidence of a decreased risk of ovarian cancer among women reporting a preference for activity during evenings rather than mornings. Conclusions We found evidence suggesting an association between shift work and ovarian cancer. This observation should be followed up in future studies incorporating detailed assessments of diurnal preference (ie, chronotype) in addition to detailed data on shift schedules.

Use of Exogenous Hormones and Risk of Papillary Thyroid Cancer (Washington, United States)

Objectives: Greater incidence of thyroid cancer in women than men, particularly evident during the reproductive years, has led to the suggestion that female hormones may increase risk of this disease. We conducted a population-based case-control study in women aged 18 to 64 years in three counties of western Washington State (United States) to assess the relation of use of exogenous hormones, including oral contraceptives (OC) and hormone replacement therapy (HRT), to risk of papillary thyroid cancer.Methods: Of 558 women with thyroid cancer of the follicular epithelium diagnosed during 1988-94 who were identified as eligible, 468 (83.9 percent) were interviewed; this analysis was restricted to women with papillary histology (n = 410). Controls (n = 574) were identified by random digit dialing, with a response proportion of 73.6 percent. Logistic regression was used to calculate odds ratios (OR) and associated 95 percent confidence intervals (CI) estimating the relative risk of papillary thyroid cancer among users of exogenous hormones.Results: Among women aged 45 to 64 years, we observed no association of use of OCs or HRT with risk of papillary thyroid cancer. Among women less than 45 years of age, risk of papillary thyroid cancer was reduced in women who had ever used OCs (OR = 0.6, CI = 0.4-0.9); beyond the relation with ever-use, there was no further association with specific aspects of exposure such as estrogenic potency, latency, recency, age at first or last use, or use at the reference date.Conclusions: Our data do not support the hypothesis that use of exogenous estrogens increases the risk of female thyroid cancer. Cancer Causes and Control 1998, 9, 341-349

Analgesic drug use and risk of epithelial ovarian cancer.

Analgesic use may reduce ovarian cancer risk, possibly through antiinflammatory or antigonadotropic effects. The authors conducted a population-based, case-control study in Washington State that included 812 women aged 35-74 years who were diagnosed with epithelial ovarian cancer between 2002 and 2005 and 1,313 controls. Use of analgesics, excluding use within the previous year, was assessed via in-person interviews. Logistic regression was used to calculate odds ratios and 95% confidence intervals. Overall, acetaminophen and aspirin were associated with weakly increased risks of ovarian cancer. These associations were stronger after more than 10 years of use (acetaminophen: odds ratio (OR) = 1.8, 95% confidence interval (CI): 1.3, 2.6; aspirin: OR = 1.6, 95% CI: 1.1, 2.2) and were present for indications of headache, menstrual pain, and other pain/injury. Reduced risk was observed among aspirin users who began regular use within the previous 5 years (OR = 0.6, 95% CI: 0.4, 1.0) or used this drug for prevention of heart disease (OR = 0.7, 95% CI: 0.5, 1.0). These results, in the context of prior findings, do not provide compelling evidence of a true increase in risk of ovarian cancer among women who use these drugs. However, they add to the weight of evidence that, in the aggregate, provides little support for the use of analgesic drugs as chemoprevention for this disease.

Recreational physical activity and risk of epithelial ovarian cancer.

BackgroundPhysical activity may influence ovarian cancer risk through hormonal, inflammatory, or immune-mediated processes or by suppressing ovulation. In a population-based case–control study of epithelial ovarian cancer, we assessed risk associated with recreational physical activity with a focus on characterizing risk within histologic subtypes.MethodsInformation was collected during in-person interviews with 812 women with ovarian cancer diagnosed in western Washington State from 2002–2005 and 1,313 controls. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Exercise was assessed according to the average hours and metabolic equivalent (MET)-hours per week and the number of years in which regular recreational activity occurred.ResultsRelative to women who reported no regular exercise throughout adulthood, the overall risk of invasive, but not borderline, ovarian cancer was reduced among more active women. Reductions in risk of invasive disease were most evident among women with the greatest frequency of high-intensity activity during adulthood. For serous invasive cancer, women in the uppermost category of MET-hours per week of recreational activity in adulthood had 60% the risk of inactive women (95% CI 0.4–0.9), whereas this level of activity was associated with more than a doubling in risk of endometrioid and clear cell invasive tumors.ConclusionsOur findings are compatible with an overall reduction in risk of invasive epithelial ovarian cancer associated with recreational activity but suggest that this association may differ in women with different histologic types of disease. Inconsistent findings across studies that have considered histologic type indicate that this issue is not yet resolved.

Recreational physical activity and risk of papillary thyroid cancer (United States)

Objective: Exercise has been hypothesized to influence cancer risk through a variety of mechanisms including hormonal, metabolic and immunologic effects, yet its relation with the risk of thyroid cancer has not been examined. We conducted a population-based case–control study in women aged 18–64 in three counties of western Washington State to assess the relation of recreational physical activity with risk of papillary thyroid cancer. Methods: Of 558 women with thyroid cancer of the follicular epithelium diagnosed during 1988–1994 who were identified as eligible, 468 (83.9%) were interviewed; this analysis was restricted to women with papillary histology (n = 410). Controls (n = 574) were identified by random digit dialing, with a response proportion of 73.6%. Logistic regression was used to calculate odds ratios (OR) and associated confidence intervals (CI) estimating the relative risk of papillary thyroid cancer associated with various aspects of recreational exercise. Results: Risk of thyroid cancer was reduced among women who reported that they engaged in regular recreational exercise during the 2 years before diagnosis relative to women who did not report exercise during that time period (OR = 0.76, 95% CI 0.59–0.98). A similar risk reduction was noted among women who reported having exercised regularly between ages 12 and 21 (OR = 0.83, 95% CI 0.64–1.1). However, no clear associations with aspects of recreational activity, including average hours exercised per week or weekly energy expenditure, were observed. Conclusions: These results provide some initial support for the hypothesis that physical activity may reduce risk of thyroid cancer.