Body mass index in relation to ovarian cancer: a multi-centre nested case-control study

Anthropometric factors and the risk of ovarian cancer: A systematic review and meta-analysis

BACKGROUND

Excess weight is convincingly associated with several cancers, but the association with ovarian cancer is insufficiently clarified, in particular regarding subgroups defined by menopausal status and ovarian cancer histologic type.

AIMS

We carried out a comprehensive systematic review and meta-analysis of overweight and obesity in relation to ovarian cancer with focus on different subgroups.

METHODS AND RESULTS

We searched PubMed and Web of Science for relevant cohort and case-control studies published from inception to June 2021 in English language and using a clear definition of overweight and obesity. We combined maximally adjusted risk estimates using a random effects model. We analyzed data from 15 cohort and 26 case-control studies, including 28 471 ovarian cancer cases. The relative risk of ovarian cancer for overweight and obesity was 1.06 (95% confidence interval [CI] = 1.00-1.12) and 1.19 (95% CI = 1.11-1.28), respectively. Among premenopausal women, increased ovarian cancer risk was noted for overweight (RR 1.34; 95% CI = 1.03-1.75) and obesity (RR 1.51; 95% CI = 1.21-1.88). By comparison, among postmenopausal women no statistically significant association was found for overweight (RR 1.00; 95% CI 0.87-1.14) and obesity (RR1.03; 95% CI = 0.82-1.31). Increased risk was found for mucinous (RR 1.44; 95% CI = 1.03-2.01) and clear cell (RR 1.82; 95% CI = 1.11-2.99) ovarian cancer subtypes, but not for serous (RR1.12; 95% CI = 0.84-1.50;) and endometroid subtypes (RR1.24; 95% CI =0.96-1.60).

CONCLUSIONS

Obesity is associated with increased ovarian cancer risk. That relation is largely due to a positive association between adiposity and ovarian cancer among premenopausal but not postmenopausal women and among cases with mucinous and clear cell but not serous or endometrioid histology.

Obesity and ovarian cancer risk: A systematic review

The association between obesity and ovarian cancer risk has been extensively investigated, but studies have yielded inconsistent findings. This review aims to summarise and discuss the evidence generated to date. Articles published in English prior to August 2016 were retrieved from PubMed. Keywords included obesity, overweight, body size, body mass index, waist-hip ratio, waist circumference, body weight, ovarian cancer, ovarian carcinoma, ovarian neoplasm, and ovarian tumour. Eligible studies compared two or more groups of women, with at least one group in the overweight or obese category and one comprising normal weight controls. Summary data in the form of relative risk, hazard ratio, or odds ratio for each comparison group from individual studies were collated and reviewed. Forty-three studies were included in the final analysis, with a total of 3,491,943 participants. All studies included body mass index as an exposure measure, and a majority relied on self-reported measures from participants; 14 studies found a statistically significant positive association between ovarian cancer risk and higher body mass index, 26 studies found no significant association, and 3 studies found a negative association between ovarian cancer risk and higher body mass index. This review concludes that there is limited, inconsistent evidence of a positive association between obesity and ovarian cancer risk.

Plasma alkylresorcinols, biomarkers of whole-grain wheat and rye intake, and risk of type 2 diabetes in Scandinavian men and women

BACKGROUND

Studies that use dietary biomarkers to investigate the association between whole-grain intake and the risk of developing type 2 diabetes (T2D) are lacking.

OBJECTIVE

We examined the association between plasma total alkylresorcinols and the alkylresorcinol C17:0-to-C21:0 ratio, biomarkers of whole-grain wheat and rye intake and relative whole-grain rye over whole-grain wheat intake, respectively, and the risk of T2D among Scandinavian men and women.

DESIGN

A nested case-control study was established within the Northern Sweden Health and Disease Study and the Danish Diet, Cancer and Health cohort. Alkylresorcinol concentrations and the ratios of C17:0 to C21:0 were determined in plasma samples from 931 case-control pairs. ORs for T2D were calculated for plasma total alkylresorcinol concentration or C17:0-to-C21:0 ratio in quartiles with the use of conditional logistic regression that was adjusted for potential confounders. Additional analyses with whole-grain wheat and rye intake estimated from food-frequency questionnaires (FFQs) as exposures were also performed.

RESULTS

The plasma total alkylresorcinol concentration was not associated with T2D risk (OR: 1.34; 95% CI: 0.95, 1.88) for the highest compared with the lowest quartiles in multivariable adjusted models. However, the C17:0-to-C21:0 ratio was associated with a lower diabetes risk (OR: 0.54; 95% CI: 0.37, 0.78). Analyses with whole-grain intake estimated from FFQs yielded similar results.

CONCLUSIONS

Total whole-grain wheat and rye intake, reflected by alkylresorcinols in plasma, was not associated with a lower risk of T2D in a population with high whole-grain intake. In contrast, the proportion of whole-grain rye to whole-grain wheat intake, indicated by the plasma C17:0-to-C21:0 ratio, was inversely associated with T2D. This suggests that whole-grain intake dominated by rye may be favorable for T2D prevention.

Anthropometric factors and ovarian cancer risk: a systematic review and nonlinear dose-response meta-analysis of prospective studies

In the World Cancer Research Fund/American Institute for Cancer Research report from 2007 the evidence relating body fatness to ovarian cancer risk was considered inconclusive, while the evidence supported a probably causal relationship between adult attained height and increased risk. Several additional cohort studies have since been published, and therefore we conducted an updated meta-analysis of the evidence as part of the Continuous Update Project. We searched PubMed and several other databases up to 20th of August 2014. Summary relative risks (RRs) were calculated using a random effects model. The summary relative risk for a 5-U increment in BMI was 1.07 (95% CI: 1.03-1.11, I(2) = 54%, n = 28 studies). There was evidence of a nonlinear association, pnonlinearity  < 0.0001, with risk increasing significantly from BMI∼28 and above. The summary RR per 5 U increase in BMI in early adulthood was 1.12 (95% CI: 1.05-1.20, I(2) = 0%, pheterogeneity = 0.54, n = 6), per 5 kg increase in body weight was 1.03 (95% CI: 1.02-1.05, I(2) = 0%, n = 4) and per 10 cm increase in waist circumference was 1.06 (95% CI: 1.00-1.12, I(2) = 0%, n = 6). No association was found for weight gain, hip circumference or waist-to-hip ratio. The summary RR per 10 cm increase in height was 1.16 (95% CI: 1.11-1.21, I(2) = 32%, n = 16). In conclusion, greater body fatness as measured by body mass index and weight are positively associated risk of ovarian cancer, and in addition, greater height is associated with increased risk. Further studies are needed to clarify whether abdominal fatness and weight gain is associated with risk.

