Incomplete pregnancy is not associated with breast cancer risk: the California Teachers Study

The relationship between Mediterranean-DASH diet intervention for the neurodegenerative delay (MIND) Diet and risk of breast Cancer: a case-control study among iranian adult women

BACKGROUND

choosing a healthier lifestyle and modifying dietary habits could prevent four million new people from developing cancer. Recently, a new index called the Mediterranean-dietary approach to stop hypertension (DASH) diet intervention for the neurodegenerative delay (MIND) diet has been developed. In the current study, we aimed to assess the relationship between the MIND diet and the risk of breast cancer (BC) among Tehranian adult women.

METHOD

In this hospital-based, case-control study, 134 Tehranian women ≥ 30 years old with recently (< 6 months) diagnosed BC, confirmed histologically and 272 women of the same age as control were included. Dietary intakes were assessed in a personal interview using a valid and reliable semi-quantitative 168-item food frequency questionnaire. The odds ratio (OR) and 95% confidence intervals (CI) of breast cancer across tertiles of the MIND diet were determined using multivariable-adjusted logistic regression analysis.

RESULTS

In the crude model, participants in the highest tertiles had lower odds of BC [(OR = 0.57; 95% CI,0.34-0.95), P for trend = 0.020)] than those with the lowest scores on the MIND diet. After controlling for potential confounding variables, individuals in the highest tertile of the MIND diet had a 45% lower risk of BC [(OR = 0.55; 95% CI, 0.32-0.96), P for trend = 0.021)] compared with those in the lowest tertile. Also, in women with an abortion history, higher adherence to the MIND diet was associated with a lower risk of BC [(OR = 0.15; 95% CI, 0.04-0.52, P for trend = 0.002)].

CONCLUSION

Our findings revealed that higher adherence to the MIND diet was associated with decreased BC risk, which was strongly observed among women with a history of abortion.

Menstrual and Reproductive Factors and Risk of Breast Cancer in Iranian Female Population: A Systematic Review and Meta-Analysis

BACKGROUND

Breast cancer (BC) is the most frequent cancer in Iranian females. Due to the changes in lifestyle and reproductive risk factors, the BC incidence rate has been rapidly increasing. Knowing risk factors of BC could significantly contribute to improve preventive behaviors. To investigate the relationship between menstrual and reproductive factors and BC in Iranian female population.

METHODS

Web of Science, PubMed, Scopus, and SID as well as references of included studies were searched. Among relevant published observational studies, 27 studies met the inclusion criteria. Pooled risk estimates for the risk factors were determined using random-effects models due to the presence of substantial heterogeneity (P < 0.05).

RESULTS

All of the selected studies had case-control design. There was a positive relationship between maternal age at first pregnancy and risk of BC (OR = 1.79 95% CI: 1.36-2.35). Also, menopausal status was associated with higher risk of BC (OR = 1.60 95% CI: 1.18-2.17), whereas, there was no association between menarche age and increased risk of BC (OR = 0.55 95% CI: 0.29-1.03). History of abortion (OR = 1.21 95% CI: 0.97-1.5), nulliparity (OR = 1.43 95% CI: 0.89-2.31), and breastfeeding history (OR = 0.68 95% CI: 0.42-1.09) were not associated with BC risk.

CONCLUSIONS

Our findings suggest that age at the first pregnancy and menopausal status were significantly associated with BC risk among Iranian women, whereas menarche age, nulliparity, and history of breastfeeding were not. In regard to the history of abortion, our findings revealed no association with BC, but in high-quality studies, this relationship was significant.

