Breastfeeding and thyroid cancer risk in women: A dose-response meta-analysis of epidemiological studies

No such thing as a free lunch: The direct marginal costs of breastfeeding

Understanding costs associated with breastfeeding is critical to developing maximally effective policy to support breastfeeding by addressing financial barriers. Breastfeeding is not without cost; direct costs include those of equipment, modified nutritional intake, and time (opportunity cost). Breastfeeding need not require more equipment than formula feeding, though maternal equipment use varies by maternal preference. Meeting increased nutritional demands requires increased spending on food and potentially dietary supplementation, the marginal cost of which depends on a mother's baseline diet. The opportunity cost of the three to four hours per day breastfeeding demands may be prohibitively high, particularly to low-income workers. These costs are relatively highest for low-income individuals, a group disproportionately comprising racial and ethnic minorities, and who demonstrate lower rates of breastfeeding than their white and higher-income peers. Acknowledging and addressing these costs and their regressive nature represents a critical component of effective breastfeeding policy and promotion.

Technical Report: Breastfeeding and the Use of Human Milk

Breastfeeding and human milk are the normative standards for infant feeding and nutrition. The short- and long-term medical and neurodevelopmental advantages of breastfeeding make breastfeeding or the provision of human milk a public health imperative. The American Academy of Pediatrics (AAP) recommends exclusive breastfeeding for approximately 6 months after birth. Furthermore, the AAP supports continued breastfeeding, along with appropriate complementary foods introduced at about 6 months, as long as mutually desired by mother and child for 2 years or beyond. These recommendations are consistent with those of the World Health Organization (WHO). Medical contraindications to breastfeeding are rare. The AAP recommends that birth hospitals or centers implement maternity care practices shown to improve breastfeeding initiation, duration, and exclusivity. The Centers for Disease Control and Prevention and The Joint Commission monitor breastfeeding practices in United States hospitals. Pediatricians play a critical role in hospitals, their practices, and communities as advocates of breastfeeding and, thus, need to be trained about the benefits of breastfeeding for mothers and children and in managing breastfeeding. Efforts to improve breastfeeding rates must acknowledge existing disparities and the impact of racism in promoting equity in breastfeeding education, support, and services.

Policy Statement: Breastfeeding and the Use of Human Milk

Breastfeeding and human milk are the normative standards for infant feeding and nutrition. The short- and long-term medical and neurodevelopmental advantages of breastfeeding make breastfeeding, or the provision of human milk, a public health imperative. The American Academy of Pediatrics (AAP) recommends exclusive breastfeeding for approximately 6 months after birth. Furthermore, the AAP supports continued breastfeeding, along with appropriate complementary foods introduced at about 6 months, as long as mutually desired by mother and child for 2 years or beyond. These recommendations are consistent with those of the World Health Organization (WHO). Medical contraindications to breastfeeding are rare. The AAP recommends that birth hospitals or centers implement maternity care practices shown to improve breastfeeding initiation, duration, and exclusivity. The Centers for Disease Control and Prevention (CDC) and The Joint Commission monitor breastfeeding practices in US hospitals. Pediatricians play a critical role in hospitals, their practices, and communities as advocates of breastfeeding and, thus, need to be trained about the benefits of breastfeeding for mothers and children and in managing breastfeeding.

Association between breastfeeding and breast, thyroid, and cervical cancer among Korean adult women: based on the Korean Genome and Epidemiology Study

Purpose

The purpose of this study was to explore the association between breastfeeding and the prevalence of breast, thyroid, and cervical cancer among Korean adult women.

Methods

The study was a secondary analysis of data from the Korea Genome and Epidemiology Study. The final samples were 113,944 Korean women among 173,205 urban-based cohort participants collected between 2004 and 2013 for adults aged forty and over. To determine the association between female cancers and breastfeeding experience, the number of childbirth, and total breastfeeding duration, logistic regression analysis was done. The demographic characteristics, health behavior, and female history were adjusted.

Results

The prevalence of breast cancer was 1.37 times higher in the non-breastfeeding group than in the breastfeeding group. Compared to having breastfed for more than 36 months, the prevalence of thyroid cancer was 1.68 times higher at breastfeeding for 13 to 36 months, 1.67 times higher at breastfeeding for 6 to 12 months, and 2.06 times higher at breastfeeding less than 6 months. Also, the prevalence of cervical cancer was 1.54 times higher at breastfeeding for 13 to 36 months, compared to breastfeeding for more than 36 months.

Conclusion

This study found that breastfeeding experience and a longer breastfeeding duration are associated with reduced risk of breast, thyroid, and cervical cancer in Korean women. It can be used as a basis for encouraging breastfeeding, and suggests further research on modifiable factors that reduce cancer risks.

Reproductive and menstrual factors for papillary thyroid cancer risk: A case-control study in Chinese women

BACKGROUND

Thyroid cancer (TC) is threefold more common in women than men. Reproductive and menstrual factors may be related to the onset of papillary thyroid cancer (PTC). This study aims to determine the association of reproductive and menstrual factors with PTC in Chinese females.

METHODS

A total of 335 histologically confirmed cases of PTC were recruited in this case-control study. The controls were matched for age with a deviation of ± 2 years, which conducted from September 2016 to February 2019. Logistic regression models were applied to identify the association of reproductive and menstrual factors with PTC.