Is body size associated with ovarian cancer in southern Chinese women?

PURPOSE

To investigate the association between risk of ovarian cancer and body size among southern Chinese women.

METHODS

A hospital-based case-control study was undertaken in Guangzhou, Guangdong Province, from 2006 to 2008. Participants were 500 incident ovarian cancer patients and 500 controls, with a mean age of 59 years. Information on adult height and weight was obtained via face-to-face interview using a structured questionnaire. Logistic regression analyses were performed to assess the association between anthropometric factors and the ovarian cancer risk.

RESULTS

Compared with women having body weight ≤50 kg and body mass index (BMI) <18.5 kg/m(2), the adjusted odds ratios (ORs) of ovarian cancer were 1.84 (95 % confidence interval (CI) 1.34-2.54) and 1.77 (95 % CI 1.04-3.02) in those women who had body weight >55 kg and BMI ≥23 kg/m(2), respectively. Significant dose-response relationships were also observed for both weight and BMI (p < 0.01). Body height was not significantly associated with ovarian cancer risk.

CONCLUSION

Body weight and BMI were associated with increased risk of ovarian cancer in southern Chinese women.

Height and site-specific cancer risk: A cohort study of a korean adult population

To evaluate the association between height and risk of cancer in an East Asian, middle-income population, the authors followed up a cohort of 788,789 Koreans (449,214 men and 339,575 women) aged 40-64 years for cancer incidence between 1994 and 2003. Cox proportional hazards regression analysis was used to evaluate the association. Each 5-cm increment in height was associated with 5% and 7% higher risk of all-sites cancer in men and women, respectively, after adjustment for age, body mass index, and behavioral and socioeconomic factors. When the associations were evaluated for site-specific cancers, a positive association was observed for cancer of the colon and thyroid in both men and women. Among gender-specific cancers, prostate cancer was positively associated with height in men. In women, there was a positive association between height and cancers of the breast and ovary, which did not change even after additional adjustment for reproductive factors. Although more clarification is needed for some site-specific cancers, the same positive association of height with cancer in a middle-income Korean population as found in high-income Western populations supports the influence of early life environment on cancer development in adulthood.

Epidemiology of ovarian cancer

Ovarian cancer represents the sixth most commonly diagnosed cancer among women in the world, and causes more deaths per year than any other cancer of the female reproductive system. Despite the high incidence and mortality rates, the etiology of this disease is poorly understood. Established risk factors for ovarian cancer include age and having a family history of the disease, while protective factors include increasing parity, oral contraceptive use, and oophorectomy. Lactation, incomplete pregnancies, and surgeries such as hysterectomy and tubal ligation may confer a weak protective effect against ovarian cancer. Infertility may contribute to ovarian cancer risk among nulliparous women. Other possible risk factors for ovarian cancer include postmenopausal hormone-replacement therapy and lifestyle factors such as cigarette smoking and alcohol consumption. Many of the causes of ovarian cancer are yet to be identified. Additional research is needed to better understand the etiology of this deadly disease.

Body size in early life and risk of epithelial ovarian cancer: results from the Nurses' Health Studies

Adult body mass index (BMI) has been associated with ovarian cancer risk, but few studies have examined body size earlier in life. We prospectively examined associations of body fatness at ages 5 and 10, BMI at age 18, height, and birthweight with risk of epithelial ovarian cancer in the Nurses' Health Study (NHS: 110 311 women, 735 cases) and Nurses' Health Study II (NHSII: 113 059 women, 137 cases). Cox proportional hazards regression was used to estimate relative risks (RRs) and 95% confidence intervals (CIs). There was a weak inverse association between average body fatness at ages 5 and 10 and risk in the NHS (RR for heaviest vs most lean=0.81, 95% CI: 0.53-1.24, P for trend=0.04) and a nonsignificant positive association in the NHSII (RR=2.09, 95% CI: 0.98-4.48, P for trend=0.10), possibly due to differences in age and menopausal status. Height was positively associated with risk in both cohorts (RR for >or=1.75 vs <1.6 m=1.43, 95% CI: 1.05-1.96, P for trend=0.001). Body mass index at the age of 18 years and birthweight were not associated with risk. Further research should examine the biological mechanisms underlying the observed associations.

Obesity and gynaecological cancer

Obesity is now considered to be a global epidemic. The problem of obesity has significant implications for the diagnosis and treatment of gynaecological cancer. The cancer most frequently associated with obesity is that of the endometrium. The risk of endometrial cancer is 2-3 times higher in overweight and obese women. Obesity also adversely affects survival in most studies. With regard to ovarian cancer the evidence is inconsistent. Obesity in young adulthood may be more important than that in later life. With regard to survival obesity has an adverse effect but not in early stage disease. Few data are available regarding cervical cancer and obesity. There is evidence that obesity is associated with adenocarcinoma rather than squamous carcinoma. Data on vulval cancer and obesity are scant.

DNA repair gene ERCC2 polymorphisms and associations with breast and ovarian cancer risk

Breast and ovarian cancers increased in the last decades. Except rare cases with a genetic predisposition and high penetrance, these pathologies are viewed as a polygenic disease. In this concept, association studies look for genetic variations such as polymorphisms in low penetrance genes, i.e. genes in interaction with environmental factors. DNA repair systems that protect the genome from deleterious endogenous and exogenous damages have been shown to have significantly reduced. In particular, enzymes of the nucleotide excision repair pathway are suspected to be implicated in cancer. In this study, 2 functional polymorphisms in a DNA repair gene ERCC2 were analyzed. The population included 911 breast cancer cases, 51 ovarian cancer cases and 1000 controls. The genotyping of 2 SNP (Single Nucleotide Polymorphism) was carried out on the population with the MGB (Minor Groove Binder) probe technique which consists of the use of the allelic discrimination with the Taqman^® method. This study enabled us to show an increase in risk of breast cancer with no oral contraceptive users and with women exhibiting a waist-to-hip ratio (WHR) > 0.85 for Asn homozygous for ERCC2 312.

Height, body mass index, and ovarian cancer: a pooled analysis of 12 cohort studies

BACKGROUND

Although many studies have investigated the association between anthropometry and ovarian cancer risk, results have been inconsistent.