Reproductive Pattern of Parous Women and the Risk of Cancer in Later Life

We assessed the risk of any and site-specific cancers in a case-control study of parous women living in northeast Scotland in relation to: total number of pregnancies, cumulative time pregnant, age at first delivery and interpregnancy interval. We analysed 6430 women with cancer and 6430 age-matched controls. After adjustment for confounders, women with increasing number of pregnancies had similar odds of cancer diagnosis as women with only one pregnancy. The adjusted odds of cancer diagnosis were no higher in women with cumulative pregnancy time 50-150 weeks compared to those pregnant ≤ 50 weeks. Compared with women who had their first delivery at or before 20 years of age, the adjusted odds ratio (AOR) among those aged 21-25 years was 0.81, 95% CI 0.74, 0.88; 26-30 years AOR 0.77, 95% CI 0.69, 0.86; >30 years AOR 0.63, 95% CI 0.55, 0.73. After adjustment, the odds of having any cancer were higher in women who had an inter-pregnancy interval >3 years compared to those with no subsequent pregnancy (AOR 1.17, 95% CI 1.05, 1.30). Older age at first pregnancy was associated with increased risk of breast and gastrointestinal cancer, and reduced risk of invasive cervical, carcinoma in situ of the cervix and respiratory cancer.

No association between abortion and risk of breast cancer among nulliparous women: Evidence from a meta-analysis

BACKGROUND

Various epidemiological studies have demonstrated the association between abortion and risk of breast cancer among nulliparous women; however, results remain inconclusive. This meta-analysis assessed the association based on previous studies.

METHODS

PubMed, EMBase, China National Knowledge Infrastructure, Chongqing VIP, and Wanfang databases were searched for relevant articles until February 2018. In this meta-analysis, fixed-effects models were used to estimate the combined effect size and the corresponding 95% confidence interval (CI). All statistical data were analyzed using STATA 12.0.

RESULTS

A total of 14 articles consisting of 6 cohort studies and 8 case-control studies were included in this review. All articles were of high quality, as determined based on the Newcastle Ottawa Scale assessment. The combined risk ratio (RR) indicated no significant association between abortion and breast cancer among nulliparous women (RR = 1.023, 95%CI = 0.938-1.117; Z = 0.51, P = .607). Subgroup analyses revealed no significant associations between risk of breast cancer and induced abortion or between risk of breast cancer and spontaneous abortion (SA) among nulliparous women (RR = 1.008, 95% CI = 0.909-1.118 and RR = 1.062, 95%CI = 0.902-1.250, respectively). Neither 1 nor >2 abortions increased the risk of breast cancer among nulliparous women. Sensitivity analysis showed that our results were reliable and stable.

CONCLUSION

Current evidence based on epidemiological studies showed no association between abortion and risk of breast cancer among nulliparous women.

Abortion and Breast Cancer: Case-Control Study

Aims and background

The aim of the present study was to examine if certain aspects of a woman's experience of abortion might be associated with the risk of breast cancer.

Methods and study design

The case-control study was conducted in Kragujevac (Serbia) during the period 2004–2005. The case group (191 women) consisted of patients with newly diagnosed first primary breast cancer, which was histologically confirmed. The control group (191 women), individually matched by age (± 2 years), hospital admittance and place of residence (rural/urban) to the respective cases, was selected from female patients admitted for other diseases. The analysis was restricted to parous women (168 cases and 171 controls).

Results

Breast cancer risk was reduced among women who had a history of any abortion (adjusted OR, 0.46; 95% CI, 0.24–0.88). The protective effect was found for both induced abortion (adjusted OR, 0.47; 95% CI, 0.25–0.90) and spontaneous abortion (adjusted OR, 0.31; 95% CI, 0.10–0.98). It seems that these associations did not depend on the number of abortions, age at first abortion, or gestational age at first aborted pregnancy.

Conclusions

Our study suggests that even short pregnancies ending in abortion add to the protection against breast cancer.

