Association between reproductive factors and breast cancer in an urban set up at central India: A case-control study

Association of hormonal and reproductive risk factors with breast cancer in Indian women: A systematic review of case-control studies

The incidence of breast cancer in India has seen a rapid increase in recent years. Hormonal and reproductive risk factors for breast cancer have been affected by socioeconomic development. Studies on breast cancer risk factors in India are limited by the small sample size and specific geographical area. The current systematic review was carried out to assess the association of hormonal and reproductive risk factors with breast cancer in Indian women. A systematic review of MEDLINE, Embase, Scopus, and Cochrane database of systematic reviews were done. Relevant case-control studies published in peer-reviewed indexed journals were analyzed for hormonal risk factors such as age at menarche, menopause, and first childbirth; breastfeeding; abortion; and oral contraceptive pills use. Younger age (<13 years) at menarche was associated with high risk (odds ratio 1.23-3.72). Other hormonal risk factors with strong association were age at first childbirth and menopause, parity, and duration of breastfeeding. Abortion and the use of contraceptive pills did not have a clear association with breast cancer. Hormonal risk factors have a higher association in premenopausal disease and estrogen receptor-positive tumors. There is a strong association between hormonal and reproductive risk factors and breast cancer in Indian women. The protective effect of breastfeeding is related to the cumulative duration of breastfeeding.

Women’s breast cancer risk factors in Kinshasa, Democratic Republic of the Congo

Purpose: Breast cancer (BC) is the most common malignancy and the leading cause of cancer-related deaths among women worldwide. Risk factors for this disease are numerous and their prevalence varies according to racial and ethnic groups and geographical regions. Therefore, we sought to identify BC risk factors in the Congolese population. Methods: A case-control study was conducted at the Nganda Hospital Center in Kinshasa, Democratic Republic of the Congo. One hundred and sixty patients with breast cancer (cases) were compared to 320 women who did not have BC (controls). STATA version 16 was used to analyze data with statistical significance considered at p < 0.05. Results: There is a strong association between BC in Congolese women and early menarche age (adjusted odds ratio [aOR] = 2.3; 95% CI: 1.2-4.3), family history of BC (aOR = 2.5; 95% CI: 1.2-5.5), overweight (aOR = 1.8; 95% CI: 1.1-2.7), and obesity (aOR = 7.3; 95% CI: 4.0-13.4). Conclusion: Our results indicate the presence of certain conventional risk factors. Thus, these results will be of great value in establishing adequate evidence-based awareness and preventive measures among the Congolese population.

Reproductive factors and breast cancer risk: A meta-analysis of case-control studies in Indian women

Background/Objective:

India is the world's most biodiverse region and is undergoing a period of dramatic social and economic change. Due to population's explosion, climate change and lax implementation of environmental policies, the incidence of breast cancer is increasing. From population-based cancer registry data, breast cancer is the most common cancer in women in urban registries where it constitutes more than 30% of all cancers in females. We conducted a meta-analysis of all breast cancer case–control studies conducted in India during 1991–2018 to find pooled estimates of odds ratio (OR).

Materials and Methods:

Eligible studies were identified through a comprehensive literature search of PubMed, EMBASE, and HINARI databases from 1991 to January 2018. This analysis included 24 observational studies out of 34 that reported the case–control distribution of reproductive factors, body mass index (BMI) and type of residence. The analysis was performed using RevMan 5.3 (Review Manager, 2017) applying the random-effects model.

Results:

A total of 21,511 patients (9889 cases and 11,622 controls) were analyzed, resulting in statistically significant association between breast cancer and the following reproductive factors: never breastfeed (OR: 3.69; 95% confidence interval [CI]: 1.70, 8.01), menopausal age >50 years (OR: 2.88; 95% CI: 1.85, 3.85), menarche age <13 years (OR: 1.83; 95% CI: 1.34, 2.51), null parity (OR: 1.58; 95% CI: 1.21, 2.06), postmenopause (OR: 1.35; 95% CI: 1.13, 1.62), and age at the 1^st pregnancy >25 years (OR: 1.57; 95% CI: 1.37, 1.80). Family history (FH) of breast cancer (OR: 5.33; 95% CI: 2.89, 9.82), obesity (OR: 1.19; 95% CI: 1.00, 1.42), and urban residence (OR: 1.22; 95% CI: 1.03, 1.44) were also found to be significant risk factors.