METHODS

The associations of height, body mass index (BMI), and ovarian cancer risk were examined in a pooled analysis of primary data from 12 prospective cohort studies from North America and Europe. The study population consisted of 531,583 women among whom 2,036 epithelial ovarian cancer cases were identified. To summarize associations, study-specific relative risks (RR) were estimated using the Cox proportional hazards model and then combined using a random-effects model.

RESULTS

Women with height > or =1.70 m had a pooled multivariate RR of 1.38 [95% confidence interval (95% CI), 1.16-1.65] compared with those with height <1.60 m. For the same comparison, multivariate RRs were 1.79 (95% CI, 1.07-3.00) for premenopausal and 1.25 (95% CI, 1.04-1.49) for postmenopausal ovarian cancer (P(interaction) = 0.14). The multivariate RR for women with a BMI > or =30 kg/m(2) was 1.03 (95% CI, 0.86-1.22) compared with women with a BMI from 18.5 to 23 kg/m(2). For the same comparison, multivariate RRs were 1.72 (95% CI, 1.02-2.89) for premenopausal and 1.07 (95% CI, 0.87-1.33) for postmenopausal women (P(interaction) = 0.07). There was no statistically significant heterogeneity between studies with respect to height or BMI. BMI in early adulthood was not associated with ovarian cancer risk.

CONCLUSION

Height was associated with an increased ovarian cancer risk, especially in premenopausal women. BMI was not associated with ovarian cancer risk in postmenopausal women but was positively associated with risk in premenopausal women.

Risk factors for ovarian cancer: an overview with emphasis on hormonal factors

Ovarian cancer is the fifth most frequently occurring cancer among women and leading cause of gynecological cancer deaths in North America. Although the etiology of ovarian cancer is not clear, certain factors are implicated in the etiology of this disease, such as ovulation, gonadotropic and steroid hormones, germ cell depletion, oncogenes and tumor suppressor genes, growth factors, cytokines, and environmental agents. Family history of breast or ovarian cancer is a prominent risk factor for ovarian cancer, with 5-10% of ovarian cancers due to heritable risk. Reproductive factors such as age at menopause and infertility contribute to greater risk of ovarian cancer, whereas pregnancy, tubal ligation, and hysterectomy reduce risk. Oral contraceptive (OC) use has clearly been shown to be protective against ovarian cancer. In contrast, large epidemiologic studies found hormone replacement therapy (HRT) to be a greater risk factor for ovarian cancer. The marked influence of hormones and reproductive factors on ovarian cancer suggests that endocrine disrupters may impact risk; however, there is a notable lack of research in this area. Lifestyle factors such as cigarette smoking, obesity, and diet may affect ovarian cancer risk. Exposure to certain environmental agents such as talc, pesticides, and herbicides may increase risk of ovarian cancer; however, these studies are limited. Further research is needed to strengthen the database of information from which an assessment of environmental and toxicological risk factors for ovarian cancer can be made.

Obesity and the risk of epithelial ovarian cancer: a systematic review and meta-analysis

Obesity is a risk factor for several hormone-related cancers but evidence for an effect on risk of epithelial ovarian cancer remains inconclusive. Many studies evaluating this association have had insufficient statistical power to detect modest effects, particularly for histological subtypes of ovarian cancer. We have therefore assembled the published evidence on obesity and ovarian cancer in a systematic literature review and meta-analysis. We identified eligible studies using Medline and manual review of retrieved references, and included all population-based studies that assessed the association between overweight, body mass index (BMI25-29.9) and obesity (BMI30) and histologically confirmed ovarian cancer. Meta-analysis was restricted to those studies that expressed effect as an odds ratio (OR), risk ratio, or standardised incidence ratio and 95% confidence interval (CI). We identified 28 eligible studies, of which 16 on adult obesity and 9 on obesity in early adulthood were suitable for meta-analysis. Overall, 24 of 28 studies reported a positive association between obesity and ovarian cancer, and in 10 this reached statistical significance. The pooled effect estimate for adult obesity was 1.3 (95%CI1.1-1.5) with a smaller increased risk for overweight (OR1.2;95%CI1.0-1.3). The pooled OR was stronger among case-control studies (OR=1.5) than cohort studies (OR=1.1). Overweight/obesity in early adulthood was also associated with an increased risk of ovarian cancer. There was no evidence that the association varied for the different histological subtypes of ovarian cancer. Ovarian cancer should be added to the list of cancers likely to be related to obesity.

Co-twin control and cohort analyses of body mass index and height in relation to breast, prostate, ovarian, corpus uteri, colon and rectal cancer among Swedish and Finnish twins

Associations between anthropometric measures and cancer have been studied previously, but relatively few studies have had the opportunity to control for genetic and early shared environmental factors. In this study, we analyzed 2 twin cohorts from Sweden born 1886-1925 (n = 21,870) and 1926-1958 (n = 30,279) and 1 from Finland born 1880-1958 (n = 25,882) including in total 78,031 twins, and studied the association between BMI and height and risk of prostate, breast, ovarian, corpus uteri, colon and rectal cancer. The cohorts were both analyzed through a co-twin control method and as traditional cohorts. In co-twin control analyses, older obese (BMI > or = 30 kg/m(2)) subjects (median age 56 years at baseline) were at higher risk of cancer of the corpus uteri (OR = 3.0; 95% CI 0.9-10.6), colon (OR = 1.9; 95% CI 0.8-4.5) and breast (OR = 2.5; 95% CI 1.3-4.2). For younger obese women (median age 30 years at baseline), an inverse tendency was observed for breast cancer (OR = 0.6; 95% CI 0.3-1.5, p for trend = 0.05). The tallest women had an increased risk of breast (OR = 1.8; 95% CI 1.3-2.7) and ovarian cancer (OR = 1.7; 95% CI 0.8-3.5). No consistent associations were found for prostate cancer either for BMI or height. There are some suggestions in our study that uncontrolled genetic or early shared environmental factors may affect risk estimates in studies of anthropometric measures and cancer risk, but do not explain observations of increased cancer risks related to BMI or height.

