National health registries - a 'goldmine' for studying non-communicable disease occurrence in Norway - the NCDNOR project.

To estimate occurrence of non-communicable diseases (NCDs) over the life-course in the Norwegian population, national health registries are a vital source of information since they fully represent the entire non-institutionalised population. However, as they are mainly established for administrative purposes, more knowledge about how NCDs are recorded in the registries is needed. To establish this, we begin by counting the number of individuals registered annually with one or more NCDs in any of the registries. The study population includes all inhabitants who lived in Norway from 2004 to 2020 (N~6.4m). The NCD outcomes are diabetes, cardiovascular diseases, chronic obstructive lung diseases, cancer and mental disorders/substance use disorders. Further, we included hip fractures in our NCD concept. The data sources used to identify individuals with NCDs, including detailed information on diagnoses in primary and secondary health care and dispensings of prescription drugs, are the Cancer Registry of Norway, The Norwegian Patient Registry, The Norwegian Control and Payment of Health Reimbursement database, and The Norwegian Prescription Database. The number of individuals registered annually with an NCD diagnosis and/or a dispensed NCD drug increased over the study period. Changes over time may reflect changes in disease incidence and prevalence, but also changes in disease-specific guidelines, reimbursement schemes and access to and use of health services. Data from more than one health registry to identify individuals with NCDs are needed since the registries reflect different levels of health care services and therefore may reflect disease severity.

Use of antihypertensive drugs and risk of cutaneous melanoma: a nationwide nested case-control study.

BACKGROUND: Most antihypertensives can induce dermal photosensitivity, which may increase melanoma risk. However, corroborating evidence is limited. We examined the associations between use of antihypertensives and melanoma risk. METHODS: A nationwide nested case-control study was conducted using data from the Cancer Registry of Norway, the National Registry and the Norwegian Prescription Database in 2004-15. Ten controls were randomly selected for each melanoma case, matched on sex and birth year. The study included 12 048 cases and 117 895 controls. We estimated rate ratios (RRs) with 95% confidence intervals (CIs). All analyses were adjusted for ambient ultraviolet radiation (UVR). We additionally performed active comparator analyses, and sensitivity analyses by only including new users, distinguishing between exclusive and mixed users, allowing for different latency periods, and subgroup analyses by melanoma subtype and clinical stage. RESULTS: Compared with non-use, we observed a slightly increased melanoma risk in users of diuretics (RR 1.08, CI 1.01-1.15), calcium-channel blockers (RR 1.10, CI 1.04-1.18) and drugs affecting the renin-angiotensin system (RR 1.10, CI 1.04-1.16), but not for beta blockers (RR 0.97, CI 0.92-1.03). We found no heterogeneity of associations by melanoma subtype or clinical stage and no dose-response relationship between the cumulative defined daily doses (DDDs) and melanoma. No interaction was found between cumulative DDDs and ambient UVR. CONCLUSIONS: Weak associations, with lack of a dose-response relationship and lack of interactions with ambient UVR, in the DDD analysis in this nationwide study do not support a causal relationship between antihypertensives and melanoma risk.

Stomach Cancer Incidence and Mortality Trends among Circumpolar Nations.

BACKGROUND: Stomach cancer incidence and mortality rates are declining across circumpolar nations, but the burden may not be distributed equally across subpopulations, including Indigenous peoples. Our objective was to examine stomach cancer incidence and mortality trends across circumpolar populations. METHODS: Cancer incidence and mortality data from 1999-2016 were obtained from the Canadian Cancer Registry, Canadian Vital Statistics, CDC WONDER, NORDCAN, Northwestern Russian cancer registries, and National Cancer Reports. The direct method was used to calculate 10-year rolling age-standardized incidence and mortality rates to the world (WHO 2000-2025) and 2011 Canadian standard populations. Standardized incidence rate ratios (SRR) were calculated. Data were stratified by sex, year, and region. U.S. data were broken down by race [White; American Indian/Alaska Native (AIAN)]. Race data were not available from non-U.S. cancer registries. RESULTS: Most populations showed declining incidence and mortality rates over time. Incidence rates among Greenland males and females, Alaska AIAN males and females, and Northern Canadian both sexes were elevated compared with regional counterparts and remained stable. The largest male SRR was observed among Alaska AIAN versus Alaska Whites [SRR = 3.82; 95% confidence interval (95% CI), 2.71-5.37]. The largest female SRR was observed among Alaska AIAN versus Alaska Whites (SRR = 4.10; 95% CI, 2.62-6.43). CONCLUSIONS: Despite stomach cancer incidence and mortality rates declining overall, some northern and Indigenous populations experience elevated and stable incidence and mortality rates. IMPACT: There is a need to address disparities observed among circumpolar subpopulations. Given similarities in incidence, mortality, and risk factor prevalence across circumpolar regions, addressing disparities could benefit from coordinated international action.

