Long-Term Exposure to Walkable Residential Neighborhoods and Risk of Obesity-Related Cancer in the New York University Women's Health Study (NYUWHS)

BACKGROUND

Living in neighborhoods with higher levels of walkability has been associated with a reduced risk of obesity and higher levels of physical activity. Obesity has been linked to increased risk of 13 cancers in women. However, long-term prospective studies of neighborhood walkability and risk for obesity-related cancer are scarce.

OBJECTIVES

We evaluated the association between long-term average neighborhood walkability and obesity-related cancer risk in women.

METHODS

The New York University Women's Health Study (NYUWHS) is a prospective cohort with 14,274 women recruited between 1985 and 1991 in New York City and followed over nearly three decades. We geocoded residential addresses for each participant throughout follow-up and calculated an average annual measure of neighborhood walkability across years of follow-up using data on population density and accessibility to destinations associated with geocoded residential addresses. We used ICD-9 codes to characterize first primary obesity-related cancers and employed Cox proportional hazards models to assess the association between average neighborhood walkability and risk of overall and site-specific obesity-related cancers.

RESULTS

Residing in neighborhoods with a higher walkability level was associated with a reduced risk of overall and site-specific obesity-related cancers. The hazards ratios associated with a 1-standard deviation increase in average annual neighborhood walkability were 0.88 (95% CI: 0.85, 0.93) for overall obesity-related cancer, 0.89 (95% CI: 0.84, 0.95) for postmenopausal breast cancer, 0.82 (95% CI: 0.68, 0.99) for ovarian cancer, 0.87 (95% CI: 0.76, 0.99) for endometrial cancer, and 0.68 (95% CI: 0.49, 0.94) for multiple myeloma, adjusting for potential confounders at both the individual and neighborhood level. The association between neighborhood walkability and risk of overall obesity-related cancer was stronger among women living in neighborhoods with higher levels of poverty compared with women living in areas with lower poverty levels (p Interaction = 0.006 ).

DISCUSSION

Our study highlights a potential protective role of neighborhood walkability in preventing obesity-related cancers in women. https://doi.org/10.1289/EHP11538.

Non-occupational physical activity and risk of cardiovascular disease, cancer and mortality outcomes: a dose-response meta-analysis of large prospective studies

OBJECTIVE

To estimate the dose-response associations between non-occupational physical activity and several chronic disease and mortality outcomes in the general adult population.

DESIGN

Systematic review and cohort-level dose-response meta-analysis.

DATA SOURCES

PubMed, Scopus, Web of Science and reference lists of published studies.

ELIGIBILITY CRITERIA

Prospective cohort studies with (1) general population samples >10 000 adults, (2) ≥3 physical activity categories, and (3) risk measures and CIs for all-cause mortality or incident total cardiovascular disease, coronary heart disease, stroke, heart failure, total cancer and site-specific cancers (head and neck, myeloid leukaemia, myeloma, gastric cardia, lung, liver, endometrium, colon, breast, bladder, rectum, oesophagus, prostate, kidney).

RESULTS

196 articles were included, covering 94 cohorts with >30 million participants. The evidence base was largest for all-cause mortality (50 separate results; 163 415 543 person-years, 811 616 events), and incidence of cardiovascular disease (37 results; 28 884 209 person-years, 74 757 events) and cancer (31 results; 35 500 867 person-years, 185 870 events). In general, higher activity levels were associated with lower risk of all outcomes. Differences in risk were greater between 0 and 8.75 marginal metabolic equivalent of task-hours per week (mMET-hours/week) (equivalent to the recommended 150 min/week of moderate-to-vigorous aerobic physical activity), with smaller marginal differences in risk above this level to 17.5 mMET-hours/week, beyond which additional differences were small and uncertain. Associations were stronger for all-cause (relative risk (RR) at 8.75 mMET-hours/week: 0.69, 95% CI 0.65 to 0.73) and cardiovascular disease (RR at 8.75 mMET-hours/week: 0.71, 95% CI 0.66 to 0.77) mortality than for cancer mortality (RR at 8.75 mMET-hours/week: 0.85, 95% CI 0.81 to 0.89). If all insufficiently active individuals had achieved 8.75 mMET-hours/week, 15.7% (95% CI 13.1 to 18.2) of all premature deaths would have been averted.