Endogenous androgens and risk of epithelial ovarian cancer: results from the European Prospective Investigation into Cancer and Nutrition (EPIC)

Few epidemiologic studies have examined the hypothesis that circulating androgens are involved in the development of ovarian cancer. We investigated the association between prediagnostic serum levels of androgens and sex hormone-binding globulin (SHBG) and ovarian cancer risk in a case-control study nested within the European Prospective Investigation into Cancer and Nutrition cohort. One hundred and ninety-two ovarian cancer cases and 346 matched controls not using exogenous hormones at baseline blood donation were eligible for the study. Serum levels of testosterone, androstenedione, dehydroepiandrosterone sulfate, and SHBG were measured by direct immunoassays. Free testosterone (fT) was calculated according to mass action laws. Multivariate conditional logistic regression was used to estimate odds ratios adjusted for possible confounders. Overall, there was no association between serum concentrations of androgens or SHBG and ovarian cancer risk. In postmenopausal women, fT concentrations were inversely related to risk [highest versus lowest tertile odds ratio 0.45 (0.24-0.86); P(trend) = 0.01]. Among women diagnosed before the age of 55 years, there was a negative association with SHBG and a positive association with fT and ovarian cancer risk, although these associations were not statistically significant. The present study suggests that circulating androgens and SHBG levels are not strongly associated with ovarian cancer risk, although levels of fT may be associated with an increased risk among women diagnosed at relatively young age. The heterogeneity of results on the associations of fT with ovarian cancer risk in postmenopausal women deserves further investigation.

Weight, Height, and Body Mass Index and Risk for Ovarian Cancer in a Cohort Study

PURPOSE

Reported associations between ovarian cancer and body size are inconsistent. We assessed ovarian cancer and anthropometry in the Breast Cancer Detection Demonstration Project Follow-Up Study.

METHODS

The 46,026 participants completed a baseline interview and mailed questionnaires between 1979 and 1998. By using multiple sources, we identified 346 incident ovarian cancers during follow-up. We calculated rate ratios (RRs) and 95% confidence intervals (CIs) to estimate relative risks for developing ovarian cancer associated with height and weight (measured 1973 to 1980) and self-reported current and usual adult weight (collected during follow-up).

RESULTS

Neither taller height (> or =66 versus <62 inches; RR, 0.90; 95% CI, 0.64-1.26) nor greater weight (> or =161 versus < or =120 lbs; RR, 1.09; 95% CI, 0.77-1.55) was associated with ovarian cancer. Compared with normal weight (body mass index [BMI], 18.5 to 24.9 kg/m(2)), overweight (BMI, 25 to 29.9 kg/m(2); RR, 1.00; 95% CI, 0.78-1.29) and obesity (BMI, 30 to 34.9 kg/m(2); RR, 0.94; 95% CI, 0.59-1.48) were not associated with ovarian cancer. Severe obesity (BMI > or = 35 kg/m(2)) produced a nonsignificantly elevated RR (1.55; 95% CI, 0.84-2.84). Associations with histologic types and statistical interactions with menopausal status and hormone therapy use were null.

CONCLUSIONS

Based on height and weight measured before baseline, overweight and obesity were not significantly associated with ovarian cancer in this cohort.

Risk of ovarian cancer associated with BMI varies by menopausal status

Obesity has been linked to increased risk of several malignancies, but the role of obesity in the etiology of ovarian cancer remains unclear. Therefore, a hospital-based case-control study was conducted to investigate the association between body size and risk of ovarian cancer. Participants included 427 women with primary, incident ovarian cancer and 854 cancer-free controls. All participants received medical services at Roswell Park Cancer Institute in Buffalo, NY between 1982 and 1998 and completed a comprehensive epidemiological questionnaire. The instrument included questions regarding height and usual wt prior to survey. Participants were classified as underweight/normal (BMI < or = 24.9 kg/m2), overweight (BMI 25.0-29.9 kg/m2), or obese (BMI > or = 30.0 kg/m2). Compared with underweight/normal participants, being overweight (adjusted odds ratio [OR] = 1.02; 95% CI 0.77-1.36) or obese (adjusted OR = 1.17; 95% CI 0.84-1.65) was not significantly associated with an elevated risk of ovarian cancer. After stratification by menopausal status, BMI showed no significant association to ovarian cancer risk among postmenopausal women (> or = 50 y old). However, among premenopausal women (<50 y old), those classified as obese had a significantly increased risk (adjusted OR = 2.19; 95% CI 1.19-4.04) compared with women classified as normal/underweight. These findings suggest a potential influence of menopausal status on the total endogenous hormonal environment, including estrogens, androgens, and insulin-like growth factors, when considering the association between body size and ovarian cancer risk. In light of the fact that obesity is a modifiable risk factor, further investigation on this topic is warranted.

Dietary intake changes and their association with ovarian cancer risk

There are reasons to suspect that dietary changes through adult life may modify risk for some cancers. We examined the association of recent and past dietary habits and changes in dietary intake over time with ovarian cancer risk. Long-term nutritional assessment was performed retrospectively in 631 incident cases of invasive epithelial ovarian cancer and in 1174 matched controls (matched by age +/- 2 y, country of origin, and period of immigration) as part of a nationwide case-control study of ovarian cancer conducted between the years of 1994 and 1996 in Israel. Using a 2-step quantified Food Frequency Questionnaire, participants were first asked about their consumption of food items 1 y prior to the interview, and then whether their consumption had changed over time. The time of the change and consumption level before the change were recorded, allowing reconstruction of daily intakes for several time points. The reported mean percentage of animal fat intake decreased by 1.3% in cases but by 1.9% in controls (P for difference = 0.003). Conditional multivariate logistic regression was used to estimate odds ratios adjusted for total energy, parity, and oral contraceptive use. Substituting nonanimal fat in preference to animal fat over a relatively short term (between 2 and 7 y prior to interview) decreased the risk of ovarian cancer [OR = 0.65/100 kcal (418.4 kJ), 95% CI = 0.50 - 0.85]. Our results suggest that substitution of nonanimal for animal fat during adult life might reduce the risk of ovarian cancer, but this requires confirmation in prospective studies.

Body Size and Risk of Epithelial Ovarian Cancer (United States)

OBJECTIVE

We conducted a population-based case-control study of epithelial ovarian cancer in relation to measures of body size and adult weight change. In particular, we sought to characterize the independent relation of body weight at particular ages with risk.

METHODS

In-person interviews were sought with 35-54 year-old female residents of metropolitan Atlanta, Seattle or Detroit diagnosed with ovarian cancer during 1994-1998, and with controls sampled from these populations. Information provided by 355 cases and 1,637 controls was analyzed using unconditional logistic regression.

