Height and cancer incidence in the Million Women Study: prospective cohort, and meta-analysis of prospective studies of height and total cancer risk

Exposures in early life: associations with DNA promoter methylation in breast tumors

There is evidence that epigenetic changes occur early in breast carcinogenesis. We hypothesized that early-life exposures associated with breast cancer would be associated with epigenetic alterations in breast tumors. In particular, we examined DNA methylation patterns in breast tumors in association with several early-life exposures in a population-based case-control study. Promoter methylation of E-cadherin, p16 and RAR-β2 genes was assessed in archived tumor blocks from 803 cases with real-time methylation-specific PCR. Unconditional logistic regression was used for case-case comparisons of those with and without promoter methylation. We found no differences in the prevalence of DNA methylation of the individual genes by age at menarche, age at first live birth and weight at age 20. In case-case comparisons of premenopausal breast cancer, lower birth weight was associated with increased likelihood of E-cadherin promoter methylation (OR = 2.79, 95% CI, 1.15-6.82, for ⩽2.5 v. 2.6-2.9 kg); higher adult height with RAR-β2 methylation (OR = 3.34, 95% CI, 1.19-9.39, for ⩾1.65 v. <1.60 m); and not having been breastfed with p16 methylation (OR = 2.75, 95% CI, 1.14-6.62). Among postmenopausal breast cancers, birth order was associated with increased likelihood of p16 promoter methylation. Being other than first in the birth order was inversely associated with likelihood of ⩾1 of the three genes being methylated for premenopausal breast cancers, but positively associated with methylation in postmenopausal women. These results suggest that there may be alterations in methylation associated with early-life exposures that persist into adulthood and affect breast cancer risk.

Cancer and body height

OBJECTIVE

To test the hypothesis that body-resonant radiation may explain the correlation between body height and cancer risk observed in most countries around the world.

METHODS

Data on cancer incidence and body height were collected from different countries and also from different regions within Sweden. Information on local FM broadcasting transmitters was also collected in Sweden to determine whether they correlated with the cancer incidence and body heights reported in each geographical area. Because broadcasting radiation may be concentrated by metal spring mattresses, we also attempted to collect information on the use of these mattresses in different parts of the world.

RESULTS

A strong association was found between melanoma incidence and body height, both in different countries and in different municipalities within Sweden. At the same time, a very strong association was found between cancer incidence, mean body height, and the effective number of FM transmitters covering a given locality. Available data on the use of metal spring mattresses in different parts of the world also correlated well with data on cancer rates and body heights.

CONCLUSIONS

The hypothesis that body-resonant radiation may affect both cancer incidence and body height was supported by the strong associations found in this study. The hypothesis was further supported by the correlation found between the incidence of cancer, body height, and the use of metal spring mattresses.

Growth hormone is secreted by normal breast epithelium upon progesterone stimulation and increases proliferation of stem/progenitor cells

Using in vitro and in vivo experimental systems and in situ analysis, we show that growth hormone (GH) is secreted locally by normal human mammary epithelial cells upon progesterone stimulation. GH increases proliferation of a subset of cells that express growth hormone receptor (GHR) and have functional properties of stem and early progenitor cells. In 72% of ductal carcinoma in situ lesions, an expansion of the cell population that expresses GHR was observed, suggesting that GH signaling may contribute to breast cancer development.

Predictors for thyroid carcinoma in Israel: a national cohort of 1,624,310 adolescents followed for up to 40 years

INTRODUCTION

Data on adolescent precursors of thyroid cancer in adulthood are scant.

METHODS

In order to evaluate potential risk factors for thyroid cancer, we linked two national data sources: the military recruitment health examinations and the Israel National Cancer Register. The study population (1,624,310 participants) included 1,145,865 Jewish males aged 16-19 years when examined between 1967 and 2005, and 478,445 Jewish females aged 16-19 years when examined between 1989 and 2005. The cancer follow-up extended up to 2006. Multivariable Cox proportional hazards modeling was used.

RESULTS

During 24,389,502 person years of follow-up, 760 incidence cases of thyroid cancer were identified. The mean age at diagnosis was 25.2±4.2 years for women and 37.2±10.0 years for men. Women had a substantially higher incidence (birth cohort-adjusted hazard ratio (HR)=5.70 [95% CI 4.45-7.31]; p<0.001). Height predicted incidence in both sexes, with birth cohort-adjusted HRs of 1.03 (p<0.001) in males and 1.04 (p<0.001) in females, per 1 cm increment in height. In males, but not in females, there was a graded association between education, as measured by years of schooling, and incidence of thyroid cancer. Body mass index was not associated with incidence. In a multivariable analysis of 617,613 males and 469,185 females examined from 1989 onwards, which included sex, birth year, height, and education, the excess risk in females persisted strongly (HR=5.67 [CI 4.30-7.13]), as did the association with height.

CONCLUSIONS

Female sex, measured height in adolescence, and later birth cohorts were independent predictors of thyroid cancer in young and middle-aged adults in Israel. Further study is needed to unravel the mechanisms whereby height is associated with thyroid cancer.

Insulin-like growth factor-i and risk of differentiated thyroid carcinoma in the European prospective investigation into cancer and nutrition

BACKGROUND

Little is known about the causes of thyroid cancer, but insulin-like growth factor-I (IGF-I) might play an important role in its development due to its mitogenic and antiapoptotic properties.

METHODS

This study prospectively investigated the association between serum IGF-I concentrations and risk of differentiated thyroid carcinoma in a case-control study nested within the European Prospective Investigation into Cancer and Nutrition. The 345 incident cases of differentiated thyroid carcinoma were individually matched to 735 controls by study center, sex and age, date, time, and fasting status at blood collection, follow-up duration, and for women menopausal status, use of exogenous hormones, and phase of menstrual cycle at blood collection. Serum IGF-I concentrations were measured by immunoassay, and risk of differentiated thyroid cancer in relation to IGF-I concentration was estimated using conditional logistic regression.

RESULTS

There was a positive association between IGF-I concentrations and risk of differentiated thyroid carcinoma: the OR for a doubling in IGF-I concentration was 1.48 (95% confidence interval, 1.06-2.08; Ptrend = 0.02). The positive association with IGF-I was stable over time between blood collection and cancer diagnosis.

CONCLUSION

These findings suggest that IGF-I concentrations may be positively associated with risk of differentiated thyroid carcinoma.

IMPACT

This study provides the first prospective evidence of a potential association between circulating IGF-I concentrations and risk of differentiated thyroid carcinoma and may prompt the further investigations needed to confirm the association.

Cancer risk from low dose radiation depends directly on the organ mass in a general model of radiation-induced cancer risk

Current methods of evaluating radiation-induced cancer risk depend on the organ dose but not explicitly on extensive quantities such as the organ mass. However, at the same organ dose, one may expect the larger number of cells in a larger organ to lead to a higher cancer risk. Here the author introduces organ- and radiation type-specific cell cancer risk coefficients and obtains analytical relations between cancer risk and the radiation environment, which contains the dependence of cancer risk on organ masses. The excess cancer risk induced by low dose radiation for an organ is shown to be directly proportional to the organ mass. Therefore the total excess risk for all solid cancers depends directly on organ masses and consequently on body weight or size. This method is also being compared with three existing methods of evaluating the radiation-induced cancer risk, and special cases where this formulation matches each method are demonstrated. The results suggest that the direct dependence of cancer risk on organ masses needs to be checked against existing epidemiological data and, if verified, should be included in the methodology for the evaluation of radiation-induced cancer risk, in particular the individual risk. This dependence is also expected to affect the cancer risk transport from one population group to another that is different in organ mass, body weight or height.