Conclusion:

The results of this meta-analysis are indicative of significant associations between reproductive factors and breast cancer risk, profoundly so among women experiencing menopause after the age of 50, women who never breastfeed and FH of breast cancer.

Assessment of common risk factors and validation of the Gail model for breast cancer: A hospital-based study from Western India

Objective

Modified Gail Model is a noninvasive, easy to implement risk estimation tool for absolute breast cancer risk. It was developed with data collected from non African American females and further modified for African-American, the Hispanic, and Native American populations. The use of this model for population outside the US and European country is not yet validated. We evaluated the prevalent risk factors and the effectiveness of the Gail model for risk assessment in our local Indian population.

Materials and Methods

A retrospective analysis of a prospectively maintained database was conducted on patients treated between 2008 and 2013. Six hundred and fifty patients were included in each group. Six questions were taken as per the breast cancer risk assessment tool calculator. A value of over 1.67% was taken as a high risk for breast cancer development.

Results

The mean age of the participant was 50 ± 21.3 years in cases and 41 ± 16.4 years in controls. Age and age at first childbirth >30 years were found to be significant and associated with increased risk of breast carcinoma, but the age at menarche, family history, previous breast biopsy, and atypical hyperplasia was no significant. The Gail model was assessed, and sensitivity was 10.30% and 96.30% specificity for our population. Positive and negative predictive values were 73.62% and 51.77%.

Conclusion

Our study concluded that the Gail model is not an appropriate risk assessment tool for the population in its present form. For the future application of this model, we need to perform a bigger study with a higher sample size representing a maximum number of local variabilities in the Indian population.

Clinical features and first degree relative breast cancer, their correlation with histological tumor grade: a 5-year retrospective case study of breast cancer in Mizoram, India

The aim was to assess the association of histological tumor grade with other clinical features and epidemiological factors of women with invasive breast carcinoma. A retrospective study of 103 Mizo breast cancer patients visiting hospitals was made in Aizawl, Mizoram, Northeast India. With a prior consent, information on epidemiological factors and family history in relation to cancer was obtained. Clinical reports were obtained from their medical records. The frequency of distribution was calculated for age at diagnosis and tumor characteristics. Statistical analysis for different variables was done using a chi-square test. p < 0.05 was considered significant. The histological tumor grades in our studies were found to be associated with lymph node invasion (p < 0.021), different subtype of hormone receptor such as ER status (p < 0.004), ER/PR status (p < 0.007), HER2/neu status (p < 0.014), and ER/PR/HER2 status (p < 0.025). A patient with a family history of breast cancer in their 1st degree relative is also seen to have association in determining the tumor grade (p < 0.003). Reproductive history, lifestyle and dietary habits, tobacco, and alcohol consumption were found to have no influence on breast cancer tumor grade. Our results showing significant correlation between status of lymph node, ER, PR, and HER2/neu oncoprotein and family history with 1st degree relative breast cancer are the first time report to target and focus on the possible role of biomarkers for diagnosis among the Mizo tribal breast cancer patients.

Characteristics and Correlates of Woman Eligible for Targeted Screening Mammography in Oman

OBJECTIVES

We sought to determine the characteristics of women eligible for a high-yield screening mammography program in Oman.

METHODS

We conducted a retrospective review of women who underwent breast cancer screening at the Oman Cancer Association from 22 December 2009 to 6 February 2011. Women with a Breast Imaging Reporting and Data System (BI-RADS) score of 4-5 were compared with those with a score of 1-3 based on well-known breast cancer risk factors using the case-control approach analysis.

RESULTS

A BI-RADS score of 4-5 was found in 16.2% of women screened for breast cancer. A higher likelihood of a BI-RADS score of 4 or 5 was observed among women who did not breastfeed (odds ratio (OR) = 2.564; 95% confidence interval (CI): 1.690, 3.890), had their first pregnancy at an older age (OR = 1.062; 95% CI: 1.041, 1.083), used oral contraceptives (OR = 1.397; 95% CI: 1.008, 1.938), and those who reported a positive family history of malignancies (OR = 1.633; 95% CI: 1.285, 2.076). A BI-RADS score of 4 or 5 was significantly less likely in women with a higher number of full-term pregnancies (OR = 0.919; 95% CI: 0.890, 0.948). BI-RADS 4-5 were independently predicted in women with a lower number of full-term pregnancies, did not breastfeed, used oral contraceptives, and who had a positive family history of malignancies. These variables explained 84.0% of the variation in mammogram results.