CONCLUSIONS

Inverse non-linear dose-response associations suggest substantial protection against a range of chronic disease outcomes from small increases in non-occupational physical activity in inactive adults. PROSPERO registration number CRD42018095481.

Baseline quality of life and chemotherapy toxicities in patients with early breast cancer

BACKGROUND

The authors used the French breast cancer Cancer and Toxicities (CANTO) cohort to study the associations between baseline quality of life and chemotherapy dose-reductions (CDRs) or postchemotherapy-toxicities (PCTs).

METHODS

In total, 3079 patients with breast cancer who received chemotherapy were included in this analysis. The associations between baseline physical functioning (PF) and fatigue measured using the European Organization for Research and Treatment of Cancer Quality-of-Life Questionnaire Core 30, and two endpoints-CDRs during adjuvant or neoadjuvant chemotherapy; and selected PCTs were estimated with odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) using logistic regression models.

RESULTS

Among the 3079 patients from the CANTO cohort who were included, 718 (33.0%) received chemotherapy in the neoadjuvant setting, and 2361 (67.0%) received chemotherapy as adjuvant treatment. The chemotherapy included taxanes in 94.2% of patients and anthracyclines in 90.5% of patients. Overall, 15.5% of patients experienced CDRs and, 31.0% developed PCTs. Women with low baseline PF scores (<83) had higher multivariate odds of developing CDRs compared with those who had PF scores ≥83 (OR, 1.54; 95% CI, 1.13-2.09). The corresponding OR for PCTs was 1.50 (95% CI, 1.13-2.00). Women with high baseline fatigue scores had higher odds of CDRs (OR, 1.43; 95% CI, 1.13-1.76) and PCTs (OR, 1.32; 95% CI, 1.10-1.59).

CONCLUSIONS

By using the national CANTO cohort, baseline PF and fatigue were independently associated with CDRs and PCTs.

Life-Course Trajectories of Physical Activity and Melanoma Risk in a Large Cohort of Norwegian Women

Purpose

Physical activity (PA) is a cornerstone in disease prevention and varies throughout life. A pooled analysis of cohort studies and a meta-analysis of cohort studies found positive associations between PA and melanoma risk. However, previous studies focused on PA at specific ages and often lacked information on ultraviolet radiation (UVR) exposure. Using the population-based Norwegian Women and Cancer (NOWAC) cohort, including information on PA and UVR exposure, we estimated life-course PA trajectories from adolescence to adulthood and their associations with melanoma.

Methods

Total PA across different domains (recreation, occupation, transport, household) was reported for ages 14 and 30 years, and when responding to the questionnaire (31-76 years) using a 10-point scale, validated to rank PA levels in Norwegian females. We estimated life-course PA trajectories using a latent class mixed model in 152,248 women divided into three subcohorts depending on age at questionnaire completion: 31-39 (n = 27,098), 40-49 (n = 52,515) and ≥50 years (n = 72,635). The unique 11-digit identity number of Norwegian citizens was used to link NOWAC to the Cancer Registry of Norway for information on cancer diagnoses, emigration and death. Associations between PA trajectories and melanoma risk were estimated in each subcohort using multivariable Cox regression.

Results

Five classes of individual life-course PA trajectories were identified in subcohort 31-39 years (low, moderate, high, decreasing, increasing PA) and four in subcohorts 40-49 and ≥50 years (low, moderate, high, decreasing PA). No significant association was found between life-course PA trajectories and melanoma risk in any subcohort. Hazard ratios (95% confidence intervals) for the high versus moderate trajectory were 0.92 (0.66-1.29), 1.15 (0.97-1.37) and 0.90 (0.78-1.05) for subcohorts 31-39, 40-49 and ≥50 years, respectively.

Conclusion

Our results do not support a positive association between PA and melanoma risk found in previous studies, which is important for public health guidelines promoting regular PA.

Physical activity in Sami and non-Sami populations in rural Northern Norway, the SAMINOR 2 Clinical Survey

Background

The Sami people is an indigenous minority population living in the northern parts of Norway and mainly in rural areas. We lack data of contemporary levels of physical activity (PA) in rural regions of Northern Norway and in the Sami population in particular. We aimed to describe the PA levels and investigate whether PA levels differs between Sami and non-Sami and between coastal and inland areas.