RESULTS

The risk among women in the top tenth, relative to women in the lowest fourth, of the distribution of body weight at age 18 years was 1.5 (95% confidence interval, 1.0-2.2); at age 30, 1.9 (1.2-2.9); and 5 years before the reference date, it was 2.1 (1.4-3.3). While our results did not substantiate risk elevations reported in previous studies among subsets of women (e.g., with particular histologic tumor subtypes or according to past oral contraceptive use), we noted a particularly increased risk among women who reported 10 or more pounds gained during their first year of oral contraceptive use.

CONCLUSIONS

Our findings suggest that risk of epithelial ovarian cancer may be most closely linked with body weight in the relatively recent past (but before the time in which the disease may manifest as weight loss) among women who develop this disease during the years before or shortly after menopause.

Relation of Anthropometric Measurements to Ovarian Cancer Risk in a Population-based Case–control Study (United States)

OBJECTIVE

To examine the relationship between anthropometric measures and ovarian cancer by menopausal status.

METHODS

We analyzed data from a population-based case-control study comprised of 700 incident cases of epithelial ovarian cancer and 5,943 population controls from Massachusetts and Wisconsin enrolled between 1993 and 2001. In a telephone interview, information was gathered on established ovarian cancer risk factors, as well as adult height and age-specific body weight. Logistic regression was used to estimate multivariate-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for body mass index (BMI) throughout life.

RESULTS

Recent BMI had no significant association with ovarian cancer risk (P-trend 0.14 for continuous BMI), after adjustment for age and other ovarian cancer risk factors. However, a non-significant positive association (overall P-trend 0.08) was observed for BMI at age 20; the risk estimate comparing a body mass of >25 kg/m2 to the lowest quintile (<or=18.88 kg/m2) was moderately but non-significantly elevated (OR 1.46; 95% CI 0.92, 2.31).

CONCLUSION

Results of this study suggest that maintenance of a lean body mass, particularly in early adult life, may decrease ovarian cancer risk.

Prevention of ovarian cancer

Ovarian cancer is the leading cause of death from gynaecological malignancy. The incidence is high in the Western world. The incidence of ovarian cancer is reduced by pregnancy, lactation, the oral contraceptive pill and tubal ligation. Lifestyle factors are important in the aetiology of ovarian cancer and current evidence suggests the risk can be reduced by eating a diet rich in fruit and vegetables, taking regular exercise, avoiding smoking, avoiding being overweight and avoiding long-term use of hormonal replacement therapy (HRT). Familial ovarian cancer is responsible for about 10% of ovarian cancer cases. Strategies available to high-risk women include screening (covered elsewhere) and prophylactic salpingo-oophorectomy. The precise role of chemoprevention for high-risk women in the form of the oral contraceptive pill is unclear.

Height, age at menarche, and risk of epithelial ovarian cancer

OBJECTIVE

We hypothesized that the hormonal changes of adolescence influence ovarian cancer risk particularly in younger women. We investigated this possibility by examining the relationship between ovarian cancer and adult height and age at menarche as both factors reflect pubertal hormonal levels.

METHODS

Participants were a population-based sample of women with incident ovarian cancer (n=794) and control women randomly selected from the Australian Electoral Roll (n=855). The women provided comprehensive reproductive and lifestyle data during a standard interview.

RESULTS

Although neither height nor age at menarche was significantly related to the risk of ovarian cancer overall, increasing height was associated with increasing risk of the subgroup of mucinous borderline ovarian cancer (odds ratio, 5.3; 95% confidence interval, 1.5-19.1 for women>or=175 cm compared with women <160 cm, Ptrend=0.02). Similarly, later age at menarche was associated with increasing risk of mucinous borderline cancers (odds ratio, 3.8; 95% confidence interval, 1.3-11.4 for those with age at menarche>or=14 years compared with those <12 years, Ptrend=0.003). Women with mucinous borderline cancers were significantly younger than the women diagnosed with invasive cancers (mean 44 versus 57 years; P<0.0001).

CONCLUSIONS

Development of mucinous borderline ovarian cancers, predominantly diagnosed in women ages under 50 years, seems to be associated with age at menarche and attained adult height. These results are consistent with our original hypothesis that pubertal levels of reproductive hormones and insulin-like growth factor-I influence ovarian cancer risk in younger women.

Anthropometric Measurements and Epithelial Ovarian Cancer Risk in African–American and White women

Previous studies of anthropometric factors and ovarian cancer risk have been inconsistent and none have evaluated the association among African-American women. Data from a population-based, case-control study of 593 cases and 628 controls were used to evaluate ovarian cancer risk in relation to weight, height, body mass index (BMI) and waist-to-hip ratio (WHR). Odds ratios (ORs) and 95% confidence intervals (CIs) were computed and established risk factors were adjusted for using logistic regression models, stratified by race. Among all races, weight at age 18, WHR, weight and BMI one year prior to interview were associated with elevated ovarian cancer risk. When stratified by race, the association between WHR and ovarian was similar among Whites and among African Americans. However, African-American women in the fourth quartile of height had an elevated risk of ovarian cancer (OR = 3.2; 95% CI = 1.3-7.8), but this risk was not apparent in Whites (OR = 1.0; 95% CI = 0.7-1.4). These findings support the hypothesis that obesity is an important risk factor of ovarian cancer among African-Americans and Whites and also suggest that height may be a risk factor specific to African-Americans.

Body weight and body mass index and ovarian cancer risk: A case-control study in China

OBJECTIVE

To investigate the association between ovarian cancer risk and body height, weight, and BMI.

METHODS

A hospital-based case-control study was conducted in China from 1999 to 2000. The study sample included 254 cases with histologically confirmed epithelial ovarian cancer and 652 controls. Information of adult height and weight at diagnosis, at 5 years before diagnosis and at age 21 years, was collected by face-to-face interview using a structured questionnaire. Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained using unconditional logistic regression analyses.

RESULTS

The ovarian cancer risk was significantly increased with higher body weight and BMI at 5 years before diagnosis, but not at diagnosis nor at age 21 years. The adjusted ORs were 1.67 (95% CI = 1.04-2.67) for body weight >60 kg versus < or =50 kg and 1.75 (95% CI = 1.13-2.72) for BMI > or = 25.0 versus 18.5-21.9 at 5 years before diagnosis. There was no association between body height and ovarian cancer risk.

CONCLUSION

Pre-morbid body weight and BMI were associated with an increased risk of ovarian cancer in Chinese women.

Polycystic ovary syndrome and gynecological cancers: is there a link?