Prognostic significance and predictors of the neutrophil-to-lymphocyte ratio in ovarian cancer

OBJECTIVE

To investigate the neutrophil-to-lymphocyte ratio (NLR) from peripheral blood, a general measure of inflammation, in ovarian cancer.

METHODS

White cell counts and CA125 levels before treatment, tumor features, and questionnaire data on 519 women with ovarian cancer at two Boston hospitals were recorded. Counts were log-transformed and effects on these by tumor features and epidemiologic variables assessed by analysis of variance and generalized linear models. Cox proportional hazards models were used to assess effects on overall survival.

RESULTS

Greater NLR was associated with higher tumor stage and grade, presence of ascites, and bilateral disease and correlated with risk factors including Jewish ethnicity, taller height, more ovulatory cycles, and family history of cancer in premenopausal women and talc use in all women. CA125 was positively correlated with neutrophil count, monocyte count, and NLR and inversely correlated with lymphocyte count. In a multivariate adjusted analysis, high NLR predicted poorer survival and high lymphocyte count better survival.

CONCLUSION

An elevated NLR before treatment signals more aggressive disease and correlates with risk factors for ovarian cancer. CA125 directly correlates with neutrophils which may reflect secretion of both CA125 and neutrophilic growth factors by the tumor. CA125 inversely correlates with lymphocytes which may reflect the ability of some neutrophilic factors to induce lymphopenia and/or binding of CA125 to lymphocytes removing CA125 from the serum pool. Links between NLR, CA125, and epidemiologic factors may provide new clues about the pathogenesis and progression of ovarian cancer.

Ethnic differences in breast cancer incidence in England are due to differences in known risk factors for the disease: prospective study

BACKGROUND

In the United Kingdom, breast cancer incidence is lower in South Asian and Black women than in White women, but the extent to which this is due to known risk factors is unknown. In a large prospective study, we describe breast cancer incidence by ethnicity, before and after adjustment for known risk factors for the disease.

METHODS

Women were recruited into the Million Women Study in 1996-2001, when information on reproductive and lifestyle factors known to influence the risk of breast cancer was obtained. Ethnicity was determined from study questionnaires and hospital admission data. Cox regression models were used to calculate adjusted relative risks (RR) for incident breast cancer in South Asians and Blacks compared with Whites.

RESULTS

Analyses included 5877 South Asian, 4919 Black, and 1,038,144 White women in England. The prevalence of 8 out of the 9 risk factors for breast cancer examined, differed substantially by ethnicity (P<0.001 for each), such that South Asian and Black women were at a lower risk of the disease than White women. During 12.2 years of follow-up incident breast cancer occurred in 217 South Asians, 180 Blacks, and 45,191 Whites. As expected, breast cancer incidence was lower in South Asians (RR=0.82, 95% CI 0.72-0.94) and Blacks (RR=0.85, 0.73-0.98) than in Whites when the analyses were adjusted only for age and region of residence. However, after additional adjustment for the known risk factors for the disease, breast cancer incidence was similar to that of Whites, both in South Asians (0.95, 0.83-1.09) and in Blacks (0.91, 0.78-1.05).

CONCLUSION

South Asian and Black women in England have lower incidence rates of breast cancer than White women, but this is largely, if not wholly, because of differences in known risk factors for the disease.

Adult height and head and neck cancer: a pooled analysis within the INHANCE Consortium

Several epidemiological studies have shown a positive association between adult height and cancer incidence. The only study conducted among women on mouth and pharynx cancer risk, however, reported an inverse association. This study aims to investigate the association between height and the risk of head and neck cancer (HNC) within a large international consortium of HNC. We analyzed pooled individual-level data from 24 case-control studies participating in the International Head and Neck Cancer Epidemiology Consortium. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated separately for men and women for associations between height and HNC risk. Educational level, tobacco smoking, and alcohol consumption were included in all regression models. Stratified analyses by HNC subsites were performed. This project included 17,666 cases and 28,198 controls. We found an inverse association between height and HNC (adjusted OR per 10 cm height = 0.91, 95% CI 0.86-0.95 for men; adjusted OR = 0.86, 95% CI 0.79-0.93 for women). In men, the estimated OR did vary by educational level, smoking status, geographic area, and control source. No differences by subsites were detected. Adult height is inversely associated with HNC risk. As height can be considered a marker of childhood illness and low energy intake, the inverse association is consistent with prior studies showing that HNC occur more frequently among deprived individuals. Further studies designed to elucidate the mechanism of such association would be warranted.

Height, weight, and body mass index associations with gastric cancer subsites

BACKGROUND

Although excess body weight has been associated with cancers of the gastric cardia, relationships with gastric cancer at other anatomic subsites are not well defined. Furthermore, subsite-specific associations with attained height have not been fully assessed.

METHODS

In 1995-1996, 483,700 Whites enrolling in the multi-state NIH-AARP Diet and Health Study self-reported height and weight. Gastric cancers occurring through 31 December 2006 were ascertained from regional population-based registries. We used Cox regression models to estimate cancer hazard ratios (HRs) for sex-specific tertiles of height and weight and for body mass index (BMI) categories of the World Health Organization.

RESULTS

One thousand incident cancers (48 % localized to the cardia, 4 % fundus, 6 % corpus, 3 % greater curvature, 6 % lesser curvature, 10 % antrum, 2 % pylorus, 5 % overlapping lesion, and 16 % unspecified) occurred an average of 5.4 years after enrollment. After controlling for effects of age, sex, education, and smoking, we found an inverse association between height and total noncardia cancers (i.e., fundus, corpus, greater and lesser curvatures, antrum, and pylorus), with HRs vs. tertile 1 of 0.65 and 0.71 for tertiles 2 and 3, respectively (p trend = 0.016). Trends were consistent for individual noncardia subsites. In contrast, although weight and BMI were each associated with risk of cardia cancer, neither was associated with total noncardia cancer nor individual subsites.

CONCLUSION

Noncardia gastric cancer is associated with short stature but not with high body weight or obesity. The excess risk for shorter adults would be consistent with the known association of chronic H. pylori infection with growth retardation during childhood.

Pooled cohort study on height and risk of cancer and cancer death

PURPOSE

To assess the association between height and risk of cancer and cancer death.

METHODS

The metabolic syndrome and cancer project is a prospective pooled cohort study of 585,928 participants from seven cohorts in Austria, Norway, and Sweden. Hazard ratios (HRs) and 95 % confidence intervals (CIs) for cancer incidence and death were estimated in height categories and per 5-cm increment for each cancer site using Cox proportional hazards model.