Induced abortion and breast cancer: An updated meta-analysis

Different epidemiological studies have indicated conflicting information about the association of induced abortion (IA) with breast cancer risk. A recent meta-analysis with prospective evidences did not support the positive association between IA and breast cancer risk. Thus, we in our meta-analysis study have tried to analyze this specific association.We searched all relevant articles from an English-language literature using Pubmed, Embase, and Cochrane databases, until December 10, 2016. All the statistical analyses were performed on case-control studies, using Review Manager Software 5.3 (Cochrane Collaboration, Oxford, UK).Our meta-analysis results based on 25 studies, including 5 studies with Chinese patients, indicated that there was no association of IA with breast cancer (OR = 1.08, 95% CI 0.98-1.19, P = .1). However, significant heterogeneity was observed, and thus further subgroup analyses were conducted. The combined OR of subjects with only 1-time IA was 1.03, 95% CI 0.90 to 1.18, P = .63, while for subjects with 2 or more IAs, it was 1.06, 95% CI 0.86 to 1.30, P = .58. In addition, the ORs of subjects, with 1st IA age either less than 30 or older than 30, were 1.05, 95% CI 0.88 to 1.26, P = .59, and 1.18, 95% CI 0.93 to 1.49, P = .17, respectively. These observations indicated that number of IAs and the age of 1st IA were not associated with breast cancer risk. Due to lack of dose-response relationships, it is difficult to say if number of IAs contributed into statistical heterogeneity. But after subgroup analysis, the age at the 1st IA appeared to impact the statistical heterogeneity. The different reproductive history appears to account for the high heterogeneity among individual studies. Also analysis of nulliparous women showed no significant difference in the association of IA and breast cancer (OR = 1.02, 95% CI 0.86-1.21, P = .85). However, parous women had higher IA rate in case group than control group (OR = 1.11, 95% CI 1.02-1.20, P = .01). Ethnicities might also result in high heterogeneity; thus, we conducted subgroup analyses on Chinese subjects, importantly, with 5 studies having Chinese patients, and did not observe any difference in the incidence of IA and its association with breast cancer between case and control groups (OR = 1.05, 95% CI 0.97-1.13, P = .21).After subgroup analysis, our study showed that IA might increase the risk of breast cancer in parous women, but in the nulliparous, IA was not significantly associated with an increased risk of breast cancer.

Breast Cancer Status in Iran: Statistical Analysis of 3010 Cases between 1998 and 2014

Background

Breast cancer is the 5th leading cause of cancer death in Iranian women. This study analyzed 3010 women with breast cancer that had been referred to a cancer research center in Tehran between 1998 and 2014.

Methods

In this retrospective study, we analyzed 3010 breast cancer cases with 32 clinical and paraclinical attributes. We checked the data quality rigorously and removed any invalid values or records. The method was data mining (problem definition, data preparation, data exploration, modeling, evaluation, and deployment). However, only the descriptive analyses' results of the variables are presented in this article. To our knowledge, this is the most comprehensive study on breast cancer status in Iran.

Results

A typical Iranian breast cancer patient has been a 40–50-year-old married woman with two children, who has a high school diploma and no history of abortion, smoking, or diabetes. Most patients were estrogen and progesterone receptor positive, human epidermal growth factor (HER) negative, and P53 negative. Most cases were detected in stage 2 with intermediate grade.

Conclusion

This study revealed original findings which can be used in national policymaking to find the best early detection method and improve the care quality and breast cancer prevention in Iran.

Meanings of abortion in context: accounts of abortion in the lives of women diagnosed with breast cancer

BACKGROUND

A breast cancer diagnosis and an abortion can each be pivotal moments in a woman's life. Research on abortion and breast cancer deals predominantly with women diagnosed during pregnancy who might be advised to have an abortion. The other-discredited but persistent-association is that abortions cause breast cancer. The aim here was to understand some of the ways in which women themselves might experience the convergence of abortion and breast cancer.

METHODS

Among 50 women recruited from the Australian Breast Cancer Family Study and interviewed in depth about what it meant to have a breast cancer diagnosis before the age of 41, five spontaneously told of having or contemplating an abortion. The transcripts of these five women were analysed to identify what abortion meant in the context of breast cancer, studying each woman's account as an individual "case" and interpreting it within narrative theory.

