Dietary patterns in adolescence and risk of colorectal cancer: a population-based study.

PURPOSE: To study whether dietary patterns in adolescence are associated with risk of colorectal cancer (CRC). METHODS: Food frequency data were obtained from the AGES-Reykjavik study, conducted between 2002 and 2006, which included 5,078 (58% women) participants with mean age of 77 (± 5.8) years. Principal component analysis was used to identify dietary patterns. Participants were followed through linkage to the Icelandic Cancer Registry. Multivariable Cox models were used to calculate hazard ratios (HR) of CRC and 95% confidence interval (CI) by dietary patterns. RESULTS: During the follow-up period (mean 8.2 years), 136 participants (75 women and 61 men) were diagnosed with CRC. The main dietary pattern in adolescence was characterized by high intake of traditional food items consumed in the earlier half of the twentieth century, namely, salted or smoked meat and fish, milk, offal, rye bread, and oatmeal. Compared to the lowest tertile, the middle tertile of this pattern was associated with increased risk of CRC (HR 1.63, 95% CI 1.04-2.57), while the highest tertile was not statistically associated with CRC (HR 1.48, 95% CI 0.93-2.37), except among women (HR 2.06, 95% CI 1.11-3.84). CONCLUSION: These data suggest that strong adherence to a traditional Icelandic diet in adolescence might increase the risk of CRC, particularly among women. More research is need on the association between food items and dietary patterns of relevance to CRC at different points in the life cycle.

Dietary intake is associated with risk of multiple myeloma and its precursor disease.

The etiology of monoclonal gammopathy of undetermined significance (MGUS), the precursor state of multiple myeloma (MM), is mostly unknown and no studies have been conducted on the effect of diet on MGUS or progression from MGUS to MM. We aimed to explore the association between common foods and MGUS and progression to MM. Data from the population-based AGES Study (N = 5,764) were utilized. Food frequency questionnaire was used to assess dietary intake during adolescence, midlife, and late life. Serum protein electrophoresis and serum free light-chain assay was performed to identify MGUS (n = 300) and LC-MGUS cases (n = 275). We cross linked our data with the Icelandic Cancer Registry to find cases of MM in the study group. We found that intake of fruit at least three times per week during adolescence was associated with lower risk of MGUS when compared to lower fruit consumption (OR = 0.62, 95% CI 0.41-0.95). We additionally found that intake of fruit at least three times per week during the late life period was associated with decreased risk of progressing from MGUS to MM (HR = 0.34, 95% CI 0.13-0.89) when compared to lower intake. Adolescent intake of fruit may reduce risk of MGUS, whereas fruit intake after MGUS onset may reduce risk of progressing to MM. Our findings suggest that diet might alter the risk of developing MGUS and progression to MM.

Correction: Dietary habits in adolescence and midlife and risk of breast cancer in older women.

[This corrects the article DOI: 10.1371/journal.pone.0198017.].

[Views of Icelandic women towards genetic counseling - and testing of BRCA2 mutations].

Introduction The aim of this study was to explore the attitudes of Icelandic women towards existing genetic information, genetic counseling and genetic testing for BRCA mutations which dramatically increase risk for aggressive cancers. Materials and methods Women attending the cancer prevention clinic in Reykjavik, capital of Iceland, from October 12th until November 20th 2015 received an invitation to participate. Participation involved answering a short online questionnaire about background, family history of cancer as well as attitudes towards genetic counseling, BRCA testing and preventive use of such information. Descriptive statistics and chi-square tests were used to describe differences in attitudes towards those questions between subgroups of women. Results 1129 women (69% response rate) answered the questionnaire. Mean age was 47 years (span 21-76 years). Around half (47%) had heard fairly much about the mutations. Independent of family history of cancer, the majority of women were positive towards receiving genetic counseling (79%) and to undergo genetic testing (83%) for BRCA mutation with younger women being more interested than older women. On the other hand, only 4% of the women had already received genetic counseling and 7% undergone genetic testing. Women with family history of cancer were more knowledgeable about BRCA mutations (p<0.0001) and were less afraid of the consequence of being a mutation carrier (p<0.0001) compared to those with little or no family history. Regardless of family history, half (49%) worried that results from genetic testing could influence their health insurance. Almost all, or 97% of the women, were positive or very positive toward using existing genetic information obtained through scientific work, to inform affected indi-viduals of their mutation status. Conclusion Icelandic women are positive towards genetic counseling and testing for BRCA mutations although half of them worry that a positive result might affect their health insurance. Nevertheless, almost all women believe that existing genetic information should be used to inform carriers for preventive purposes.