RESULTS

During a mean follow-up of 12.7 years (SD = 7.2), 38,862 participants were diagnosed with cancer and 13,547 participants died of cancer. Increased height (per 5-cm increment) was associated with an increased overall cancer risk in women, HR 1.07 (95 % CI 1.06-1.09), and in men, HR 1.04 (95 % CI 1.03-1.06). The highest HR was seen for malignant melanoma in women, HR 1.17 (95 % CI 1.11-1.24), and in men HR 1.12 (95 % CI 1.08-1.19). Height was also associated with increased risk of cancer death in women, HR 1.03 (95 % CI 1.01-1.16), and in men, HR 1.03 (95 % CI 1.01-1.05). The highest HR was observed for breast cancer death in postmenopausal women (>60 years), HR 1.10 (95 % CI 1.00-1.21), and death from renal cell carcinoma in men, HR 1.18 (95 % CI 1.07-1.30). All these associations were independent of body mass index.

CONCLUSION

Height was associated with risk of cancer and cancer death indicating that factors related to height such as hormonal and genetic factors stimulate both cancer development and progression.

Childhood infections and adult height in monozygotic twin pairs

Adult height is determined by genetics and childhood nutrition, but childhood infections may also play a role. Monozygotic twins are genetically matched and offer an advantage when identifying environmental determinants. In 2005-2007, we examined the association of childhood infections with adult height in 140 height-discordant monozygotic twin pairs from the California Twin Program. To obtain information on childhood infections and growth, we interviewed the mothers of monozygotic twins who differed in self-reported adult height by at least 1-inch (2.5 cm). Within-pair differences in the relative frequency of childhood infections were highly correlated, especially within age groups. A conditional logistic regression analysis demonstrated that more reported episodes of febrile illness occurred in the twin with shorter stature (odds ratio = 2.00, 95% confidence interval: 1.18, 3.40). The association was strongest for differences in the relative frequency of infection during the toddler years (ages 1-5: odds ratio = 3.34, 95% confidence interval: 1.47, 7.59) and was similar when restricted to twin pairs of equal birth length. The association was not explained by differential nutritional status. Measures of childhood infection were associated with height difference in monozygotic twin pairs, independent of genome, birth length, and available measures of diet.

Growth hormone and cancer: an update on progress

PURPOSE OF REVIEW

Animals born with a deficiency in the cell surface receptor for growth hormone (GH) have a significantly reduced risk of developing cancer. Conversely, increased expression levels of GH and the GH receptor (GHR) are detectable in a variety of different human cancers. Here we discuss recent literature contributing to our understanding of the field.

RECENT FINDINGS

In addition to animal evidence, studies of individuals with Laron syndrome suggest that congenital GHR deficiency may also protect humans against cancer. GH expression in certain malignancies is correlated with clinicohistopathological parameters and may contribute the therapeutic resistance. Other recent studies have identified novel aspects of the GH signal transduction pathway, including receptor crosstalk and the involvement of microRNA in endocrine regulation of GH.

SUMMARY

Substantial evidence suggests the GH/insulin-like growth factor-1 axis initiates and promotes progression of cancer. However, important questions remain unanswered regarding the therapeutic utility of GH or GHR antagonism in cancer. Further clinical studies regarding the clinical association of GH expression with human malignancies and translational studies investigating GHR antagonism in animal models of human cancer are critical.

A prospective analysis of body size during childhood, adolescence, and adulthood and risk of non-Hodgkin lymphoma

The etiology of non-Hodgkin lymphoma (NHL) is poorly understood. Obesity is associated with inflammation, a cytokine milieu conducive to lymphocyte proliferation, and has been associated with NHL risk in some epidemiologic studies. To prospectively examine NHL risk in relation to adult and earlier life obesity, we documented 635 incident NHL diagnoses among 46,390 men in the Health Professionals Follow-up Study and 1,254 diagnoses among 116,794 women in the Nurses' Health Study over 22 to 32 years of follow-up. Using multivariable Cox proportional hazards models, we estimated cohort-specific incidence rate ratios (RR) and 95% confidence intervals (CI) for risk of NHL and major histologic subtypes associated with cumulative average middle and young adult (ages, 18-21 years) body mass index (BMI) and adolescent and childhood somatotype. NHL risk was modestly increased in men (but not women) with a cumulative average middle adult BMI ≥ 30 kg/m(2) (vs. 15-22.9 kg/m(2); RR, 1.28; 95% CI, 0.92-1.77; Ptrend = 0.05). In meta-analyses across cohorts, higher young adult BMI was associated with increased risk of all NHL (pooled RR per 5 kg/m(2), 1.19; 95% CI, 1.05-1.37), diffuse large B-cell lymphoma (DLBCL), and follicular lymphoma (all Ptrend ≤ 0.02). Adolescent somatotype was also positively associated with all NHL, DLBCL, and follicular lymphoma in pooled analyses (all Ptrend ≤ 0.03), whereas childhood somatotype was positively associated with NHL overall among women only (Ptrend < 0.01). These findings in two large prospective cohorts provide novel evidence that larger body size in childhood, adolescence, and young adulthood predicts increased risk of NHL, and particularly of DLBCL and follicular lymphoma.

Adult stature and risk of cancer at different anatomic sites in a cohort of postmenopausal women

BACKGROUND

Prospective studies in Western and Asian populations suggest that height is a risk factor for various cancers. However, few studies have explored potential confounding or effect modification of the association by other factors.

METHODS

We examined the association between height measured at enrollment in 144,701 women participating in the Women's Health Initiative and risk of all cancers combined and cancer at 19 specific sites. Over a median follow-up of 12.0 years, 20,928 incident cancers were identified. We used Cox proportional hazards models to estimate HR and 95% confidence intervals (CI) per 10 cm increase in height, with adjustment for established risk factors. We also examined potential effect modification of the association with all cancer and specific cancers.

RESULTS

Height was significantly positively associated with risk of all cancers (HR = 1.13; 95% CI, 1.11-1.16), as well as with cancers of the thyroid, rectum, kidney, endometrium, colorectum, colon, ovary, and breast, and with multiple myeloma and melanoma (range of HRs: 1.13 for breast cancer to 1.29 for multiple myeloma and thyroid cancer). These associations were generally insensitive to adjustment for confounders, and there was little evidence of effect modification.

CONCLUSIONS

This study confirms the positive association of height with risk of all cancers and a substantial number of cancer sites.

IMPACT

Identification of single-nucleotide polymorphisms associated both with height and with increased cancer risk may help elucidate the association.

Metastatic renal cell carcinoma: update on epidemiology, genetics, and therapeutic modalities

The treatment of advanced renal cell carcinoma (RCC) remains a major therapeutic challenge for clinicians. Despite advances in the understanding of the immunobiology of RCC and the availability of several novel targeted agents, there has been little improvement in the survival of patients with metastatic RCC. This review will focus on the recent understanding of risk factors and treatment options and outcomes of metastatic RCC, in particular, targeted therapeutic agents that inhibit vascular endothelial growth factor and mammalian target of rapamycin pathways. Prospective studies are required to determine whether sequential targeted therapy will further improve progression-free survival in RCC. Ongoing research to develop novel agents with better tolerability and enhanced efficacy in the treatment of metastatic RCC is required.

