Abstract P6-10-07: Differences in genome-wide DNA methylation levels in breast milk by race and lactation duration

Introduction: Identifying biomarkers of breast cancer risk among young women would have value in developing effective screening and prevention strategies at early ages. We have proposed that DNA methylation analysis of breast milk may provide breast cancer risk information among young women, and could possibly provide etiologic clues related to the higher rates of early onset cancers among African American as compared with White women in the US.

Objective: The purpose of this project was to identify associations between genome-wide DNA methylation levels in breast milk and race adjusted for other breast cancer risk factors.

Study Population: Cancer-free, lactating U.S. Black (n=57) and White (n=82) women, ages 19 to 44, provided frozen breast milk samples, as well as demographic, behavioral, and reproductive data, to the Breastmilk Laboratory at University of Massachusetts Amherst. Women were uniparous and did not have a personal history of breast cancer at the time of milk donation.

Methods: DNA was extracted from breast milk samples using the phenol-chloroform method. Genome-wide methylation analysis was performed on breast milk samples using the Infinium HumanMethylation450 BeadChip. Probes with 50% or more missing data, cross-reactive probes, as well as probes with minor allelic frequency greater than 0.05 in European- or African-Americans were removed, leaving 379,042 CpG sites for analysis. Multivariate generalized linear regression models were used to examine associations between race and other breast cancer risk factors and methylation beta values, adjusting for potential confounding factors. P-values less than 1E-7 were considered statistically significant.

Results: Black women in this study were more likely to be never smokers, to not have used over-the-counter pain medication in the past week, and to breastfeed longer. After adjustment by age, BMI, smoking status, and batch number, race was significantly associated with differential methylation at 1143 CpG sites, including 1024 at which Black women demonstrated increased methylation levels. Additionally, breastfeeding duration was associated with 269 CpG sites, with 268 showing a significant inverse relationship with methylation. Methylation sites significantly associated with Black race and lactation duration were located within tumor suppressor and promoter genes as well as in genes implicated in obesity and diabetes.

Conclusion: This preliminarily analysis of DNA methylation in breast milk suggests that Black women have increased methylation and longer breastfeeding is associated with reduced methylation. Further research to understand how etiologic factors related to breast cancer may alter DNA methylation patterns in normal breast may lead to improved understanding of breast cancer risk at a young age and potentially causes of racial disparities in breast cancer incidence between White and Black women.

Citation Format: Davis Lynn BC, Bodelon C, Pfeiffer RM, Yang HP, Yang H, Lee M, Laird PW, Campan M, Weisenberger DJ, Murphy J, Sherman ME, Browne EP, Anderton DL, Arcaro KF, Gierach GL. Differences in genome-wide DNA methylation levels in breast milk by race and lactation duration [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-10-07.

Enteral feeding in patients with major burn injury: the use of nasojejunal feeding after the failure of nasogastric feeding

Patients with major burn injury have increased protein and energy requirements and early feeding is an established part of their management. The optimal method of feeding is unknown. Nasogastric feeding is often unsuccessful and total parenteral nutrition has a number of potential disadvantages. Post pyloric feeding is an alternative means of providing enteral nutrition. We report our experience of enteral feeding of patients with significant burn injury. Nasogastric feeding was successful in only 7 of 17 patients (41%). The commonest reason that nasogastric feeding failed was gastric stasis. All patients who failed nasogastric feeding were commenced on nasojejunal feeding and a further two patients were fed by this route initially. Ten of these 12 patients (83%) were successfully fed nasojejunally. No major adverse events attributable to nasojejunal feeding were identified, a nasojejunal tube was successfully placed in all but 1 patient and the tubes were well tolerated. We conclude that nasojejunal tube feeding should be considered in all patients with significant burn injury who cannot tolerate nasogastric tube feeding.

Naso-jejunal feeding in allogeneic bone marrow transplant recipients: results of a pilot study

Patients undergoing allogeneic bone marrow transplants (BMT) are often malnourished prior to commencing the procedure. They face intensive treatment with often marked nutritional consequences. There is no consensus on the optimal nutritional management of these patients. Elective parenteral nutrition (PN), beginning pre-transplant irrespective of the patients nutritional status, or the use of "salvage" PN, beginning during the post-transplant period if the patient fails to maintain nutritional status with oral diet, have been used. Enteral nutrition may benefit the patient by maintaining nutritional support throughout the transplant period, avoiding the complications and expense of PN and possibly, by using specific diets, protecting the gastrointestinal tract from the effects of chemoradiation. However, naso-gastric feeding during a transplant is not without risks, including the safe insertion of a tube in patients with mucositis and pan-cytopenias, tube displacement by vomiting and aspiration from gastro-oesophageal reflux. An alternative approach is to use naso-jejunal (NJ) feeding tubes which are associated with less risk of loss due to vomiting and less risk of aspiration. We report a pilot study of 15 allogeneic BMT patients who had elective NJ feeding initiated before conditioning therapy irrespective of perceived nutritional compromise. This was well tolerated and feasible with a motivated nutritional team.