Cancer incidence in non-immigrants and immigrants in Norway.

BACKGROUND: Major cancers are associated with lifestyle, and previous studies have found that the non-immigrant populations in the Nordic countries have higher incidence rates of most cancers than the immigrant populations. However, rates are changing worldwide - so these differences may disappear with time. Here we present recent cancer incidence rates among immigrant and non-immigrant men and women in Norway and investigate whether previous differences still exist. MATERIAL AND METHODS: We took advantage of a recent change in the Norwegian Cancer Registry regulations that allow for the registry to have information on country of birth. The number of person years for 2014-2018 was aggregated for every combination of sex, five-year age-group and country of birth, by summing up each year's population in these groups. The number of cancer cases was then counted for the same groups, and age-standardised incidence rates calculated by weighing the age-specific incidence rates by the Nordic and World standard populations. Further, we calculated incidence rate ratios using the non-immigrant population as a reference. RESULTS: Immigrants from Eastern Europe, the Middle East, Africa and Asia had lower incidence of total cancer compared to the non-immigrant population in Norway and immigrants born in the other Nordic or high-income countries. However, some cancers were more common in certain immigrant groups. Asian men and women had threefold the incidence of liver cancer than non-immigrant men and women. Men from the other Nordic countries and from Eastern Europe had higher lung cancer rates than non-immigrant men. CONCLUSION: National registries should continuously monitor and present cancer incidence stratified on important population subgroups such as country of birth. This can help assess population subgroup specific needs for cancer prevention and treatment, and could eventually help reduce the morbidity and mortality of cancer.

Pre-diagnostic body mass index and weight change in relation to colorectal cancer survival among incident cases from a population-based cohort study.

BACKGROUND: Whether excess body weight influences colorectal cancer (CRC) survival is unclear. We studied pre-diagnostic body mass index (BMI) and weight change in relation to CRC-specific mortality among incident CRC cases within a large, Norwegian cohort. METHODS: Participants' weight was measured at health examinations up to three times between 1974 and 1988. CRC cases were identified through linkage with the Norwegian Cancer Registry. In total, 1336 men and 1180 women with a weight measurement >3 years prior to diagnosis were included in analyses. Hazard ratios (HRs) and confidence intervals (CIs) were estimated with Cox regression. RESULTS: During a mean follow-up of 5.8 years, 507 men and 432 women died from CRC. Obesity (BMI ≥30 kg/m(2)) was associated with higher CRC-specific mortality than normal weight (BMI 18.5-25 kg/m(2)) in men with proximal colon cancer, HR = 1.85 (95 % CI 1.08-3.16) and in women with rectal cancer, HR = 1.93 (95 % CI 1.13-3.30). Weight gain was associated with higher CRC-specific mortality in women with CRC, colon cancer, and distal colon cancer, HRs per 5 kg weight gain were 1.18 (95 % CI 1.01-1.37), 1.22 (95 % CI 1.02-1.45), and 1.40 (95 % CI 1.01-1.95), respectively. Weight gain was not significantly associated with survival in men. CONCLUSIONS: Maintaining a healthy weight may benefit CRC survival, at least in women.

Body mass index, physical activity, and colorectal cancer by anatomical subsites: a systematic review and meta-analysis of cohort studies.

Several studies report varying incidence rates of cancer in subsites of the colorectum, as an increasing proportion appears to develop in the proximal colon. Varying incidence trends together with biological differences between the colorectal segments raise questions of whether lifestyle factors impact on the risk of cancer differently at colorectal subsites. We provide an updated overview of the risk of cancer at different colorectal subsites (proximal colon, distal colon, and rectum) according to BMI and physical activity to shed light on this issue. Cohort studies of colorectal cancer, published in English throughout 2010, were identified using PubMed. The risk estimates from 30 eligible studies were summarized for BMI and physical activity. A positive relationship was found between BMI and cancer for all colorectal subsites, but most pronounced for the distal colon [relative risk (RR) 1.59, 95% confidence interval (CI) 1.34-1.89]. For the proximal colon and rectum, the risk estimates were 1.24 (95% CI 1.08-1.42) and 1.23 (95% CI 1.02-1.48), respectively. Physical activity was related inversely to the risk of cancer at the proximal (RR 0.76, 95% CI 0.70-0.83) and distal colon (RR 0.77, 95% CI 0.71-0.83). Such a relationship could not be established for the rectum (RR 0.98, 95% CI 0.88-1.08). In conclusion, the results suggest minor differences in the associations of BMI and the risk of cancer between the colorectal subsites. For physical activity, the association does not seem to differ between the colonic subsites, but a difference was observed between the colon and the rectum, perhaps indicating that different mechanisms are operating in the development of colon and rectal cancer.