Methods

We used data from the second survey of the Population-based Study on Health and Living Conditions in Regions with Sami and Norwegian Populations – the SAMINOR 2 Clinical Survey (2012–2014) that includes the adult population in 10 municipalities in the counties Troms, Finnmark and Nordland. Participants self-reported on PA, ethnicity and modifiable lifestyle factors. Twelve thousand four hundred fifty-five individuals were invited with a response rate of 48.2% (n = 6004 participants). We tested differences using chi-square tests, two sample t-tests and linear regression models.

Results

Among 5628 participants, 41.1 and 40.9% of men and women, respectively, were defined as Sami. We found no ethnic differences in PA in men overall. However, Sami men living in Tana, and Nesseby reported higher PA compared to non-Sami men in the same area. For Sami women there was overall lower PA levels compared to non-Sami women, especially pronounced in Kautokeino/ Karasjok.

Conclusion

This study showed small differences in PA levels between Sami and non-Sami men. Sami women had lower PA levels compared to their non-Sami counterparts. It is important to identify whether there are differences in various ethnic populations, together with other predictors for PA in future planning of public health interventions.

Why exercise has a crucial role in cancer prevention, risk reduction and improved outcomes

INTRODUCTION

Exercise is one of several factors known to lower the risk of developing cancer, as well as improve outcomes in patients already diagnosed. People who exercise after cancer have lower rates of cancer complications, treatment toxicities, relapse and improved survival. This review highlights the supportive data and biochemical processes, which explain these potential benefits.

SOURCES OF DATA

PubMed, Embase, Medline and Cochrane libraries were searched for papers which addressed the effects of exercise and physical activity on cancer for this review. The search terms used were physical activity, exercise and cancer up to February 2021. We also referred to the background research required for international exercise intervention study involving men with prostate cancer (INTERVAL-GAP4) and scrutinized references within the robust papers published on this subject to ensure we did not miss any clinically studies. One hundred and eighty eight papers were included.

AREAS OF AGREEMENT

Exercise programmes mitigate many of the complications and risks associated with cancer, particularly thromboembolism, fatigue, weight gain, arthralgia, cognitive impairment and depression.

AREAS OF CONTROVERSY

Molecular and biomarker changes, resulting from exercise, suggest that exercise elicits beneficial changes in insulin-related pathways, down-regulates inflammation and serum oestrogen levels, and enhances oxidative, immune and cellular repair pathways. Nonetheless, the evidence remains preliminary.

GROWING POINTS

The timing, intensity and challenges of prehabilitation, adjunct and rehabilitation exercise programmes are being increasingly understood but their implementation remains sporadic.

AREAS FOR DEVELOPING RESEARCH

More robust clinical trial data are needed to substantiate a causal effect of exercise on overall and cancer-specific survival. These studies are ongoing. Research evaluating the most cost-efficient ways of incorporating prehabilitation, adjunct and rehabilitation programmes into routine practice would be helpful to funding bodies and health care strategists.

Combined Lifestyle Behaviors and the Incidence of Common Cancer Types in the Norwegian Women and Cancer Study (NOWAC)

INTRODUCTION

Only a small number of studies have examined the impact of combined lifestyle behaviors on cancer incidence, and never in a Norwegian population.

PURPOSE

To examine linear and nonlinear associations of combined lifestyle factors, assessed through a healthy lifestyle index (HLI), with the incidence of postmenopausal breast, colorectal, lung, postmenopausal endometrial, postmenopausal ovarian, pancreatic, and kidney cancer among women in Norway.

METHODS

This prospective study included 96,869 women enrolled in the Norwegian Women and Cancer (NOWAC) cohort. Baseline information on lifestyle factors was collected between 1996 and 2004. The HLI was constructed from five lifestyle factors: physical activity level, body mass index, smoking, alcohol consumption, and diet. Each factor contributed 0 to 4 points to the HLI score, which ranged from 0 to 20, with higher scores representing a healthier lifestyle. Multiple imputation was used to handle missing data. Cox proportional hazard regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI). Restricted cubic splines were used to examine nonlinearity in the associations.

RESULTS

The HRs for a one-point increment on the HLI score were 0.97 (95% CI: 0.96-0.98) for postmenopausal breast cancer, 0.98 (0.96-1.00) for colorectal cancer, 0.86 (0.84-0.87) for lung cancer, 0.93 (0.91-0.95) for postmenopausal endometrial cancer, 0.99 (0.96-1.02) for postmenopausal ovarian cancer, 0.92 (0.89-0.95) for pancreatic cancer, and 0.94 (0.91-0.97) for kidney cancer. Nonlinearity was observed for the inverse associations between HLI score and the incidence of lung cancer and postmenopausal breast cancer.