Demographics of dumping. II: A national environmental equity survey and the distribution of hazardous materials handlers

Using a national survey of facilities governed by the Resource Conservation and Recovery Act (RCRA), we examine the sociospatial distribution of a much larger group of hazardous materials handlers than did previous environmental equity studies. Overall we find that RCRA-governed facilities are more likely to be sited in working-class neighborhoods with lower percentages of minority residents. We do not find evidence of stark environmental inequities. RCRA facilities, however, are close to neighborhoods with a higher percentage of minority residents. And in nonmetropolitan areas, they are slightly more likely to be located in neighborhoods with a higher percentage of black residents.

Environmental equity in Superfund. Demographics of the discovery and prioritization of abandoned toxic sites

This article presents findings of the first national tract-level analysis of the distribution of residential characteristics, including the percentage of selected minorities and socioeconomically disadvantaged groups, in relation to uncontrolled toxic waste sites (i.e., CERCLIS and NPL sites). In contrast to prevailing notions, the authors find that uncontrolled toxic waste sites are not disproportionately located in minority neighborhoods or neighborhoods of socioeconomically disadvantaged residents. However, multivariate analyses of site distribution and a hazard regression analysis of the site prioritization process suggest that communities with a higher percentage of Black residents are less likely to receive NPL (National Priorities List) designation, delaying potential remediation. Biases in the prioritization process are, however, substantively small.

Environmental equity: the demographics of dumping

Research addressing "environmental equity" and "environmental racism" claims that facilities for treatment, storage, and disposal of hazardous wastes (TSDFs) are located disproportionately in minority areas. In the first comprehensive study of TSDFs to use census tract-level data, we find no nationally consistent and statistically significant differences between the racial or ethnic composition of tracts which contain commercial TSDFs and those which do not. TSDFs are more likely to be found in tracts with Hispanic groups, primarily in regions with the greatest percentage of Hispanics. Different geographic units of analysis elaborate on, but are consistent with, these results.

Demographic seasonality and development: the effects of agricultural colonialism in Taiwan, 1906-1942

Nearly all developed countries have experienced dramatic declines in the seasonality of demographic behavior over the last century. This article examines seasonal behavior in the population of Taiwan between 1906 and 1942, during Japanese colonial rule. First, we analyze seasonal demographic cycles and their ties to the cultural calendar and agriculture. Second, we compare seasonality in two regions (Xinzhu and Tainan) that experienced different agricultural development under the colonial regime. Findings demonstrate that demographic seasonality was less pronounced when urban development and colonial agricultural intensification produced more heterogeneous seasonal patterns of labor. We find that changes in agricultural organization, rather than purely a shift to nonagricultural production, may significantly reduce established seasonal timing of demographic behavior.

Temporal dimensions of the fertility transition: an age-period-cohort analysis of frontier fertility

"This paper evaluates age, period, and cohort effects on marital fertility during onset of the Utah fertility transition (1880-1900). Computerized genealogies are used to derive age-period-cohort fertility rates for 49,842 once-married couples. Age, period and cohort effects on marital fertility are then estimated using Johnson's (1985) relational model. Declining marital fertility in Utah is shown to be explained by both lower fertility levels across periods and increasing age-specific limitation across cohorts. Direct cohort effects on fertility are insignificant. These results are consistent with prior research, and the view that fertility levels were adaptive (in part through birth spacing across ages) to immediate contexts of childbearing while age-specific fertility truncation increased across cohorts (in part through the more general diffusion of contraceptive innovations)."

Migration and fertility: behavioral change on the American frontier

This study focuses on the relationship between fertility and migration in families settling the Utah Territory. Genealogical data are used to identify the timing of migration (i.e., after, during, or before childbearing) and country of originfor migrants; and to analyze both fer tility levels for different types of migrants and the changes in fertility behavior associated with these levels. The highest fertility levels are among adults who migrated during their reproductive ages. Those who migrated young, before childbearing began, have lower fertility and are similar to natives of the frontier. Adult immigrants and emigrants of the Utah Territory use multiple strategies offamily formation.