Childhood and adult cancers: contrasts and commonalities

Tumours occurring in children differ considerably from those occurring at older ages but exhibit common features. Those occurring in the teenage/young adult (TYA) years represent a transitional mixture of child and adult tumours and pose a considerable challenge for optimal clinical management and service provision. Nevertheless the fundamental processes of malignant change, arising from genetic/epigenetic interaction with environmental exposures, seem to operate across all ages and the entire tumour spectrum. We focus here on the ways in which genotype (and epigenetic modification), growth processes (particularly in utero), and exposure to ionising radiation (in conjunction with genetic susceptibility) affect cancer risk from childhood to adulthood, whether as a primary occurrence, or a second primary tumour following earlier primary occurrence and treatment.

Associations of mortality with own height using son's height as an instrumental variable

Height is associated with mortality from many diseases, but it remains unclear whether the association is causal or due to confounding by social factors, genetic pleiotropy,(1) or existing ill-health. The authors investigated whether the association of height with mortality is causal by using a son's height as an instrumental variable (IV) for parents' height among the parents of a cohort of 1,036,963 Swedish men born between 1951 and 1980 who had their height measured at military conscription, aged around 18, between 1969 and 2001. In a two-sample IV analysis adjusting for son's age at examination and secular trends in height, as well as parental age, and socioeconomic position, the hazard ratio (HR) for all-cause paternal mortality per standard deviation (SD, 6.49cm) of height was 0.96 (95% confidence interval (CI): 0.95, 0.96). The results of IV analyses of mortality from all causes, cardiovascular disease (CVD), respiratory disease, cancer, external causes and suicide were comparable to those obtained using son's height as a simple proxy for own height and to conventional analyses of own height in the present data and elsewhere, suggesting that such conventional analyses are not substantially confounded by existing ill-health.

Height as an explanatory factor for sex differences in human cancer

BACKGROUND

Most cancers occur more frequently in men. Numerous explanations for this excess risk have been proposed, yet no study has quantified the degree to which height explains the sex difference even though greater height has been associated with increased risk for many cancers.

METHODS

During the period from 2000 to 2002, 65308 volunteers aged 50 to 76 years were recruited to the Vitamins And Lifestyle (VITAL) study. Cancers of shared anatomic sites (n = 3466) were prospectively identified through 2009 through the Surveillance, Epidemiology, and End Results cancer registry. Age- and race-adjusted hazard ratios (HRs) for the associations between sex and incident cancers were estimated using Cox proportional hazards models, with and without adjustment for height and height squared as measures of body size.

RESULTS

Men had a 55% increased risk of cancer at shared sites (HR = 1.55; 95% confidence interval [CI] = 1.45 to 1.66). When height was accounted for, 33.8% (95% CI = 10.2% to 57.3%) of the excess risk for men was explained by the height differences between sexes. The proportion mediated by height was 90.9%, 57.3%, and 49.6% for kidney, melanoma, and hematologic malignancies, respectively, with little evidence that height mediates the sex difference for gastrointestinal tract, lung, and bladder cancers. For comparison, more than 35 lifestyle and medical risk factors only explained 23.1% of the sex difference in cancer risk at shared sites.

CONCLUSIONS

Height is an important explanatory factor for the excess risk for men for many shared-site cancers. This suggests that some of the excess risk is due to factors associated with height (eg, number of susceptible cells in a specific organ or growth-influencing exposures in childhood).

Influence of adult height on rheumatoid arthritis: association with disease activity, impairment of joint function and overall disability

Objectives

To investigate whether normal variation of adult height is associated with clinical characteristics in rheumatoid arthritis (RA), including disease activity (DAS28), impairment of joint function (mechanical joint score, MJS) and overall disability (health assessment questionnaire, HAQ).

Methods

A cohort (134 males, 287 females) of consecutively recruited RA patients of Northern European origin was studied. Height, weight and demographic information were obtained. A core set of disease measurements, including DAS28, MJS and HAQ, were recorded at baseline, 12 and 24 months. Other clinical variables (e.g. disease duration, IgM rheumatoid factor, antibodies to cyclic citrullinated peptide, C-reactive protein, erythrocyte sedimentation rate) were recorded at baseline. Socioeconomic status, smoking status, comorbid condition, other autoimmune conditions and drug therapy were also recorded. Associations were analyzed using univariate statistics and multivariate linear regression models. Mediation tests were also carried out for evaluating the relationship between gender, height and disease measures.

Results

In males, height was inversely associated with DAS28, MJS and HAQ (at baseline and over 24 months) independent of other factors (e.g. weight, body mass index, age, disease duration, osteoporosis, autoantibodies, erosive disease, joint replacement, steroid use, smoking status, socioeconomic status and comorbid disease). In females, a similar trend was seen but the relationships were non significant. In the whole population, the association of female gender with more active disease and poor function disappeared after adjustment for height. Mediation analysis indicated that height served as a full mediator in the relationship of gender with disease activity and overall disability. Confirmation of these findings was demonstrated in a second RA population (n = 288).

Conclusion

Adult height is inversely associated with disease activity, impairment of joint function and overall disability in RA, particularly in males. The association of female sex with more severe disease activity and disability appears to be mediated by smaller stature.

Body size in relation to incidence of subtypes of haematological malignancy in the prospective Million Women Study

Background:

Greater adiposity and height have been associated with increased risk of haematological malignancies. Associations for disease subtypes are uncertain.

Methods:

A cohort of 1.3 million middle-aged UK women was recruited in 1996–2001 and followed for 10 years on average. Potential risk factors were assessed by questionnaire. Death, emigration, and incident cancer were ascertained by linkage to national registers. Adjusted relative risks were estimated by Cox regression.

Results:

During follow-up, 9162 participants were diagnosed with lymphatic or haematopoietic cancers. Each 10 kg m⁻² increase in body mass index was associated with relative risk of 1.20 (95% confidence interval: 1.13–1.28) for lymphoid and 1.37 (1.22–1.53) for myeloid malignancy (P=0.06 for heterogeneity); similarly, Hodgkin lymphoma 1.64 (1.21–2.21), diffuse large B-cell lymphoma 1.36 (1.17–1.58), plasma cell neoplasms 1.21 (1.06–1.39), acute myeloid leukaemia 1.47 (1.19–1.81), and myeloproliferative/myelodysplastic syndromes 1.32 (1.15–1.52). Each 10 cm increase in height was associated with relative risk of 1.21 (1.16–1.27) for lymphoid and 1.11 (1.02–1.21) for myeloid malignancy (P=0.07 for heterogeneity); similarly, mature T-cell malignancies 1.36 (1.03–1.79), diffuse large B-cell lymphoma 1.28 (1.14–1.43), follicular lymphoma 1.28 (1.13–1.44), plasma cell neoplasms 1.12 (1.01–1.24), chronic lymphocytic leukaemia/small lymphocytic lymphoma 1.23 (1.08–1.40), and acute myeloid leukaemia 1.22 (1.04–1.42). There was no significant heterogeneity between subtypes.

Conclusion:

In middle-aged women, greater body mass index and height were associated with modestly increased risks of many subtypes of haematological malignancy.