RESULTS

It was evident that each woman understood abortion as playing a different role in her life. One reported an abortion that she did not link to her cancer, the second was relieved not to have to abort a mid-treatment pregnancy, the third represented abortion as saving her life by making her cancer identifiable, the fourth grieved an abortion that had enabled her to begin chemotherapy, and the fifth believed that her cancer was caused by an earlier abortion.

CONCLUSIONS

The women's accounts illustrate the different meanings of abortion in women's lives, with concomitant need for diverse support, advice, and information.

Reproductive risk factors associated with breast cancer in women in Bangui: a case-control study

Background

Breast cancer (breast Ca) is recognised as a major public health problem in the world. Data on reproductive factors associated with breast Ca in the Central African Republic (CAR) is very limited. This study aimed to identify reproductive variables as risk factors for breast Ca in CAR women.

Methods

A case–control study was conducted among 174 cases of breast Ca confirmed at the Pathology Unit of the National Laboratory in Bangui between 2003 and 2015 and 348 age-matched controls. Data collection tools included a questionnaire, interviews and a review of medical records of patients. Data were analysed using SPSS software version 20. Odd ratios and 95% confidence intervals (CI) for the likelihood of developing breast Ca were obtained using unconditional logistic regression.

Results

In total, 522 women with a mean age of 45.8 (SD = 13.4) years were enrolled. Women with breast Ca were more likely to have attained little or no education (AOR = 11.23, CI: 4.65–27.14 and AOR = 2.40, CI: 1.15–4.99), to be married (AOR = 2.09, CI: 1.18–3.71), to have had an abortion (AOR = 5.41, CI: 3.47–8.44), and to be nulliparous (AOR = 1.98, CI: 1.12–3.49). Decreased odds of breast Ca were associated with being employed (AOR = 0.32, CI: 0.19–0.56), living in urban areas (AOR = 0.16, CI: 0.07–0.37), late menarche (AOR = 0.18, CI: 0.07–0.44), regular menstrual cycles (AOR = 0.44, CI: 0.23–0.81), term pregnancy (AOR = 0.26, CI: 0.13–0.50) and hormonal contraceptive use (AOR = 0.62, CI: 0.41–0.93).

Conclusion

Breast Ca risk factors in CAR did not appear to be significantly different from that observed in other populations. This study highlighted the risk factors of breast Ca in women living in Bangui to inform appropriate control measures.

Understanding rural-urban differences in risk factors for breast cancer in an Indian population

PURPOSE

Although cancer registry data indicate that there are large differences in breast cancer (BC) rates between rural and urban regions of India, the reasons for these differences are not well understood.

METHODS

We conducted a hospital based case-control study (1,637 breast cancer cases; 1,515 visitor controls) in Mumbai, India, during the years 2009-2013. Extensive questionnaire data, anthropometry measurement and blood samples were collected on all participants. Using logistic regression models, we estimated risk based on odds ratio (OR) and 95 % confidence intervals (CI) for various reproductive and anthropometric measures, stratified by rural-urban status depending upon residence in first 20 years of life.

RESULTS

Waist-to-hip ratio of ≥0.95 compared to ratio ≤0.84 was strongly associated with risk of BC in both rural and urban populations (ORurban = 4.10, 95 % CI 3.03-5.56; ORrural = 3.01, 95 % CI 1.85-4.90). First full-term pregnancy after the age of 25 compared to first full-term pregnancy below 20 years of age was associated with risk of BC in both urban and rural women (ORurban = 1.78, 95 % CI 1.32-2.41; ORrural = 2.24, 95 % CI 1.13-4.43). The prevalence of age at first full-term pregnancy was significantly lower in rural (mean age at first full-term pregnancy = 19.39 years) versus urban women (mean age at first full-term pregnancy = 22.62 years), whereas mean waist circumference was much higher in urban women (82.13 cm) compared to rural women (79.26 cm). We did not observe any association between breast feeding and risk of BC.