CONCLUSION

Based on our results, healthier lifestyle, as assessed by the HLI score, was associated with lower incidence of postmenopausal breast, colorectal, lung, postmenopausal endometrial, pancreatic, and kidney cancer among women, although the magnitude and linearity varied. Adoption of healthier lifestyle behaviors should be a public health priority to reduce the cancer burden among Norwegian women.

Excess Body Weight and Incidence of Type 1 and Type 2 Endometrial Cancer: The Norwegian Women and Cancer Study

PURPOSE

Excess body weight has been associated with increased risk of 13 cancer types and is a particularly strong risk factor for endometrial cancer (EC). Only a few previous studies have assessed the relationship between excess body weight and EC subtypes. In this study, we aimed to investigate the associations between excess weight and incidence of type 1 and type 2 EC.

PATIENTS AND METHODS

We used data from 151,537 participants in the Norwegian Women and Cancer (NOWAC) cohort of which 935 were diagnosed with type 1 and 263 with type 2 EC during follow-up. Height and body weight were self-reported. Multivariable Cox proportional hazard regression was used to assess the associations between body mass index (BMI) and type 1 and type 2 EC.

RESULTS

For every 2 kg/m2 increase in BMI, the risk of type 1 EC increased by 21% (HR=1.21, 95% CI: 1.18, 1.24) and the risk of type 2 EC by 10% (HR=1.10, 95% CI: 1.03, 1.16) (pheterogeneity = 0.009). During the period 1991 to 2016, 24.0% (95% CI: 20.0% to 27.8%) of type 1 EC cases was attributable to excess body weight. Avoiding obesity could have prevented 6.6% (95% CI: 3.4% to 9.7%) of type 2 EC cases.

CONCLUSION

Excess body weight was associated with both type 1 and type 2 EC in a dose-dependent manner and the association was significantly stronger in type 1 EC. These findings could support the hypothesis that estrogen plays a more important role in the development of type 1 ECs than in type 2 EC.

Prevention of gynecological cancers: the affecting factors and knowledge levels of Turkish women

Purpose

Gynecological cancers are preventable and treatable diseases in case of early diagnosis. However, lack of knowledge is one of the factors preventing women from benefiting from early diagnosis. Increasing women's knowledge of gynecological cancers contributes to improving the health of both women and the community. The purpose of this research study was to determine the affecting factors and knowledge level of Turkish women-related gynecological cancer prevention.

Design/methodology/approach

This was a cross-sectional descriptive study and was carried out at a state hospital's outpatient clinic between May and June 2019. The sampling included 496 women who are not diagnosed with gynecological cancer in the individual or in the family. Data were collected using the personal information form and Gynecological Cancer Prevention Information Scale (GCPIS). Data were evaluated using the SPSS 22.0 software program. Frequencies, mean and standard deviation were used for the descriptive variables. For the data that met the parametric conditions, those with two groups were analyzed using independent samplest-tests and those with more than two groups were analyzed usingF-test.

Findings

In this study, the GCPIS total mean score of women was found 16.22 ± 8.21 (min: 0, max: 35). A statistically significant difference was found between the women's level of knowledge according to the age group of the participants, education level, economic status perception, regular pap-smear test, regular vulva examination and getting information about prevention from gynecologic cancers (p < 0.05).

Research limitations/implications

This study was conducted on a group of Turkish women and cannot be generalized to other cultures.

Practical implications

This study can be beneficial for determining the Turkish women's knowledge levels about gynecological cancers of women and for providing data for health education programs planning to be created.

Social implications

The data of this study can be used to improve women's knowledge and examination skills of gynecological cancers. Thus, the quality of life of women can be improved.

Originality/value

Healthcare professionals can play vital roles in presenting needed knowledge about gynecological cancers and raising awareness in women. It is extremely important for women to be informed about gynecological cancers for prevention of gynecological cancers and health improvement.

Physical Activity: Impact on Survival in Gynecologic Cancer

Importance

Physical activity has many important health benefits. There is also growing evidence that physical activity plays a role in the prevention and prognosis of multiple cancers, including gynecologic malignancies. Despite the many benefits of physical activity, the number of individuals meeting physical activity recommendations remains low.