Identifying opportunities for cancer prevention during preadolescence and adolescence: puberty as a window of susceptibility

PURPOSE

Early life exposures during times of rapid growth and development are recognized increasingly to impact later life. Epidemiologic studies document an association between exposures at critical windows of susceptibility with outcomes as diverse as childhood and adult obesity, timing of menarche, and risk for hypertension or breast cancer.

METHODS

This article briefly reviews the concept of windows of susceptibility for providers who care for adolescent patients.

RESULTS

The theoretical bases for windows of susceptibility is examined, evaluating the relationship between pubertal change and breast cancer as a paradigm, and reviewing the underlying mechanisms, such as epigenetic modification.

CONCLUSIONS

The long-term sequela of responses to early exposures may impact other adult morbidities; addressing these exposures represents an important challenge for contemporary medicine.

Reproductive capability is associated with lifespan and cause of death in companion dogs

Reproduction is a risky affair; a lifespan cost of maintaining reproductive capability, and of reproduction itself, has been demonstrated in a wide range of animal species. However, little is understood about the mechanisms underlying this relationship. Most cost-of-reproduction studies simply ask how reproduction influences age at death, but are blind to the subjects' actual causes of death. Lifespan is a composite variable of myriad causes of death and it has not been clear whether the consequences of reproduction or of reproductive capability influence all causes of death equally. To address this gap in understanding, we compared causes of death among over 40,000 sterilized and reproductively intact domestic dogs, Canis lupus familiaris. We found that sterilization was strongly associated with an increase in lifespan, and while it decreased risk of death from some causes, such as infectious disease, it actually increased risk of death from others, such as cancer. These findings suggest that to understand how reproduction affects lifespan, a shift in research focus is needed. Beyond the impact of reproduction on when individuals die, we must investigate its impact on why individuals die, and subsequently must identify the mechanisms by which these causes of death are influenced by the physiology associated with reproductive capability. Such an approach may also clarify the effects of reproduction on lifespan in people.

Obesity and cancer--the update 2013

Progress of the last five years regarding "Obesity and Cancer" with preference to cohort studies was reviewed for cancer of the colorectum, breast, endometrium, renal cell, and adenocarcinomas of the esophagus and compared to the knowledge reviewed in the year 2008. The new studies are mostly confirming what has been known also 5 years ago. Gender seems to play a role in colorectal cancer in that risk due to body fatness is much lower in women than in men. Body fatness at young adulthood is particularly related to risk of renal cancer whereas attained body fatness at a later stage of adulthood is driving the risk for postmenopausal breast and endometrial cancer. Fat distribution is playing a strong role for risk of adenocarcinoma of the esophagus and to a lesser extent also for colon cancer. Prediagnostic body fatness plays also a role in cancer recurrence and survival.

Physical activity, occupational sitting time, and colorectal cancer risk in the Netherlands cohort study

We investigated occupational energy expenditure and sitting time in the longest held job (in men only), nonoccupational physical activity, and former sports participation in relation to colorectal cancer endpoints. The Netherlands Cohort Study includes 120,852 participants who completed a self-administered questionnaire in 1986 when they were aged 55-69 years. By 2002, 1,819 male and 1,366 female colorectal cancer cases were available for case-cohort analyses. In men, higher occupational energy expenditure levels and fewer occupational sitting hours were associated with decreased hazard ratios for colon cancer, particularly distal colon cancer (occupational energy expenditure of ≥12 vs. <8 kJ/minute, hazard ratio (HR) = 0.71, 95% confidence interval (CI): 0.52, 0.97; P for trend = 0.01; occupational sitting hours of <2 vs. 6-8 hours/day, HR = 0.63, 95% CI: 0.48, 0.83; P for trend = 0.001). The median duration of the longest held job for male subcohort members was 29 years. Nonoccupational physical activity was inconsistently associated with colorectal cancer endpoints in men, and it was inversely associated with colon cancer in women, particularly distal colon cancer (>90 vs. ≤30 minutes/day, HR = 0.69, 95% CI: 0.50, 0.96; P for trend = 0.06), and rectal cancer (>90 vs. ≤30 minutes/day, HR = 0.59, 95% CI: 0.39, 0.90; P for trend = 0.02). In conclusion, regular long-term physical activity and fewer sitting hours may protect against colon cancer, particularly distal colon cancer; results for rectal cancer were mixed.

Anthropometrics, body shape over 12 years and risk of cancer events in pre- and post-menopausal women

Studies of anthropometry and cancer have focused on body mass index (BMI). Relations between weight, waist (WC) and hip circumferences (HC), birth length and adult height with cancer are less well studied. Women from the French E3N study, born between 1925 and 1950, were followed biennially from 1995 until 2008. Body shape was classed into four groups based on median WC and HC at baseline. Hazard ratios (HRs) were estimated by Cox proportional hazards regression models. Over the 12 years of follow-up, 7,247 of 63,798 women developed cancer. As WC increased, we found a trend for decreasing cancer risk in pre-menopausal women, which reversed to an increasing risk in post-menopausal women. This remained unchanged after further adjustment for HC /or height [HR: 0.72 (0.52-1.00) before menopause and 1.17 (1.04-1.31) in the 5th vs. 1st quintile of HC], and were similar after exclusion of breast cancer. We showed that large body shape decreased cancer risk before menopause and increased it after [HR: 0.87 (0.73-1.02) and 1.11 (1.04-1.17), respectively, in women with large waist and hips compared to small waist and hips]. Adult height was associated with an non-significant increase in cancer in pre-menopause and a significant cancer risk in menopause, independent of other anthropometric characteristics [5th vs. 1st quintile [HR: 1.24 (0.98-1.56) and 1.20 (1.10-1.30)], respectively as was long birth length in post-menopausal women [HR: 1.18 (1.07-1.30) compared to medium birth length]. These results suggest independent roles of height and WC on cancer risk, through different pathways.

Human height genes and cancer

Body development requires the ability to control cell proliferation and metabolism, together with selective 'invasive' cell migration for organogenesis. These requirements are shared with cancer. Human height-associated loci have been recently identified by genome-wide SNP-association studies. Strikingly, most of the more than 100 genes found associated to height appear linked to neoplastic growth, and impose a higher risk for cancer. Height-associated genes drive the HH/PTCH and BMP/TGFβ pathways, with p53, c-Myc, ERα, HNF4A and SMADs as central network nodes. Genetic analysis of body-size-affecting diseases and evidence from genetically-modified animals support this model. The finding that cancer is deeply linked to normal, body-plan master genes may profoundly affect current paradigms on tumor development.