Polycystic ovary syndrome [PCOS] is the most common endocrinopathy of women in reproductive age. An association between PCOS and type-1 endometrial cancer has often been reported in the literature. The prolonged anovulation with consequent continued secretion of estrogen unopposed by progesterone may enhance the development and growth of this malignancy, particularly in young women. Hypersecretion of luteinizing hormone [LH], chronic hyperinsulinemia and increased serum insulin-like growth factor [IGF]-I levels may represent risk factors for endometrial cancer. However, data available in the literature do not allow a meta-analysis to be carried out to calculate an estimate of the relative risk of endometrial cancer in women with PCOS. Anecdotal cases of low-grade endometrial stromal sarcoma and carcinosarcoma have been reported in association with prolonged unopposed estrogen stimulation, and in particular with PCOS. A few studies have addressed the possibility of an association between PCOS and epithelial ovarian cancer risk, and the results are conflicting but generally reassuring, and similarly the few available data appear to exclude a strong association between PCOS and breast cancer.

Unanticipated findings at bariatric surgery

BACKGROUND

Obesity is associated with an increased prevalence of various intra-abdominal malignancies. There is little consensus as to the screening of the morbidly obese for these malignancies, and there are no guidelines for screening these subjects before bariatric surgery or performing a survey examination during abdominal bariatric surgery.

METHODS

A prospective analysis of 400 consecutive patients (362 women and 38 men) undergoing gastric bypass surgery was performed to identify the incidence of unanticipated intra-abdominal pathology.

RESULTS

All patients underwent abdominal exploration via an upper midline abdominal incision before gastric bypass surgery. Of the 400 patients, abnormalities were found in 31 (8%); 25 of these abnormalities were related to the ovaries. In only three cases (one case each of carcinoid of the appendix, Sertoli-Leydig cell tumor of the ovary, and serous cystadenocarcinoma of the ovary) would there have been a significant difference in the patient's prognosis had the problem been left undiagnosed.

CONCLUSION

It is reasonable to at least evaluate the ovaries in all female patients before proceeding with weight-loss surgery.

Endogenous Hormones and Ovarian Cancer: Epidemiology and Current Hypotheses

The effect of major epidemiologic risk factors for ovarian cancer has been reviewed in the light of several hormonal hypotheses, including the gonadotropin, androgens, progesterone, estrogens, insulin-like growth factor-I, and insulin hypotheses. The role of inclusion cyst formation and Mullerian epithelium differentiation in the pathology of the disease are also briefly outlined. Although based on limited data, the observed tendency in current evidence suggests possible etiologic roles for elevated androgens and estrogens and decreased progesterone in the pathogenesis of ovarian cancer. A direct effect of gonadotropins cannot be entirely ruled out, but it is plausible that their effect on ovarian cancer risk is mediated by stimulation of ovarian steroidogenesis. Insulin-like growth factor-I also emerges as a hormone that may be directly involved in the pathogenesis of the disease, but thus far only one prospective study has examined this association. Hyperinsulinemia is an unlikely risk factor for ovarian cancer. The observed tendency for an increased risk with androgens from ovarian origin (in premenopausal women), the lack of association with adrenal androgens, and the relatively weak associations observed with obesity, hormonal replacement therapy use, and endogenous hormones after menopause suggest that ovarian synthesis of sex steroids rather than their circulating levels may be etiologically important. More data from prospective studies will be crucial to improve our understanding of the etiologic role of endogenous hormones in the pathogenesis of ovarian cancer. Such data will ultimately provide opportunities for research targeted; at early detection and preventive interventions.

Common risk factors of breast and ovarian cancer: recent view

Clinicians, epidemiologists, and public health specialists tend to examine breast and ovarian cancer separately. Although this seems fairly rational and expected, both malignancies are estrogen related and thus share many risk factors. In this review, we investigate the common familial, reproductive, anthropometric, nutritional, and lifestyle risk factors of breast and ovarian cancer. We believe that the parallel examination of the two cancer types could significantly contribute to an improved prevention of "gynecological cancer" as a whole.

Dietary Determinants of Epithelial Ovarian Cancer: A Review of the Epidemiologic Literature

Ovarian cancer is commonly a fatal disease and, despite advances in screening and treatment, the lack of understanding of the underlying etiology has limited prevention strategies. This article reviews the epidemiologic literature on the relationship between consumption of major food groups and the risk of epithelial ovarian cancer (EOC). We identified 7 cohort studies and 27 case-control studies of consumption of major food groups (fruits and vegetables, meats, eggs, fish, dairy products, grains, fats and oils) and EOC risk. Vegetable but not fruit consumption was found to possibly exhibit beneficial effects on the risk of EOC, whereas high meat consumption may be associated with an increased risk. A protective effect on risk of EOC for whole-grain food consumption as well as for consumption of low-fat milk is suggested by the results of the studies. However, evidence for associations of foods such as fish, grains, milk products, and fats and oils with EOC risk is limited and inconsistent, and further examination of these dietary determinants of EOC are warranted. In conclusion, a typical Western diet, which is high in meats and low in vegetables, may be positively associated with ovarian cancer incidence. However, the association between specific dietary factors and EOC risk remains unclear and merits further examination. In particular, future studies need to address the effect of milk products according to fat content and possible biological mechanisms to explain observed effects.

Epithelial ovarian cancer risk by invasiveness and cell type in the Central Valley of California

OBJECTIVE

To evaluate epithelial ovarian cancer (EOC) risk factors by level of invasiveness and histology.

METHODS

A population-based epidemiologic case-control study of EOC was conducted over a 2-year period (January 2000 to December 2001) in 22 counties of Central California that comprise the reporting area for two regional cancer registries. Telephone interviews were conducted with 256 cases and 1122 control frequencies matched on age and ethnicity. The interview obtained information on demographic factors as well as information pertinent to the respondent's menstrual and reproductive experience, use of exogenous hormones, surgical history, and family history of cancer. Adjusted odds ratios were calculated using stratification as well as Logistic regression methods. Analyses were completed by level of invasiveness and cell type.

RESULTS

Strong protective associations were observed for use of oral contraceptives and parity. Risk increased with a family history of ovarian, but not breast cancer and age at first birth was positively associated with increased risk. Hormone replacement therapy was associated with increased risk only in long-term users. Many of the relationships were observed only in specific histologic subtypes of EOC.