CONCLUSIONS

In the absence of a national screening program for breast cancer, the high-risk approach for screening should be considered. Women with the above characteristics should be identified and motivated to seek mammogram regularly to warrant a better outcome.

Breastfeeding Mode and Risk of Breast Cancer: A Dose-Response Meta-Analysis

BACKGROUND

Breastfeeding reduces women's risk of breast cancer. Since exclusive breastfeeding has a stronger hormonal effect, it could theoretically result in a greater reduction in breast cancer risk than any breastfeeding mode. No meta-analysis has examined breast cancer risk by breastfeeding mode. Research aim: The authors conducted a meta-analysis for breast cancer risk in parous women who breastfed exclusively or in any mode versus parous women who formula fed their infants, and they estimated the summary dose-response association by the accumulated duration of any breastfeeding mode.

METHODS

A systematic review of studies published between 2005 and 2015 analyzing breastfeeding and breast cancer risk in women was conducted in PubMed and EBSCOhost. A meta-analysis ( n = 65 studies) with fixed effects (or random effects, if heterogeneity existed) was carried out stratified by breastfeeding mode and menopausal and parity status. A summary dose-response association was estimated using the generalized least-squares method.

RESULTS

The summary relative risk (SRR) for breast cancer in parous women who breastfed exclusively was 0.72, 95% confidence interval (CI) [0.58, 0.90], versus parous women who had never breastfed. For parous women who breastfed in any mode, the SRR was lower in both premenopausal women (0.86, 95% CI [0.80, 0.93]) and postmenopausal women (0.89, 95% CI [0.83, 0.95]). There was no heterogeneity or publication bias. There is weak evidence of a difference between exclusive and any breastfeeding mode ( p = .08). The summary dose-response curve was nonlinear ( p < .001).

CONCLUSION

Exclusive breastfeeding among parous women reduces the risk of breast cancer compared with parous women who do not breastfeed exclusively.

Do Breast Cancer Risk Factors Affect the Survival of Breast Cancer Patients in Southern Sri Lanka?

Background:

Breast cancer continues to be a major cause of morbidity among women in Sri Lanka. Possible effects of etiological risk factors on breast cancer specific survival (BCSS) of the disease is not clear. This study was designed to explore the impact of breast cancer risk factors on the BCSS of patients in Southern Sri Lanka.

Method:

This retro-prospective study included all breast cancer patients who had sought immunohistochemistry services at our unit from May 2006 to December 2012. A pre-tested, interviewer-administered questionnaire was used to gather information on risk factors. BCSS was estimated using the Kaplan-Meier model. Univariate Cox-regression analysis was performed with 95% confidence intervals using the SPSS statistical package.

Results:

A total of 944 breast cancer patients were included. Five year BCSS was 78.8%. There was a statistically significant difference between the patients who had a family history of breast cancer and no family history of any cancer in terms of the presence/absence of lymph node metastasis (p=0.011) and pathological stage (p=0.042). The majority of the premenopausal patients had associated DCIS (p<0.001) and large tumours (p=0.015) with positive lymph nodes (p=0.016). There was no statistically significant association between hormone receptor subtypes and hormone related risk factors. Univariate analysis revealed that breast cancer risk factors had no significant effect on the BCSS.

Conclusion:

Even though family history of breast cancer and premenopausal status are associated with poor prognostic features, they, in line with the other breast cancer risk factors, appear to have no significant effect on the BCSS of patients in Southern Sri Lanka.