Childhood infectious disease and premature death from cancer: a prospective cohort study

Studies of the association between early life infections and cancer have produced inconsistent findings, possibly due to limited adjustment for confounding and retrospective designs. This study utilised data from the Newcastle Thousand Families Study, a prospective cohort of 1,142 individuals born in Newcastle-upon-Tyne in 1947, to assess the impact of various childhood infectious diseases on cancer mortality during ages 15-60 years. Detailed information was collected prospectively on a number of early life factors. Deaths from cancer during ages 15-60 years were analysed in relation to childhood infections, adjusting for potential early-life confounders, using Cox proportional-hazards regression. In a subsample who returned questionnaires at aged 49-51 years, additional adjustment was made for adult factors to predict death from cancer during ages 50-60 years. Childhood history of measles and influenza, were both independently associated with lower cancer mortality during ages 15-60 years (adjusted hazard ratios = 0.39, 95% CI 0.17-0.88 and 0.49, 95% CI 0.24-0.98 respectively). In contrast, childhood pertussis was associated with higher cancer mortality during ages 15-60 years (adjusted hazard ratio = 4.88, 95% CI 2.29-10.38). In the subsample with additional adjustment for adult variables, measles and pertussis remained significantly associated with cancer mortality during ages 50-60 years. In this pre-vaccination cohort, childhood infection with measles and influenza were associated with a reduced risk of death from cancer in adulthood, while pertussis was associated with an increased risk. While these results suggest some disease-specific associations between early-life infections and cancer, further studies are required to confirm the specific associations identified.

Association between adult height, genetic susceptibility and risk of glioma

BACKGROUND

Some, but not all, observational studies have suggested that taller stature is associated with a significant increased risk of glioma. In a pooled analysis of observational studies, we investigated the strength and consistency of this association, overall and for major sub-types, and investigated effect modification by genetic susceptibility to the disease.

METHODS

We standardized and combined individual-level data on 1354 cases and 4734 control subjects from 13 prospective and 2 case-control studies. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) for glioma and glioma sub-types were estimated using logistic regression models stratified by sex and adjusted for birth cohort and study. Pooled ORs were additionally estimated after stratifying the models according to seven recently identified glioma-related genetic variants.

RESULTS

Among men, we found a positive association between height and glioma risk (≥ 190 vs 170-174 cm, pooled OR = 1.70, 95% CI: 1.11-2.61; P-trend = 0.01), which was slightly stronger after restricting to cases with glioblastoma (pooled OR = 1.99, 95% CI: 1.17-3.38; P-trend = 0.02). Among women, these associations were less clear (≥ 175 vs 160-164 cm, pooled OR for glioma = 1.06, 95% CI: 0.70-1.62; P-trend = 0.22; pooled OR for glioblastoma = 1.36, 95% CI: 0.77-2.39; P-trend = 0.04). In general, we did not observe evidence of effect modification by glioma-related genotypes on the association between height and glioma risk.

CONCLUSION

An association of taller adult stature with glioma, particularly for men and stronger for glioblastoma, should be investigated further to clarify the role of environmental and genetic determinants of height in the etiology of this disease.

The mTOR Pathway and the Role of Energy Balance Throughout Life in Colorectal Cancer Etiology and Prognosis: Unravelling Mechanisms Through a Multidimensional Molecular Epidemiologic Approach

Timing of exposure to lifestyle factors that influence energy balance may differentially affect colorectal cancer (CRC) risk and prognosis. Caloric restriction in youth and short stature, as markers of early-life exposures, have shown to decrease CRC risk, whereas large body size and low physical activity levels in adulthood are established risk factors for CRC. Regarding prognosis, overweight, sarcopenia, and their co-occurrence (sarcopenic obesity) may negatively influence the health and quality of life of CRC survivors. There is mechanistic support for disruption of the mammalian target of rapamycin (mTOR) pathway as an underlying mechanism possibly driving these associations, because mTOR integrates signals from growth factors, nutrients, mutagens, and hormones to induce cell proliferation, resistance to apoptosis, and autophagy. However, epidemiologic evidence connecting mTOR to energy-balance-related CRC throughout the lifespan is scarce. This perspective proposes how multidimensional molecular epidemiologic studies can shed light on the etiology and prognosis of energy-balance-related CRC.

The real war on cancer: the evolutionary dynamics of cancer suppression

Cancer is a disease of multicellular animals caused by unregulated cell division. The prevailing model of cancer (multistage carcinogenesis) is based on the view that cancer results after a series of (generally somatic) mutations that knock out the genetic mechanisms suppressing unregulated cell growth. The chance of these mutations occurring increases with size and longevity, leading to Peto's paradox: why don't large animals have a higher lifetime incidence of cancer than small animals? The solution to this paradox is evolution. From an evolutionary perspective, an increasing frequency of prereproductive cancer deaths results in natural selection for enhanced cancer suppression. The expected result is a prereproductive risk of cancer across species that is independent of life history. However, within species, we still expect cancer risk to increase with size and longevity. Here, I review the evolutionary model of cancer suppression and some recent empirical evidence supporting it. Data from humans and domestic dogs confirm the expected intraspecific association between size and cancer risk, while results from interspecific comparisons between rodents provide the best evidence to date of the predicted recruitment of additional cancer suppression mechanisms as species become larger or longer lived.

Scaling of weight for height in relation to risk of cancer at different sites in a cohort of Canadian women

Many studies have examined the associations of body mass index (weight (kg)/height (m)(2)) with risk of various cancers. However, optimal scaling of weight for height may depend on the population studied. The authors used data from a large cohort study of women (Canadian National Breast Cancer Screening Study, 1980-2000; n = 89,835) to examine how the scaling of weight for height (W/H(x)) influenced the association with risk of 19 different cancers. Cox proportional hazards models were used to estimate the hazard ratio for each cancer site with W/H(x), with x increasing from 0 to 3.0 by increments of 0.1. The correlation between weight and W/H(x) decreased monotonically with increasing x, whereas W/H(x) was minimally correlated with height when x = 1.4. W/H(x) showed significant positive associations with postmenopausal breast cancer, endometrial cancer, kidney cancer, and lung cancer in never smokers. W/H(x) was inversely associated with lung cancer in ever smokers. The value of x for which W/H(x) produced the largest statistically significant hazard ratio ranged from 0.8 (endometrial cancer) to 1.7 (postmenopausal breast cancer). For lung cancer in ever smokers, the inverse association was statistically significant for all values of x. These findings suggest that the scaling of weight for height may vary depending on the cancer site and that optimal scaling may be considerably different from W/H(2) or, alternatively, that a range of scaling should be considered when examining the association of body weight with risk of disease.

Body size in relation to urinary estrogens and estrogen metabolites (EM) among premenopausal women during the luteal phase

Estrogen metabolism profiles may play an important role in the relationship between body size and breast carcinogenesis. Previously, we observed inverse associations between current body mass index (BMI) and plasma levels of parent estrogens (estrone and estradiol) among premenopausal women during both follicular and luteal phases. Using data from the Nurses' Health Study II, we assessed whether height, current BMI, and BMI at age 18 were associated with the urinary concentrations of 15 estrogens and estrogen metabolites (jointly referred to as EM) measured during the luteal phase among 603 premenopausal women. We observed inverse associations with total EM for height (P (trend) = 0.01) and current BMI (P (trend) = 0.01), but not BMI at age 18 (P (trend) = 0.26). Six EMs were 18-27% lower in women with a height 68+ versus ≤62 in., primarily in the methylated catechol pathway (P (trend) = 0.04). Eight EMs were 18-50% lower in women with a BMI of 30+ versus <20, primarily in the 2-catechol and methylated catechol pathways (P (trend) < 0.001 for both). Our results suggest that height and current BMI are associated with estrogen metabolism profiles in premenopausal women. Further studies with timed urine and blood collections are required to confirm and extend our findings.