CONCLUSION

Risk of EOC is associated with several lifestyle and environmental exposures but the impact of these effects appears to be dependent upon level of invasiveness and histologic subtypes of EOC. However, the sample size available for analysis limits our statistical power and our ability to analyze data by histologic subtype, thus limiting interpretation of our results.

Prevention of cancers of the breast, endometrium and ovary

A central epidemiological feature of cancers of the breast, endometrium and ovary is the sharp slowing down in their rate of increase with age around the time of menopause. The incidence of these tumors by the age of 70 years would be between fourfold and eightfold increased if the rapid increase with age seen in young women continued into old age. These phenomena can be explained by the different effects of ovarian hormones on cell division rates in the relevant tissues. Models of these effects provide a plausible explanation of most of the known epidemiology of each of the cancers, including the increase in breast cancer risk from menopausal estrogen-progestin therapy. Some recent epidemiological findings in endometrial and ovarian cancer suggest new avenues for possible chemoprevention of these cancers.

Synchronous primary cancers of the endometrium and ovary: a single institution review of 84 cases

OBJECTIVES

Synchronous primary cancers of the endometrium and ovary are found in 10% of women with ovarian cancer and 5% of women with endometrial cancer. The purpose of this study was to characterize patients diagnosed with synchronous primary cancers of the endometrium and ovary with an emphasis on risk factors.

METHODS

Between 1989 and 2002, 84 patients with synchronous primary cancers of the endometrium and ovary were identified. Patients with uterine papillary serous carcinoma were excluded. Clinical and pathologic information was obtained from medical records. Parametric methods were used to compare clinical and pathologic features. Kaplan-Meier survival analyses were performed and compared using the log rank test.

RESULTS

Median age at diagnosis was 50 years. Median body mass index (BMI) was 28 kg/m(2). Fifty-one percent (43/84) of the women were premenopausal and 33% (28/84) were nulliparous. The most common presenting symptom was abnormal vaginal bleeding; in those women with abnormal vaginal bleeding, 69% had stage I ovarian cancer. Ovarian cancer was an incidental finding in 48% of these patients. Sixty-eight percent of patients (57/84) had endometrioid histology of both their endometrial and ovarian cancers. Patients with early stage ovarian cancer tended to have a more favorable prognosis than those with advanced stage disease (median survival not reached in stage I and II versus 66 months in stage III and IV, P = 0.06). Patients with concordant endometrioid histology had a favorable prognosis (median survival 119 versus 48 months in all other groups, P = 0.02).

CONCLUSIONS

In this large series of patients, women with synchronous primary cancers of the endometrium and ovary were young, obese, nulliparous, and premenopausal. Patients with concordant endometrioid tumors of the endometrium and ovary had a favorable prognosis, with median survival approaching 10 years.

Hormonal factors and the risk of invasive ovarian cancer: a population-based case-control study

OBJECTIVE

To examine the influence of hormone-related factors on the risk of invasive epithelial ovarian cancer (ovarian cancer).

DESIGN

Population-based case-control study using in-person interviews.

SETTING

Academic department of preventive medicine.

PATIENT(S)

Four hundred seventy-seven ovarian cancer patients and 660 controls.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Numbers of and ages at births, oral contraceptive use, and use of menopausal hormone therapy.

RESULT(S)

Compared with nulliparous women, women whose only (last) birth was after age 35 years had an estimated 51% (95% confidence interval: 21%-70%) reduction in risk. If this birth occurred earlier, the reduction in risk was progressively less. Additional (earlier) births reduced the risk further. Oral contraceptive use also reduced risk. Increased body mass index increased risk, but this effect was confined to localized disease and is likely to be a diagnostic bias, as a consequence of other problems associated with being overweight and in itself having no etiological significance.

CONCLUSION(S)

If the major protective effect of a late birth can be confirmed, our most challenging task will be to understand the mechanism to develop a chemoprevention approach to exploit this finding.

Anthropometric variables, physical activity, and incidence of ovarian cancer

BACKGROUND

Reports on the relation between anthropometric variables (height, weight) and physical activity with ovarian cancer have been inconclusive. The objective of the current study was to extend investigation of potential associations in the Iowa Women's Health Study cohort.

METHODS

The relation between self-reported anthropometric variables and incident ovarian cancer was studied in a prospective cohort of women ages 55-69 years who were followed for 15 years. Two hundred twenty-three incident cases of epithelial ovarian cancer were identified by linkage to a cancer registry.

RESULTS

No association was found overall between ovarian cancer and height, but a positive association was observed for serous ovarian cancers (relative risk [RR], 1.86 for highest quartile vs. lowest quartile; 95% confidence interval [95% CI], 1.06-3.29). Although current body mass index (BMI) was not associated with ovarian cancer, a BMI > or =30 kg/m2 at age 18 years appeared to be associated positively with ovarian cancer (multivariate-adjusted RR, 1.83 for BMI > or =30 kg/m2 vs. BMI <25 kg/m2; 95% CI, 0.90-3.72), and this association was stronger after exclusion of the first 2 years of follow-up (RR, 2.15; 95% CI, 1.05-4.40). In a multivariate analysis, waist-to-hip ratio was associated with ovarian cancer (RR, 1.59 for highest quartile vs. lowest quartile; 95% CI, 1.05-2.40), but a linear dose response was not found. An index that combined the frequency and intensity of leisure-time physical activity was associated positively with ovarian cancer incidence (multivariate-adjusted RR, 1.42 for high activity vs. low activity; 95% CI, 1.03-1.97). This association was particularly strong for frequency of vigorous physical activity (multivariate-adjusted RR, 2.38 for >4 times per week vs. rarely/never; 95% CI, 1.29-4.38).

CONCLUSIONS

Anthropometric variables were not major risk factors for ovarian cancer in the cohort studied; however, high BMI in early adulthood and frequent and vigorous physical activity may increase the risk of ovarian cancer among postmenopausal women.

Circulating soluble Fas levels and risk of ovarian cancer

BACKGROUND

Dysregulation of apoptosis, specifically overexpression of soluble Fas (sFas), has been proposed to play a role in the development of ovarian cancer. The main objective of the present study was to evaluate serum sFas as a potential biomarker of ovarian cancer risk.

METHODS

The association between serum sFas levels and the risk of ovarian cancer was examined in a case-control study nested within three prospective cohorts in New York (USA), Umeå (Sweden), and Milan (Italy). Case subjects were 138 women with primary invasive epithelial ovarian cancer diagnosed between 2 months and 13.2 years after the initial blood donation. Control subjects were 263 women who were free of cancer, and matched the case on cohort, menopausal status, age, and enrollment date. Serum sFas levels were determined using a quantitative sandwich enzyme immunoassay.