Objective

To examine the role that physical activity plays in the prevention, treatment, and prognosis of gynecologic malignancies and to review the feasibility of physical activity interventions among gynecologic cancer survivors.

Evidence Acquisition

A PubMed search was performed using relevant terms to identify journal articles related to the proposed subject. The websites of multiple national and international organizations were also used to obtain up-to-date guidelines and recommendations.

Results

Physical activity appears to decrease the risk of ovarian, endometrial, and cervical cancer, with the strongest evidence of this association seen in endometrial cancer. Although the literature is scarce, participation in physical activity is feasible during active treatment for gynecologic cancers and may decrease symptom burden and increase chemotherapy completion rates. Gynecologic cancer survivors are motivated to increase physical activity, and lifestyle intervention programs are feasible and well received among this population.

Conclusions and Relevance

Health care providers caring for women with gynecologic malignancies must counsel patients regarding the importance of physical activity. This should include a discussion of the health benefits and, specifically, the cancer-related benefits. A personalized approach to physical activity intervention is essential.

Physical Activity in Cancer Prevention and Survival: A Systematic Review

PURPOSE

This article reviews and updates the evidence on the associations between physical activity and risk for cancer, and for mortality in persons with cancer, as presented in the 2018 Physical Activity Guidelines Advisory Committee Scientific Report.

METHODS

Systematic reviews of meta-analyses, systematic reviews, and pooled analyses were conducted through December 2016. An updated systematic review of such reports plus original research through February 2018 was conducted. This article also identifies future research needs.

RESULTS

In reviewing 45 reports comprising hundreds of epidemiologic studies with several million study participants, the report found strong evidence for an association between highest versus lowest physical activity levels and reduced risks of bladder, breast, colon, endometrial, esophageal adenocarcinoma, renal, and gastric cancers. Relative risk reductions ranged from approximately 10% to 20%. Based on 18 systematic reviews and meta-analyses, the report also found moderate or limited associations between greater amounts of physical activity and decreased all-cause and cancer-specific mortality in individuals with a diagnosis of breast, colorectal, or prostate cancer, with relative risk reductions ranging almost up to 40% to 50%. The updated search, with five meta-analyses and 25 source articles reviewed, confirmed these findings.

CONCLUSIONS

Levels of physical activity recommended in the 2018 Guidelines are associated with reduced risk and improved survival for several cancers. More research is needed to determine the associations between physical activity and incidence for less common cancers and associations with survival for other cancers. Future studies of cancer incidence and mortality should consider these associations for population subgroups, to determine dose-response relationships between physical activity and cancer risk and prognosis, and to establish mechanisms to explain these associations.

The preventable burden of endometrial and ovarian cancers in Australia: A pooled cohort study

OBJECTIVE

Evidence on the endometrial and ovarian cancer burden preventable through modifications to current causal behavioural and hormonal exposures is limited. Whether the burden differs by population subgroup is unknown.

METHODS

We linked pooled data from six Australian cohort studies to national cancer and death registries, and quantified exposure-cancer associations using adjusted proportional hazards models. We estimated exposure prevalence from representative health surveys. We then calculated Population Attributable Fractions (PAFs) with 95% confidence intervals (CIs), accounting for competing risk of death, and compared PAFs for population subgroups.

RESULTS

During a median 4.9 years follow-up, 510 incident endometrial and 303 ovarian cancers were diagnosed. Overweight and obesity explained 41.9% (95% CI 32.3-50.1) of the endometrial cancer burden and obesity alone 34.5% (95% CI 27.5-40.9). This translates to 12,800 and 10,500 endometrial cancers in Australia in the next 10 years, respectively. The body fatness-related endometrial cancer burden was highest (49-87%) among women with diabetes, living remotely, of older age, lower socio-economic status or educational attainment and born in Australia. Never use of oral contraceptives (OCs) explained 8.1% (95% CI 1.8-14.1) or 2500 endometrial cancers. A higher BMI and current long-term MHT use increased, and long-term OC use decreased, the risk of ovarian cancer, but the burden attributable to overweight, obesity or exogenous hormonal factors was not statistically significant.