Body mass index and renal cell cancer: the influence of race and sex

BACKGROUND

Obesity is a risk factor for renal cell (or renal) cancer. The increasing prevalence of obesity may be contributing to the rising incidence of this cancer over the past several decades. The effects of early-age obesity and change in body mass index (BMI) on renal cancer have been studied less thoroughly, and the influence of race has never been formally investigated.

METHODS

Using data gathered as part of a large case-control study of renal cancer (1214 cases and 1234 controls), we investigated associations with BMI at several time points, as well as with height. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were computed using logistic regression modeling. Race- and sex-stratified analyses were conducted to evaluate subgroup differences.

RESULTS

Obesity (BMI ≥ 30 kg/m) early in adulthood (OR = 1.6 [95% CI = 1.1 to 2.4]) and 5 years before diagnosis (1.6 [1.1 to 2.2]) was associated with renal cancer. The association with early-adult obesity was stronger among whites than blacks (test for interaction, P = 0.006), whereas the association with obesity near diagnosis was marginally stronger in women than men (test for interaction, P = 0.08). The strongest association with renal cancer was observed for obese whites both in early adulthood and before interview (2.6 [1.5 to 4.4]); this association was not present among blacks. Estimates of the annual excess rate of renal cancer (per 100,000 persons) attributed to both overweight and obesity (BMI > 25 kg/m) ranged from 9.9 among black men to 5.6 among white women.

CONCLUSION

Obesity, both early and later in life, is associated with an increased risk of renal cancer. The association with early obesity seems to be stronger among whites than blacks.

Adult height and the risk of cause-specific death and vascular morbidity in 1 million people: individual participant meta-analysis

BACKGROUND

The extent to which adult height, a biomarker of the interplay of genetic endowment and early-life experiences, is related to risk of chronic diseases in adulthood is uncertain.

METHODS

We calculated hazard ratios (HRs) for height, assessed in increments of 6.5 cm, using individual-participant data on 174374 deaths or major non-fatal vascular outcomes recorded among 1085949 people in 121 prospective studies.

RESULTS

For people born between 1900 and 1960, mean adult height increased 0.5-1 cm with each successive decade of birth. After adjustment for age, sex, smoking and year of birth, HRs per 6.5 cm greater height were 0.97 (95% confidence interval: 0.96-0.99) for death from any cause, 0.94 (0.93-0.96) for death from vascular causes, 1.04 (1.03-1.06) for death from cancer and 0.92 (0.90-0.94) for death from other causes. Height was negatively associated with death from coronary disease, stroke subtypes, heart failure, stomach and oral cancers, chronic obstructive pulmonary disease, mental disorders, liver disease and external causes. In contrast, height was positively associated with death from ruptured aortic aneurysm, pulmonary embolism, melanoma and cancers of the pancreas, endocrine and nervous systems, ovary, breast, prostate, colorectum, blood and lung. HRs per 6.5 cm greater height ranged from 1.26 (1.12-1.42) for risk of melanoma death to 0.84 (0.80-0.89) for risk of death from chronic obstructive pulmonary disease. HRs were not appreciably altered after further adjustment for adiposity, blood pressure, lipids, inflammation biomarkers, diabetes mellitus, alcohol consumption or socio-economic indicators.

CONCLUSION

Adult height has directionally opposing relationships with risk of death from several different major causes of chronic diseases.

Alcohol drinking, tobacco smoking and subtypes of haematological malignancy in the UK Million Women Study

BACKGROUND

Previous research suggests associations of lower alcohol intake and higher tobacco consumption with increased risks of haematological malignancy. The prospective Million Women Study provides sufficient power for reliable estimates of subtype-specific associations in women.

METHODS

Approximately 1.3 million middle-aged women were recruited in the United Kingdom during 1996-2001 and followed for death, emigration and cancer registration until 2009 (mean 10.3 years per woman); potential risk factors were assessed by questionnaire. Adjusted relative risks were estimated by Cox regression.

RESULTS

During follow-up, 9162 incident cases of haematological malignancy were recorded, including 7047 lymphoid and 2072 myeloid cancers. Among predominantly moderate alcohol drinkers, higher intake was associated with lower risk of lymphoid malignancies, in particular diffuse large B-cell lymphoma (relative risk 0.85 per 10 g alcohol per day (95% confidence interval 0.75-0.96)), follicular lymphoma (0.86 (0.76-0.98)) and plasma cell neoplasms (0.86 (0.77-0.96)). Among never- and current smokers, higher cigarette consumption was associated with increased risk of Hodgkin lymphoma (1.45 per 10 cigarettes per day (1.22-1.72)), mature T-cell malignancies (1.38 (1.10-1.73)) and myeloproliferative/myelodysplastic disease (1.42 (1.31-1.55)).

CONCLUSION

These findings confirm and extend existing evidence for associations of subtypes of haematological malignancy with two common exposures in women.

Adult height in relation to risk of cancer in a cohort of Canadian women

Although the influence of body mass index on cancer risk has been intensively investigated, few epidemiologic studies have examined the association of adult height with risk of cancer. We assessed the association of height with risk of all cancer and of 19 site-specific cancers in the Canadian National Breast Screening Study, a prospective cohort of nearly 90,000 women. Weight and height were measured at enrollment, and information on reproductive and medical history as well as lifestyle exposures was obtained by means of questionnaire. After exclusions, 5,679 incident invasive cancers were identified among 88,256 women. We used Cox proportional hazards model to estimate hazard ratios (HRs) and 95% confidence intervals (95% CI) per 10 cm increase in height. All tests of statistical significance were two sided. All cancers combined and ten specific sites (colorectum, colon, premenopausal breast, postmenopausal breast, endometrium, ovary, kidney, thyroid, melanoma and leukemia) showed statistically significant positive associations with height. The HR for all cancers combined was 1.13 (95% CI: 1.08-1.18), and the magnitude of the associations for specific sites ranged from HR 1.11 (95% CI: 1.03-1.20) for postmenopausal breast cancer to HR 1.51 (95% CI: 1.27-1.80) for melanoma. Our study provides strong support for a positive association of adult height with risk of certain cancers. The underlying biological mechanisms are not clear but may differ by anatomic site.

Insulin-like growth factor receptor inhibitors: baby or the bathwater?

The success of targeted therapies for cancer is undisputed; strong preclinical evidence has resulted in the approval of several new agents for cancer treatment. The type I insulin-like growth factor receptor (IGF1R) appeared to be one of these promising new targets. Substantial population and preclinical data have all pointed toward this pathway as an important regulator of tumor cell biology. Although early results from clinical trials that targeted the IGF1R showed some evidence of response, larger randomized phase III trials have not shown clear clinical benefit of targeting this pathway in combination with conventional strategies. These disappointing results have resulted in the discontinuation of several anti-IGF1R programs. However, the conduct of these trials has brought to the forefront several important factors that need to be considered in the conduct of future clinical trials. The need to develop biomarkers, a clearer understanding of insulin receptor function, and defining rational combination regimens all require further consideration. In this commentary, the current state of IGF1R inhibitors in cancer therapy is reviewed.