RESULTS

Serum sFas levels were similar in women subsequently diagnosed with ovarian cancer (median, 6.5 ng/mL; range, 4.4-10.2) and in controls (median, 6.8 ng/mL; range, 4.5-10.1). Statistically significant trends of increasing serum sFas with age were observed among cases (r = 0.39, p < 0.0001) and controls (r = 0.42, p < 0.0001). Compared to women in the lowest third, women in the highest third of serum sFas were not at increased risk of ovarian cancer after adjustment for potential confounders (odd ratio (OR), 0.87; 95% confidence interval (CI), 0.42-1.82).

CONCLUSION

The results suggest that serum sFas may not be a suitable marker for identification of women at increased risk of ovarian cancer.

Height, body mass index, and ovarian cancer: a follow-up of 1.1 million Norwegian women

Body mass index (BMI) has shown both positive and negative associations with ovarian cancer. Whether a possible association between height and ovarian cancer exists is unknown. We explored whether BMI and height were associated with ovarian cancer risk in a Norwegian cohort of approximately 1.1 million women, aged 14-74 years who were measured between 1963 and 1999. The cohort was followed for an average of 25 years through linkage to population-based cancer and death registries. Among the cohort, 7882 histologically verified cases of ovarian cancer were registered. Relative to women with a medium BMI (18.5-24.9 kg/m2), women who were overweight or obese in adolescence or young adulthood had an increased risk of ovarian cancer; women with a very high BMI in adolescence had a relative risk of 1.56 (95% confidence interval = 1.04 to 2.32) compared with women with medium BMI. No such association was seen in older women. A positive association between height and risk of ovarian cancer, particularly endometrioid ovarian cancer, was observed in women younger than 60 years of age.

Endometriosis and ovarian cancer: thoughts on shared pathophysiology

BACKGROUND

Endometriosis appears to predispose to ovarian cancer. How this may occur has been little discussed.

STUDY DESIGN

This article reviews the English language literature for in vitro, animal, clinical, and epidemiologic studies linking the two conditions.

RESULTS

Pathology case series consistently report endometrioid and clear cell types of ovarian cancer arising from endometriotic foci. Epidemiologic studies have been consistent with this association. There are also marked similarities between the proposed etiology of ovarian cancer and the observed pathophysiology of endometriosis. Specifically, both are characterized by immune alterations. Both conditions are promoted by estrogen excess and by progesterone deficit. Finally, steroid hormones interacting with the immune system may stimulate both endometriosis and ovarian cancer. I propose that the biology common to endometriosis and ovarian cancer represents not just a parallelism, but instead a causal pathway: aberrant immune function, fed by and feeding on estrogens, unbalanced by progesterone, may create a positive feed-forward loop that enhances the growth and invasiveness of endometriosis and promotes its malignant transformation.

CONCLUSIONS

The same pathophysiology may orchestrate the progression of endometriosis and its transformation to endometroid and clear cell ovarian neoplasias. This notion of a unifying biology suggests a directed approach to future research and identifies possible chemoprevention strategies for women with endometriosis.

Reliability of follicle-stimulating hormone measurements in serum

BACKGROUND

Follicle-stimulating hormone (FSH), a member of gonadotropin family, is critical for follicular maturation and ovarian steroidogenesis. Serum FSH levels are known to fluctuate during different phases of menstrual cycle in premenopausal women, and increase considerably after the menopause as a result of ovarian function cessation. There is little existing evidence to guide researchers in estimating the reliability of serum FSH measurements. The objective of this study was to assess the reliability of FSH measurement using stored sera from an ongoing prospective cohort--the NYU Women's Health Study.

METHODS

Sixty healthy women (16 premenopausal, 44 postmenopausal), who donated at least two blood samples at approximately 1-year intervals were studied. An immunoradiometric assay using a sandwich monoclonal antibodies technique was used to measure FSH levels in serum.

RESULTS

The reliability of a single log-transformed FSH measurement, as determined by the intraclass correlation coefficient, was 0.70 for postmenopausal women (95% confidence interval (CI), 0.55-0.82) and 0.09 for premenopausal women (95% CI, 0-0.54).

CONCLUSIONS

These results suggest that a single measurement is sufficient to characterize the serum FSH level in postmenopausal women and could be a useful tool in epidemiological research. For premenopausal women, however, the reliability coefficient was low, suggesting that a single determination is insufficient to reliably estimate a woman's true average serum FSH level and repeated measurements are desirable.

A comprehensive look at the early detection of ovarian cancer

Ovarian cancer is the leading cause of gynecologic cancer deaths and the fifth leading cause of cancer deaths among American women. Advances in surgery and treatment modalities have slightly improved five-year survival rates, but the prognosis for most women continues to be poor. Rectovaginal examination, ultrasound, and the CA-125 blood test are three modalities currently used to screen for ovarian cancer, although no universal ovarian cancer screening guidelines are recommended for the general population. Developments in the early detection of ovarian cancer are emerging and include blood tests that could lead to identifying asymptomatic, early-stage ovarian cancer. Nurses should be knowledgeable about these developments in ovarian cancer as they educate women about ovarian cancer risk, prevention, and early detection.

Trends in incidence rates for obesity-associated cancers in the US

The purpose of this study was to assess the possible impact of rising prevalence of obesity in US adults (since the late 1970s) on incidence rates (1973-1999) for cancers strongly associated with obesity, and to estimate the number of incident cancers (in 2002) potentially attributable to obesity. Data from a group of high-quality population-based cancer registries, regarded as generally representative of the unknown cancer rates in the entire US, were used to obtain average annual age-standardized incidence rates (ASIRs) per 100,000 from 1973 to 1975 through 1997-1999 for selected obesity-related cancers. Temporal increases in ASIRs were evident during the entire period for kidney and adenocarcinomas of the esophagus and gastric cardia, while during the 1990's the decline in ASIRs for adenocarcinoma of the uterine corpus was reversed and the ASIRs for breast cancer continued to increase for age 50+ years, suggesting a potential impact of rising obesity prevalence rates. An estimated 41,383 new cancers (about 3.2% of all cancers) diagnosed in the US in 2002 may be potentially attributable to obesity. Further analytic epidemiologic studies are needed to assess the risks of other cancers in relation to both obesity and body fat distribution.