Breast Cancer and Modifiable Lifestyle Factors in Argentinean Women: Addressing Missing Data in a Case-Control Study

A number of studies have evidenced the effect of modifiable lifestyle factors such as diet, breastfeeding and nutritional status on breast cancer risk. However, none have addressed the missing data problem in nutritional epidemiologic research in South America. Missing data is a frequent problem in breast cancer studies and epidemiological settings in general. Estimates of effect obtained from these studies may be biased, if no appropriate method for handling missing data is applied. We performed Multiple Imputation for missing values on covariates in a breast cancer case-control study of Córdoba (Argentina) to optimize risk estimates. Data was obtained from a breast cancer case control study from 2008 to 2015 (318 cases, 526 controls). Complete case analysis and multiple imputation using chained equations were the methods applied to estimate the effects of a Traditional dietary pattern and other recognized factors associated with breast cancer. Physical activity and socioeconomic status were imputed. Logistic regression models were performed. When complete case analysis was performed only 31% of women were considered. Although a positive association of Traditional dietary pattern and breast cancer was observed from both approaches (complete case analysis OR=1.3, 95%CI=1.0-1.7; multiple imputation OR=1.4, 95%CI=1.2-1.7), effects of other covariates, like BMI and breastfeeding, were only identified when multiple imputation was considered. A Traditional dietary pattern, BMI and breastfeeding are associated with the occurrence of breast cancer in this Argentinean population when multiple imputation is appropriately performed. Multiple Imputation is suggested in Latin America’s epidemiologic studies to optimize effect estimates in the future.

Risk of breast cancer in relation to reproductive factors in North-West of Iran, 2013-2014

More than one million new patients suffer from breast cancer annually in the world. In developed countries, breast cancer is the most common malignancy diagnosed among women, and in developing regions, it often ranks second to cervical cancer. This study aimed to investigate the relationship between incidence of breast cancer and reproductive factors in North-West of Iran. This retrospective analytical control-case study was conducted with 235 breast cancer patients and 235 women in the control group. Data collection tools included a set of questions with interviews and patient medical records. Data were analyzed using statistical tests: t-test, Chi-square, Fisher, and Pearson correlation coefficient. Significantly increased risks were associated between breast cancer and older age at first pregnancy, age at menopause and history of contraceptive use. A trend for decreasing risk were observed with increasing parity. Findings of this study showed no association between breast cancer and age at menarche. The study results suggested that physiological and reproductive factors may play important roles in the development breast cancer among Iranian women.

Risk of cancer with combined oral contraceptive use among Iranian women

Oral contraceptive use is the most common type of contraception. More than 300 million women worldwide take oral contraceptives every day. However, there is a concern about the relationship with the incidence of cancer. This analytical retrospective study aimed to investigate the relationship between the incidence of cervical and breast cancers and oral contraceptive use in 128 Iranian patients with cervical cancer, 235 with breast cancer and equal numbers of controls. Data were collected through interviews with an organized set of questions. Details were also extracted from patient files. Data were analyzed using Student's t-test, chi-square and Fisher's exact tests, and Pearson's correlation analysis. The result revealed correlations between both cervical and breast cancers and history of contraceptive pills use. While cervical cancer significantly correlated with duration of use of pills, breast cancer had significant correlations with the type of oral contraceptive and age at first use. No significant relationships were found between the two types of cancer and age at discontinuation of oral contraceptives, patterns of use, and intervals from the last use. The use of oral contraceptives may triple the incidence of cervical cancer and doubles the incidence of breast cancer. Therefore, performing Pap smears every six months and breast cancer screening are warranted for long-term oral contraceptive users.

Epidemiological correlates of breast cancer in South India

BACKGROUND

Breast cancer is the most frequent cancer in women globally and represents the second leading cause of cancer death among women (after lung cancer). India is going through epidemiologic transition. It is reported that the incidence of breast cancer is rising rapidly as a result of changes in reproductive risk factors, dietary habits and increasing life expectancy, acting in concert with genetic factors.

MATERIALS AND METHODS

In order to understand the existing epidemiological correlates of breast cancer in South India, a systematic review of evidence available on epidemiologic correlates of breast cancer addressing incidence, prevalence, and associated factors like age, reproductive factors, cultural and religious factors was performed with specific focus on screening procedures in southern India.

RESULTS

An increase in breast cancer incidence due to various modifiable risk factors was noted, especially in women over 40 years of age, with late stage of presentation, lack of awareness about screening, costs, fear and stigma associated with the disease serving as major barriers for early presentation.

CONCLUSIONS

Educational strategies should be aimed at modifying the life style, early planning of pregnancy, promoting breast feeding and physical activity. It is very important to obtain reliable data for planning policies, decision-making and setting up the priorities.