CONCLUSIONS

Differences in the prevalence of central adiposity and age at first full-term pregnancy between rural and urban women from India may explain some differences in breast cancer rates between these two populations.

Induced abortion and breast cancer: results from a population-based case control study in China

AIM

To determine whether induced abortion (IA) increases breast cancer (BC) risk.

MATERIALS AND METHODS

A population-based case-control study was performed from Dec, 2000 to November, 2004 in Shanghai, China, where IA could be verified through the family planning network and client medical records. Structured questionnaires were completed by 1,517 cases with primary invasive epithelial breast cancer and 1,573 controls frequency- matched to cases for age group. The information was supplemented and verified by the family planning records. Statistical analysis was conducted with SAS 9.0.

RESULTS

After adjusting for potential confounders, induced abortions were not found to be associated with breast cancer with OR=0.94 (95%CI= 0.79-1.11). Compared to parous women without induced abortion, parous women with 3 or more times induced abortion (OR=0.66, 95%CI=0.46 to 0.95) and women with 3 or more times induced abortion after the first live birth (OR=0.66, 95%CI =0.45 to 0.97) showed a lower risk of breast cancer, after adjustment for age, level of education, annual income per capita, age at menarche, menopause, parity times, spontaneous abortion, age at first live birth, breast-feeding, oral contraceptives, hormones drug, breast disease, BMI, drinking alcohol, drinking tea, taking vitamin/calcium tablet, physical activity, vocation, history of breast cancer, eating the bean.

CONCLUSIONS

The results suggest that a history of induced abortions may not increase the risk of breast cancer.

Pregnancy-related factors and the risk of breast carcinoma in situ and invasive breast cancer among postmenopausal women in the California Teachers Study cohort

Introduction

Although pregnancy-related factors such as nulliparity and late age at first full-term pregnancy are well-established risk factors for invasive breast cancer, the roles of these factors in the natural history of breast cancer development remain unclear.

Methods

Among 52,464 postmenopausal women participating in the California Teachers Study (CTS), 624 were diagnosed with breast carcinoma in situ (CIS) and 2,828 with invasive breast cancer between 1995 and 2007. Multivariable Cox proportional hazards regression methods were used to estimate relative risks associated with parity, age at first full-term pregnancy, breastfeeding, nausea or vomiting during pregnancy, and preeclampsia.

Results

Compared with never-pregnant women, an increasing number of full-term pregnancies was associated with greater risk reduction for both breast CIS and invasive breast cancer (both P trend < 0.01). Women having four or more full-term pregnancies had a 31% lower breast CIS risk (RR = 0.69, 95% CI = 0.51 to 0.93) and 18% lower invasive breast cancer risk (RR = 0.82, 95% CI = 0.72 to 0.94). Parous women whose first full-term pregnancy occurred at age 35 years or later had a 118% greater risk for breast CIS (RR = 2.18, 95% CI = 1.36 to 3.49) and 27% greater risk for invasive breast cancer (RR = 1.27, 95% CI = 0.99 to 1.65) than those whose first full-term pregnancy occurred before age 21 years. Furthermore, parity was negatively associated with the risk of estrogen receptor-positive (ER+) or ER+/progesterone receptor-positive (PR+) while age at first full-term pregnancy was positively associated with the risk of ER+ or ER+/PR+ invasive breast cancer. Neither of these factors was statistically significantly associated with the risk of ER-negative (ER-) or ER-/PR- invasive breast cancer, tests for heterogeneity between subtypes did not reach statistical significance. No clear associations were detected for other pregnancy-related factors.

Conclusions

These results provide some epidemiologic evidence that parity and age at first full-term pregnancy are involved in the development of breast cancer among postmenopausal women. The role of these factors in risk of in situ versus invasive, and hormone receptor-positive versus -negative breast cancer merits further exploration.