CONCLUSIONS

Excess body fatness, a trait that is of high and increasing prevalence globally, is responsible for a large proportion of the endometrial cancer burden, indicating the need for effective strategies to reduce adiposity.

Avoidable cancers in the Nordic countries-the potential impact of increased physical activity on postmenopausal breast, colon and endometrial cancer

BACKGROUND

Physical activity has been shown to reduce the risk of colon, endometrial and postmenopausal breast cancer. The aim of this study was to quantify the proportion of the cancer burden in the Nordic countries linked to insufficient levels of leisure time physical activity and estimate the potential for cancer prevention for these three sites by increasing physical activity levels.

METHODS

Using the Prevent macrosimulation model, the number of cancer cases in the Nordic countries over a 30-year period (2016-2045) was modelled, under different scenarios of increasing physical activity levels in the population, and compared with the projected number of cases if constant physical activity prevailed. Physical activity (moderate and vigorous) was categorised according to metabolic equivalents (MET) hours in groups with sufficient physical activity (15+ MET-hours/week), low deficit (9 to <15 MET-hours/week), medium deficit (3 to <9 MET-hours/week) and high deficit (<3 MET-hours/week).

RESULTS

If no one had insufficient levels of physical activity, about 11,000 colon, endometrial and postmenopausal breast cancer cases could be avoided in the Nordic countries in a 30-year period, which is 1% of the expected cases for the three cancer types. With a 50% reduction in all deficit groups by 2025 or a 100% reduction in the group of high deficit, approximately 0.5% of the expected cases for the three cancer types could be avoided. The number and percentage of avoidable cases was highest for colon cancer.

CONCLUSION

11,000 cancer cases could be avoided in the Nordic countries in a 30-year period, if deficit in physical activity was eliminated.

Low proportion of unreported cervical treatments in the cancer registry of Norway between 1998 and 2013

BACKGROUND

Accurate information about treatment is needed to evaluate cervical cancer prevention efforts. We studied completeness and validity of reporting cervical treatments in the Cancer Registry of Norway (CRN).

MATERIAL AND METHODS

We identified 47,423 (92%) high-grade cervical dysplasia patients with and 3983 (8%) without recorded treatment in the CRN in 1998-2013. We linked the latter group to the nationwide registry of hospital discharges in 1998-2015. Of patients still without treatment records, we randomly selected 375 for review of their medical history. Factors predicting incomplete treatment records were assessed by multiple imputation and logistic regression.

RESULTS

Registry linkage revealed that 10% (401/3983) of patients received treatment, usually conization, within one year of their initial high-grade dysplasia diagnosis. Of those, 11% (n = 44) were missing due to unreporting and 89% (n = 357) due to misclassification at the CRN. Of all cases in medical review, patients under active surveillance contributed almost 60% (223/375). Other reasons of being without recorded treatment were uncertain dysplasia diagnosis, invasive cancer or death. Coding error occurred in 19% (73/375) of randomly selected cases. CRN undercounted receipt of treatment by 38% (n = 1526) among patients without recorded treatment which translates into 97% overall completeness of treatment data. Incomplete treatment records were particularly associated with public laboratories, patients aged 40-54 years, and the latest study years.

CONCLUSIONS

CRN holds accurate information on cervical treatments. Completeness and particularly validity can be further improved through the establishment of new internal routines and regular linkage to hospital discharges.

The impact of gynaecological cancer treatment on physical activity levels: a systematic review of observational studies

BACKGROUND

The natural history of physical activity levels during and following gynaecological cancer treatment is not well understood. This is required in order to establish the time at which physical activity levels are lowest in order to target cancer rehabilitation or exercise interventions in gynaecological cancer population accordingly.

OBJECTIVES

To conduct a systematic review to evaluate the impact of gynaecological cancer treatments on physical activity levels and to summarise the pattern of changes in physical activity levels over time among patients with gynaecological cancer.

METHODS

A comprehensive literature search was performed via MEDLINE (1946-2018), CINAHL (1982-2018), EMBASE (1947-2018), Ovid Emcare (1947-2018), PsycINFO (1806-2018) and the Cochrane Library (1991-2018). Studies were eligible for inclusion if they had assessed changes in physical activity levels during and after gynaecological cancer treatment. The methodological quality of the eligible studies was assessed by two independent reviewers using the Joanna Briggs Institute Critical Appraisal Tools.