RESULTS

After adjustment by some variables, early menarche age (OR ≤ 13 years vs. > 13years = 2.40, 95 % CI 1.12-5.13) and shorter lifetime breastfeeding (OR <6 months vs. ≥ 6 months = 1.99, 95 % CI 1.11-3.55) significantly increased the risk of PTC, whereas younger age at first pregnancy had a protective effect against PTC (OR ≤ 24years vs. > 24 years = 0.66, 95 % CI 0.44-0.98). There was a positive correlation between premenopausal and PTC in the lower age group (OR _{premenopausal vs. Menopause by natural} =2.34, 95 %CI 1.03-5.28).

CONCLUSIONS

Early menarche age, abortion, shorter breastfeeding duration and premenopausal may be related to the occurrence of PTC. Early age at first pregnancy and larger number of full-time pregnancies were possible to decrease the risk of PTC.

Latent trajectories of infant breast milk consumption in the United States

Patterns of breastfeeding over time are not currently well understood. Limited qualitative and quantitative evidence suggests that there may be latent subgroups of mothers in the United States following very different trajectories of breast milk provision for their infants. This study used a quantitative modelling method (group-based trajectory modelling) to identify and describe these subgroups. Using data from the Infant Feeding Practices Study II (n = 3,023), the authors identified four distinct trajectories of breastfeeding intensity, each of which included a substantial subset of the total sample. A model with four groups fit the data well by objective and conceptual standards. Bivariate associations were analysed, and significant difference between trajectory group membership was found on an array of maternal and family determinants, including maternal demographics, hospital experience, and psychosocial resources, as well as on postweaning perceptions. These associations were used to create group profiles for each subgroup. Controlling for sociodemographic covariates, we also found that trajectory membership was significantly associated with several health outcomes for the target child 6 years later, including certain infections, picky eating, and health care utilization; trajectory group membership was also associated with maternal breastfeeding of subsequent children and maternal body mass index (BMI) at Year 6. Child BMI z-score and maternal breast cancer diagnosis were not significantly different across trajectory groups after accounting for confounding covariates, nor was time missed from school for the target child. Though exploratory, the initial identification and description of these four subgroups suggest future directions using breastfeeding trajectory methods, with potential implications for measurement, intervention development, and targeting.

Thyroid Cancer Epidemiology in South Spain: a population-based time trend study

PURPOSE

Thyroid cancer (TC) is the most common malignant disease of the endocrine system. The aim of this study was to analyze incidence and mortality trends of TC (C73 according to ICD-O-3) in Granada (Southern Spain) during the period 1985-2013, by sex, age, and histological type.

METHODS

This is a population-based cross-sectional study. Incidence data were obtained from the population-based Cancer Registry of Granada. All newly diagnosed cases of thyroid cancer over the period 1985-2013 were included. Joinpoint regression analysis with age-standardized rates were used to estimate annual percentage change (APC), CI 95% and turning points in trends. Results are presented by sex, age group, and histological type.

RESULTS

During the study period there were 1265 diagnosed cases of TC in Granada (72.6% in women). Incidence trends significantly increased in both men (APC: + 5.4%) and women (APC: + 4.7%). The most common histological types in both sexes were papillary (74.8%) and follicular (16.8%). The incidence has increased during the study period mainly due to papillary carcinoma, which has increased annually around 6% in both sexes. TC mortality trend during this period decreased in men (APC: -0.3%) and women (APC: -2.3%).

CONCLUSION

Our data showed an increasing trend in incidence of thyroid cancer in Granada, especially in women between 55-64 years. Mortality showed a slight decrease trend during the study period in both sexes. Papillary carcinoma was the most common histological type, with an increase of the relative weight of papillary microcarcinomas. Our study is in accordance with the European and worldwide trends in thyroid cancer incidence and mortality and sex differences.

Use of acetaminophen and risk of endometrial cancer: evidence from observational studies

Previous meta-analyses suggested that aspirin was associated with reduced risk of endometrial cancer. However, there has been no study comprehensively summarize the evidence of acetaminophen use and risk of endometrial cancer from observational studies. We systematically searched electronic databases (PubMed , EMBASE, Web of Science, and Cochrane Library) for relevant cohort or case-control studies up to February 28, 2017. Two independent authors performed the eligibility evaluation and data extraction. All differences were resolved by discussion. A random-effects model was applied to estimate summary relative risks (RRs) with 95% CIs. All statistical tests were two-sided. Seven observational studies including four prospective cohort studies and three case-control studies with 3874 endometrial cancer cases were included for final analysis. Compared with never use acetaminophen, ever use this drug was not associated with risk of endometrial cancer (summarized RR = 1.02; 95% CI: 0.93-1.13, I2 = 0%). Similar null association was also observed when compared the highest category of frequency/duration with never use acetaminophen (summarized RR = 0.88; 95% CI: 0.70-1.11, I2 = 15.2%). Additionally, the finding was robust in the subgroup analyses stratified by study characteristics and adjustment for potential confounders and risk factors. There was no evidence of publication bias by a visual inspection of a funnel plot and formal statistical tests. In summary, the present meta-analysis reveals no association between acetaminophen use and risk of endometrial cancer. More large scale prospective cohort studies are warranted to confirm our findings and carry out the dose-response analysis of aforementioned association.