Polymorphisms in the estrogen receptor alpha gene (ESR1), daily cycling estrogen and mammographic density phenotypes.

BACKGROUND: Single nucleotide polymorphisms (SNPs) involved in the estrogen pathway and SNPs in the estrogen receptor alpha gene (ESR1 6q25) have been linked to breast cancer development, and mammographic density is an established breast cancer risk factor. Whether there is an association between daily estradiol levels, SNPs in ESR1 and premenopausal mammographic density phenotypes is unknown. METHODS: We assessed estradiol in daily saliva samples throughout an entire menstrual cycle in 202 healthy premenopausal women in the Norwegian Energy Balance and Breast Cancer Aspects I study. DNA was genotyped using the Illumina Golden Gate platform. Mammograms were taken between days 7 and 12 of the menstrual cycle, and digitized mammographic density was assessed using a computer-assisted method (Madena). Multivariable regression models were used to study the association between SNPs in ESR1, premenopausal mammographic density phenotypes and daily cycling estradiol. RESULTS: We observed inverse linear associations between the minor alleles of eight measured SNPs (rs3020364, rs2474148, rs12154178, rs2347867, rs6927072, rs2982712, rs3020407, rs9322335) and percent mammographic density (p-values: 0.002-0.026), these associations were strongest in lean women (BMI, ≤23.6 kg/m2.). The odds of above-median percent mammographic density (>28.5 %) among women with major homozygous genotypes were 3-6 times higher than those of women with minor homozygous genotypes in seven SNPs. Women with rs3020364 major homozygous genotype had an OR of 6.46 for above-median percent mammographic density (OR: 6.46; 95 % Confidence Interval 1.61, 25.94) when compared to women with the minor homozygous genotype. These associations were not observed in relation to absolute mammographic density. No associations between SNPs and daily cycling estradiol were observed. However, we suggest, based on results of borderline significance (p values: 0.025-0.079) that the level of 17ß-estradiol for women with the minor genotype for rs3020364, rs24744148 and rs2982712 were lower throughout the cycle in women with low (<28.5 %) percent mammographic density and higher in women with high (>28.5 %) percent mammographic density, when compared to women with the major genotype. CONCLUSION: Our results support an association between eight selected SNPs in the ESR1 gene and percent mammographic density. The results need to be confirmed in larger studies.

Pre-diagnostic high-sensitive C-reactive protein and breast cancer risk, recurrence, and survival.

Inflammation may initiate and promote breast cancer development, and be associated with elevated circulating levels of inflammation markers. A total of eight 130 initially healthy women, participated in the population-based Tromsø study (1994-2008). Pre-diagnostic high-sensitivity C-reactive protein (hs-CRP) was assessed. During 14.6 years of follow-up, a total of 192 women developed invasive breast cancer. These cases were followed for additional 7.2 years. Detailed medical records were obtained. We observed an overall positive dose-response relationship between pre-diagnostic hs-CRP and breast cancer risk (hazard ratio (HR) = 1.06, 95 % CI 1.01-1.11). Postmenopausal women with above median levels of hs-CRP (>1.2 mg/l) had a 1.42 (95 % CI 1.01-2.00) higher breast cancer risk compared to postmenopausal women with hs-CRP below median. Postmenopausal women, who were hormone replacement therapy non-users, and were in the middle tertile (0.8-1.9 mg/l), or highest tertile of hs-CRP (>1.9 mg/l), had a 2.31 (95 % CI 1.31-4.03) and 2.08 (95 % CI 1.16-3.76) higher breast cancer risk, respectively, compared with women in the lowest tertile. For each unit increase in pre-diagnostic hs-CRP levels (mg/l), we observed an 18 % increase in disease-free interval (95 % CI 0.70-0.97), and a 22 % reduction in overall mortality (95 % CI 0.62-0.98). Our study supports a positive association between pre-diagnostic hs-CRP and breast cancer risk. In contrast, increased pre-diagnostic hs-CRP was associated with improved overall mortality, but our findings are based on a small sample size, and should be interpreted with caution.

Trends in right and left-sided colon cancer.

The increasing ratio of proximal to distal colorectal carcinomas was confirmed in this population-based study of 668 new cases diagnosed among Rochester, Minnesota residents between 1940 and 1979. The change was due to a rise in the incidence of proximal lesions (from 15.1 per 100,000 person-years in 1940-59 to 17.3 per 100,000 in 1960-79) and a simultaneous fall in the incidence of distal lesions (from 35.5 to 28.2 per 100,000 person-years). Changes in definitions or referral patterns played no role in these observations, although improved diagnostic capabilities may have had an impact on the incidence of proximal lesions. These discrepant changes in incidence strongly suggest that proximal and distal colonic cancers are different diseases or have a different pathogenesis. The changing incidence rates were not associated with consistent differences in clinical characteristics at the time of initial diagnosis.

The importance of disease-free margins in resections for Crohn's disease.

It has long been a fundamental principle of surgical therapy for Crohn's disease to remove all disease prior to doing an anastomosis. The authors recently noted with concern an article describing a series of patients demonstrating that residual involvement of anastomotic microscopic disease had no significant effect on the recurrence rate at the anastomosis. Examining their own series of 710 patients undergoing surgery for Crohn's disease, the authors found 42 patients with residual anastomotic disease. The criteria for involvement were more specific than that used in the above article and included microscopic mucosal disease. The recurrence rate within the follow-up period of eight years in patients with only microscopic involvement was 89.4 per cent. This was significantly higher than the institutional recurrence rate for Crohn's resections, previously reported, of 55 per cent at ten years. The authors feel that clear margins should be obtained in resections for Crohn's disease, if at all feasible.