RESULTS

In total, six studies (three cohort studies and three cross-sectional studies) with 1607 participants were included. All studies used patient-reported physical activity measures. Two of the three cohort studies measured patient-recalled physical activity levels before diagnosis (baseline), and length of follow-up varied across all studies. The majority of participants were treated surgically±adjuvant therapy. Physical activity levels decreased at 6 months following surgery when compared with pre-treatment levels. Approximately 91% of participants did not meet physical activity guidelines 2 years following diagnosis, and 58% reported being less physically active 3 years after diagnosis, compared with the pre-diagnosis levels.

CONCLUSIONS

Despite the paucity of evidence and limitations in the current body of literature, this review demonstrated that compared to pre-diagnosis, levels of physical activity remain low in gynaecological cancer survivors up to 3 years after diagnosis. More research is warranted to better characterise the pattern of change of physical activity levels across the disease trajectory and identify changes in physical activity patterns by cancer treatments and gynaecological tumour streams in order to target interventions accordingly.

Lifetime number of years of menstruation as a risk index for postmenopausal endometrial cancer in the Norwegian Women and Cancer Study

INTRODUCTION

Lifetime number of years of menstruation (LNYM) reflects a woman's cumulative exposure to endogenous estrogen and can be used as a measure of the combined effect of reproductive factors related to endometrial cancer (EC) risk.

MATERIAL AND METHODS

We aimed to study the association between LNYM and EC risk among postmenopausal women and calculate the population attributable fraction of EC for different LNYM categories. Our study sample consisted of 117 589 women from the Norwegian Women and Cancer (NOWAC) Study. All women were aged 30-70 years at enrollment and completed a baseline questionnaire between 1991 and 2006. Women were followed up for EC to December 2014 through linkages to national registries. We used Cox proportional hazards models to estimate hazard ratios with 95% confidence intervals (95% CIs), adjusted for potential confounders.

RESULTS

In all, 720 women developed EC. We found a statistically significant, positive dose-response relationship between LNYM and EC, with a 9.1% higher risk for each additional year of LNYM (P for trend < .001). Using the LNYM category ≥40 as a reference, the hazard ratios for LNYM <25, 25-29, 30-34, 35-39 were 0.17 (95% CI 0.22-0.27), 0.25 (95% CI 0.17-0.36), 0.43 (95% CI 0.32-0.58), and 0.68 (95% CI 0.51-0.92), respectively. The association between LNYM and EC was independent of incomplete pregnancies, menopausal hormone therapy, diabetes, and body mass index. When considering the population attributable fraction, 67% of EC was estimated to be attributable to LNYM ≥25 years.

CONCLUSIONS

Our study supports that increasing LNYM is an important and independent predictor of EC risk.

Physical activity, sedentary behaviour, diet, and cancer: an update and emerging new evidence

The lifestyle factors of physical activity, sedentary behaviour, and diet are increasingly being studied for their associations with cancer. Physical activity is inversely associated with and sedentary behaviour is positively (and independently) associated with an increased risk of more than ten types of cancer, including colorectal cancer (and advanced adenomas), endometrial cancers, and breast cancer. The most consistent dietary risk factor for premalignant and invasive breast cancer is alcohol, whether consumed during early or late adult life, even at low levels. Epidemiological studies show that the inclusion of wholegrain, fibre, fruits, and vegetables within diets are associated with reduced cancer risk, with diet during early life (age <8 years) having the strongest apparent association with cancer incidence. However, randomised controlled trials of diet-related factors have not yet shown any conclusive associations between diet and cancer incidence. Obesity is a key contributory factor associated with cancer risk and mortality, including in dose-response associations in endometrial and post-menopausal breast cancer, and in degree and duration of fatty liver disease-related hepatocellular carcinoma. Obesity produces an inflammatory state, characterised by macrophages clustered around enlarged hypertrophied, dead, and dying adipocytes, forming crown-like structures. Increased concentrations of aromatase and interleukin 6 in inflamed breast tissue and an increased number of macrophages, compared with healthy tissue, are also observed in women with normal body mass index, suggesting a metabolic obesity state. Emerging randomised controlled trials of physical activity and dietary factors and mechanistic studies of immunity, inflammation, extracellular matrix mechanics, epigenetic or transcriptional regulation, protein translation, circadian disruption, and interactions of the multibiome with lifestyle factors will be crucial to advance this field.