Leg length, sitting height and postmenopausal breast cancer risk

Background:

Tallness has consistently been associated with an increased risk of breast cancer. We investigated the association further by decomposing height into leg length and sitting height.

Methods:

From the prospective Danish cohort ‘Diet, Cancer and Health’, 23 864 postmenopausal women enrolled during 1993–1997 were followed for a diagnosis of breast cancer in the Danish Cancer Registry through 2009.

Results:

The incidence rate ratios for breast cancer were 1.11 (95% CI=1.06–1.16) for each 5 cm increase in total height and 1.09 (95% CI=1.01–1.17) and 1.14 (95% CI=1.04–1.25) for each 5 cm increase in leg length and sitting height, respectively. There was no statistical significant difference between the associations for leg length and sitting height (P=0.47).

Conclusion:

Leg length does not seem to be more strongly associated with breast cancer among postmenopausal women than sitting height.

Alterations in Brca1 expression in mouse ovarian granulosa cells have short-term and long-term consequences on estrogen-responsive organs

Incessant menstrual cycle activity, uninterrupted by either pregnancy or oral contraceptive use, is the most important risk factor for sporadic ovarian cancer. Menstrual cycle progression is partly controlled by steroid hormones such as estrogens and others that are secreted by the ovarian granulosa cells. We showed earlier that mice carrying a homozygous granulosa cell-specific knockout of Brca1, the homolog of BRCA1 that is associated with familial ovarian cancer predisposition in humans, develop benign epithelial tumors in their reproductive tract. These tumors are driven, at least in part, by a prolongation of the proestrus phase of the estrus cycle (equivalent to the follicular phase of the menstrual cycle) in Brca1 mutant mice, resulting in prolonged unopposed estrogen stimulation. Mutant mice synchronized in proestrus also showed increased circulating estradiol levels, but the possibility that this change also has a role in tumor predisposition was not investigated. We sought to determine whether these changes in hormonal stimulation result in measurable changes in tissues targeted by estrogen outside the ovary. Here we show that mice carrying a Brca1 mutation in their ovarian granulosa cells show increased endometrial proliferation during proestrus, implying that the effects of Brca1 inactivation on estrogen stimulation have short-term consequences, at least on this target organ. We further show that mutant mice develop increased femoral trabecular thickness and femoral length, which are well-known consequences of chronic estrogen stimulation. Estrogen biosynthesis by granulosa cells was increased not only in mice carrying a homozygous Brca1 mutation, but also in heterozygous mutants mimicking the mutational status in granulosa cells of human BRCA1 mutation carriers. The results suggest that human germline BRCA1 mutations, although associated with increased cancer risk, may also have beneficial consequences, such as increased bone strength, that may have contributed to the maintenance of mutated BRCA1 alleles in the human gene pool.

Postmenopausal endometrial cancer risk and body size in early life and middle age: prospective cohort study

Background:

Greater adiposity in early life has been linked to increased endometrial cancer risk in later life, but the extent to which this association is mediated through adiposity in later life is unclear.

Methods:

Among postmenopausal women who had never used menopausal hormone therapies and reported not having had a hysterectomy, adjusted relative risks (RRs) of endometrial cancer were estimated using Cox regression.

Results:

Among 249 791 postmenopausal women with 7.3 years of follow-up on average (1.8 million person-years), endometrial cancer risk (n=1410 cases) was strongly associated with current body mass index (BMI) at baseline (RR=1.87 per 5 kg m⁻² increase in BMI, 95% confidence interval (CI): 1.77–1.96). Compared with women thinner than average at age 10, the increased risk among women plumper at age 10 (RR=1.27, 95% CI: 1.09–1.49) disappeared after adjustment for current BMI (RR=0.90, 95% CI: 0.77–1.06). Similarly, compared with women with clothes size 12 or less at age 20, the increased risk among women with clothes size 16 or larger (RR=1.87, 95% CI: 1.61–2.18) was not significant after adjustment for current BMI (RR=1.03, 95% CI: 0.88–1.22).

Conclusion:

Among women who have never used hormone therapy for menopause, the association between body size in early life and endometrial cancer risk in postmenopausal women can be largely explained by women’s current BMI.

Challenges and opportunities in research on early-life events/exposures and cancer development later in life

It is becoming increasingly evident that early-life events and exposures have important consequences for cancer development later in life. However, epidemiological studies of early-life factors and cancer development later in life have had significant methodological challenges such as the long latency period, the distinctiveness of each cancer, and large number of subjects that must be studied, all likely to increase costs. These traditional hurdles might be mitigated by leveraging several existing large-scale prospective studies in the United States (US) and globally, as well as birth databases and birth cohorts, in order to launch both association and mechanistic studies of early-life exposures and cancer development later in life. Dedicated research funding will be needed to advance this paradigm shift in cancer research, and it seems justified by its potential to produce transformative understanding of how cancer develops over the life-course. This in turn has the potential to transform cancer prevention strategies through interventions in early-life rather than later in life, as is the current practice, where it is perhaps less effective.

Long-term mortality after recombinant growth hormone treatment for isolated growth hormone deficiency or childhood short stature: preliminary report of the French SAGhE study

CONTEXT

Little is known about the long-term health of subjects treated with GH in childhood, and Safety and Appropriateness of Growth hormone treatments in Europe (SAGhE) is a study addressing this question.

OBJECTIVE

The objective of the study was to evaluate the long-term mortality of patients treated with recombinant GH in childhood in France.

DESIGN

This was a population-based cohort study.

SETTING

The setting of the study was a French population-based register.

PARTICIPANTS

A total of 6928 children with idiopathic isolated GH deficiency (n = 5162), neurosecretory dysfunction (n = 534), idiopathic short stature (n = 871), or born short for gestational age (n = 335) who started treatment between 1985 and 1996 participated in the study. Follow-up data on vital status were available in September 2009 for 94.7% of the patients.

MAIN OUTCOME MEASURES

All-cause and cause-specific mortality was measured in the study.

RESULTS

All-cause mortality was increased in treated subjects [standardized mortality ratio (SMR) 1.33, 95% confidence interval (CI) 1.08-1.64]. In a multivariate analysis adjusted for height, the use of GH doses greater than 50 μg/kg · d was associated with mortality rates using external and internal references (SMR 2.94, 95% CI 1.22-7.07, hazard ratio 2.79, 95% CI 1.14-6.82). All type cancer-related mortality was not increased. Bone tumor-related mortality was increased (SMR 5.00, 95% CI 1.01-14.63). An increase in mortality due to diseases of the circulatory system (SMR 3.07, 95% CI 1.40-5.83) or subarachnoid or intracerebral hemorrhage (SMR 6.66, 95% CI 1.79-17.05) was observed.

CONCLUSIONS

Mortality rates were increased in this population of adults treated as children with recombinant GH, particularly in those who had received the highest doses. Specific effects were detected in terms of death due to bone tumors or cerebral hemorrhage but not for all cancers. These results highlight the need for additional studies of long-term mortality and morbidity after GH treatment in childhood.