Impact of colorectal cancer screening on future lifestyle choices: a three-year randomized controlled trial.

BACKGROUND & AIMS: A potential downside of colorectal cancer screening is that a "health certificate effect" might have negative effects on lifestyle. The aim of the present randomized controlled trial was to evaluate lifestyle changes in a group of individuals offered flexible sigmoidoscopy screening compared with a control group and also in relation to screening outcome. METHODS: Men and women aged 50-55 years were drawn by randomization from the population registry to be invited for flexible sigmoidoscopy screening (n = 6961) or not to be invited (n = 7000). Both groups were asked to fill in a questionnaire on selected lifestyle indicators at baseline and 3 years later. From both rounds, 3598 pairs of completed questionnaires were available for analysis from the screening group and 3462 from the control group. RESULTS: Both groups revealed a desirable change in most lifestyle indicators. A weight gain in the screening group was, on average, 0.24 kg higher than in the control group (P = .023). The screening group had poorer improvement in score for smoking (mean difference, 0.05; P = .013) and exercise habits (mean difference, -0.12; P = .001) and a lower increase in servings/day of fruit, berries, and vegetables (mean difference, -0.10; P = .001) compared with controls. The weight gain in screen-negative individuals (ie, no neoplasia) was, on average, 0.5 kg (P = .020) more than for screen positives. CONCLUSIONS: The present study has demonstrated a possible health certificate effect of flexible sigmoidoscopy screening and screening outcome on lifestyle. Although modest, these findings indicate a potential need for patient education in screening programs.

Lifestyle as a predictor for colonic neoplasia in asymptomatic individuals.

BACKGROUND: Lifestyle is a well-established risk factor for colorectal cancer (CRC) and is also found to be associated with occurrence of adenomas. In the present study we evaluated risk factors for both low-risk adenomas and advanced neoplasia in asymptomatic individuals using a single-paged questionnaire. Aiming to see if the questionnaire was a useful tool in picking up high-risk individuals. METHODS: A cross-sectional study was carried out within a randomised controlled colorectal cancer screening trial (n = 6961). The population comprised men and women born between 1946 and 1950. Before screening in year 2001 they were asked to fill in a questionnaire about their present lifestyle. Cases were categorised according to the most severe findings at screening. Analyses were then conducted to find risk factors associated with the presence of either low-risk adenomas or advanced neoplasia. RESULTS: The response rate among attendees was 97% (3998/4111). Among these, 3447 (86%) had no neoplasia, 443 (11%) had low-risk adenomas, and 108 (3%) had advanced neoplasia. Low-risk adenomas were significantly associated with current smoking, and obesity. Participants with advanced neoplasia had a two-fold increased risk of not adhering to any of the selected lifestyle recommendations compared to controls. However, current smoking was the only variable that reached statistical significance in the multivariate analysis for these lesions. A dose-response relationship to the consumption of cigarettes per day was shown, where OR was 2.04 (CI 1.07-3.89) for the lowest consumption category. CONCLUSION: The present findings indicate that a short questionnaire may be adequate in picking up the most consistent associations between lifestyle risk factors and colorectal neoplasia. Smoking and BMI were found to be the most significant risk factors for neoplasia, but adhering to recommendations on diet, and physical activity seems also to be of importance.

Lifestyle characteristics among participants in a Norwegian colorectal cancer screening trial.

The aim of the present study was to evaluate to what extent lifestyle-related variables predict participation for flexible sigmoidoscopy (FS) screening when the compliance is relatively high. During 2001, a randomized sample of 6961 men and women, born between 1946 and 1950, were invited to have a flexible sigmoidoscopy screening examination. Attendees (n = 4111) were asked to fill in a questionnaire focusing on physical activity, body weight, smoking habits and diet. The questionnaire was sent by mail to non-attendees (n = 2628) and a randomized corresponding control group not invited to screening (n = 7000). Sixty-one percent attended for screening. The questionnaire response rate among attendees, non-attendees and controls was 97, 11 and 61%, respectively. Attendees were more physically active (P < 0.001), and showed more adherence to general dietary recommendations, compared with controls. Opposing their healthy exercise and dietary habits, however, attendees were more likely to be moderate smokers compared with controls. The present offer of FS screening, achieving a relatively high compliance rate, may have reached attendees using screening as a supplement to an already healthy lifestyle, but also those who seek amelioration through health checks for risks behaviour that they are perfectly well aware of, such as smoking.