Evidence for environmental familiality of kallikrein excretion in Utah kindreds

In investigating the role of urinary kallikrein in the pathophysiology of hypertension, we measured 12-hour kallikrein excretion in 1,100 persons in 68 Utah kindreds. The kallikrein excretion was statistically adjusted to account for variations in body size and urine output. Adjusted kallikrein excretion was greater in youths than in adults and correlated with potassium excretion and sodium excretion in persons with normal blood pressure. It was decreased in normotensive subjects with strong family histories of stroke and hypertension, but was not significantly different in adults with hypertension. Adjusted kallikrein excretion was correlated between pairs of siblings, parent-offspring pairs and spouses. Our results indicate that kallikrein excretion is a familial variable, with the familiality due more to shared environmental than genetic factors.

Birth spacing and fertility limitation: a behavioral analysis of a nineteenth century frontier population

Our analysis of changing birth interval distributions over the course of a fertility transition from natural to controlled fertility has examined three closely related propositions. First, within both natural fertility populations (identified at the aggregate level) and cohorts following the onset of fertility limitation, we hypothesized that substantial groups of women with long birth intervals across the individually specified childbearing careers could be identified. That is, even during periods when fertility behavior at the aggregate level is consistent with a natural fertility regime, birth intervals at all parities are inversely related to completed family size. Our tabular analysis enables us to conclude that birth spacing patterns are parity dependent; there is stability in CEB-parity specific mean and birth interval variance over the entire transition. Our evidence does not suggest that the early group of women limiting and spacing births was marked by infecundity. Secondly, the transition appears to be associated with an increasingly larger proportion of women shifting to the same spacing schedules associated with smaller families in earlier cohorts. Thirdly, variations in birth spacing by age of marriage indicate that changes in birth intervals over time are at least indirectly associated with age of marriage, indicating an additional compositional effect. The evidence we have presented on spacing behavior does not negate the argument that parity-dependent stopping behavior was a powerful factor in the fertility transition. Our data also provide evidence of attempts to truncate childbearing. Specifically, the smaller the completed family size, the longer the ultimate birth interval; and ultimate birth intervals increase across cohorts controlling CEB and parity. But spacing appears to represent an additional strategy of fertility limitation. Thus, it may be necessary to distinguish spacing and stopping behavior if one wishes to clarify behavioral patterns within a population (Edlefsen, 1981; Friedlander et al., 1980; Rodriguez and Hobcraft, 1980). Because fertility transition theories imply increased attempts to limit family sizes, it is important to examine differential behavior within subgroups achieving different family sizes. It is this level of analysis which we have attempted to achieve in utilizing parity-specific birth intervals controlled by children ever born.(ABSTRACT TRUNCATED AT 400 WORDS)

Historical epidemiology of smallpox in Aland, Finland: 1751-1890

We analyze a 140-year series of smallpox deaths in the Aland Islands, Finland. Vaccination, introduced in 1805, dramatically reduced the annual number of smallpox deaths. It also influenced the age distribution of smallpox deaths, changing smallpox from a childhood disease before 1805 to one which affected both adults and children after 1805. This appears to be due to the fact that Alanders were usually vaccinated only once during childhood and often lost their immunity during adulthood. Spectral analysis of the prevaccination time series of smallpox deaths demonstrates a strong seven-year periodicity, reflecting the amount of time necessary to build up a cohort of nonimmune individuals. After the introduction of vaccination, the periodicity changes to eight years. The probability that a parish in Aland was affected by a smallpox epidemic is shown to be highly correlated with migration patterns and parish population sizes.

Population estimates from longitudinal records in otherwise data-deficient settings

Existing methods for estimating population parameters in settings of data deficiency do not provide techniques for analysis of commonly available longitudinal data. In setting where complete population data is unavailable, longitudinal data recorded for only a subset of the total population are often available (e.g., event registers, genealogies). In this article we present and evaluate models which derive population parameters for the population subgroup underlying such longitudinal data. Using the distribution of individual times until first recorded event within a measurement interval, population parameters are estimated which provide basic denominator data for analyzing event occurrence. The models which we derive are especially suited to records which may include migration and population growth trends. The use of the models is demonstrated and evaluated through an application to genealogical records for a nineteenth-century population. Possible extensions of these models and their major limitations are also discussed.

A macrosimulation approach to the investigation of natural fertility

This paper is part of a long-term investigation known as the Mormon Historical Demography Project. It examines the capability of a simulation model, originally proposed by John Bongaarts (1976), to fit the natural fertility pattern which characterized the mid-nineteenth century Mormon population. Application of this model permits estimates to be made of the historical timing and age-incidence of fertility limitation. A sensitivity analysis of the model's parameters demonstrates that simple changes in the model's proximate determinants of fertility, excluding contraceptive practices, would be insufficient to account for later transition effects. Thus the results successfully capture the dynamics underlying the Mormon natural fertility pattern as well as offer a framework for future modeling of the transition away from natural fertility.