Dietary habits in adolescence and midlife and risk of breast cancer in older women.

Recent studies indicate that lifestyle factors in early life affect breast cancer risk. We therefore explored the association of high consumption of meat, milk, and whole grain products in adolescence and midlife, on breast cancer risk. We used data from the population based AGES-Reykjavik cohort (2002-2006), where 3,326 women with a mean age of 77 years (SD 6.0) participated. For food items and principal component derived dietary patterns we used Cox proportional models to calculate multivariate hazard ratios (HR) with 95% confidence intervals (95% CI). During a mean follow-up of 8.8 years, 97 women were diagnosed with breast cancer. For both adolescence and midlife, daily consumption of rye bread was positively associated with breast cancer (HR 1.7, 95% CI 1.1-2.6 and HR 1.8, 95% CI 1.1-2.9, respectively). In contrast, persistent high consumption of oatmeal was negatively associated with breast cancer (0.4, 95% CI 0.2-0.9). No association was found for other food items or dietary patterns that included rye bread. High rye bread consumption in adolescence and midlife may increase risk of late-life breast cancer whilst persistent consumption of oatmeal may reduce the risk.

Obesity and risk of monoclonal gammopathy of undetermined significance and progression to multiple myeloma: a population-based study.

All multiple myeloma (MM) cases are preceded by the premalignant state monoclonal gammopathy of undetermined significance (MGUS). Results from previous studies show a positive association between obesity and MM; however, the association between obesity and MGUS is controversial. The aims were to determine (1) if obesity is associated with an increased risk of MGUS and light-chain MGUS (LC-MGUS) and (2) whether obesity is associated with a higher risk of progression to MM and other lymphoproliferative (LP) diseases. Data from the population-based Age, Gene/Environment Susceptibility-Reykjavik Study (N = 5764) were used. We performed serum protein electrophoresis and serum free light-chain assay on all subjects to identify MGUS and LC-MGUS cases. We included 11 different measures on current and previous obesity in our analysis. Logistic regression and Cox proportional-hazard regression were used to analyze the associations. A total of 300 (5.2%) MGUS and 275 (4.8%) LC-MGUS cases were identified. During a median follow-up of 8 years, 18 had progressed to MM and 11 to other LP diseases. We found no association between the 11 obesity markers and MGUS or LC-MGUS (odds ratios 0.81 to 1.15 for all 11 variables in both conditions). Interestingly, we found that high midlife body mass index increased risk of progression to MM and other LP diseases (hazard ratio, 2.66; 95% confidence interval, 1.17-6.05). To conclude, obesity was not associated with MGUS. However, we found overweight/obesity to be a risk factor for progression from MGUS to MM and other LP diseases, suggesting that obesity plays a role in the transformation of MGUS to MM.

Bone disease in monoclonal gammopathy of undetermined significance: results from a screened population-based study.

Previous studies have shown that individuals with monoclonal gammopathy of undetermined significance (MGUS) have an increased risk of fractures, although the underlying mechanisms remain unknown. Our aim was to analyze bone mineral density (BMD), bone volume, and risk of fractures among individuals with MGUS. We performed a screening using the Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study cohort, consisting of 5764 elderly individuals, identifying 300 individuals with MGUS, and 275 with light-chain MGUS. Quantitative computerized tomography was performed in the lumbar spine and hip to evaluate BMD and bone geometry. Analysis of variance and the Tukey honest significance test were used to compare the groups. Hospital records were used to record fractures, with a mean follow-up of 6.9 years. Cox proportional hazard was used to compare fracture risk. No difference was found in BMD between subjects with MGUS and others in the spine (P = .34) or in total hip (P = .30). Individuals with MGUS had a significant increase in bone volume compared with others in the spine (P < .001) and total hip (P < .001). Overall, the risk of fractures was not significantly increased in individuals with MGUS (hazard ratio [HR], 1.19; 95% confidence interval [CI], 0.94-1.50). Men with MGUS had a significantly increased fracture risk, compared with other men (HR, 1.46; 95% CI, 1.03-2.08). Our results show that although individuals with MGUS do not have decreased BMD, bone volume is increased, and MGUS men have a 50% increased fracture risk. These results indicate that bone disease and fractures in MGUS differ from processes known from osteoporosis.