Table 1.
Main results, risk factors and study design of studies associated with breast cancer incidence in various regions of the world.
| Reference | Main Results/Findings and Risk Factors | Sample size | Study type/design |
|---|---|---|---|
| Asia | |||
| (24) | Breast cancer incidence rates were higher in Asian Indian and Pakistani Americans (AIPA) than in non-Hispanic white Americans (NHW). Family history of breast cancer, reproductive factors | 4900 AIPA and 482 250 NHW | Surveillance, Epidemiology and End Results-based study |
| (25) | Breast cancer was more common among postmenopausal women who had early menarche, late menopause, and a positive family history of breast cancer | 326 women | Cross-control study |
| (26) | Breast density was positively associated with age, body mass index (BMI), and parity, and negatively associated with smoking and oral contraceptive use | 477 women | Cross-sectional study |
| (27) | Breast cancer incidence was projected to increase over time, particularly among women aged 50 years and older. | 9771 registered diagnosed cases | Time-trend analysis |
| (28) | Metaplastic breast carcinoma was associated with worse survival outcomes compared to invasive ductal carcinoma (Histological type of cancer) | 42 patients | Retrospective closed Cohort study |
| (29) | Epstein-Barr virus (EBV), human papillomavirus (HPV), and mouse mammary tumor virus (MMTV) were detected in breast cancer tissue samples, suggesting a possible etiological role of these viruses in breast cancer | tissue biopsies (n = 250) | Case-control study |
| (30) | P53 overexpression was associated with hormone receptor status and triple-negative breast carcinoma | 91 patients | Retrospective study |
| (31) | Younger breast cancer patients (<40 years old) had more advanced cancer at diagnosis and worse survival outcomes compared to older patients (Age) | 1,334 patients | Retrospective study |
| (32) | Transforming growth factor β1 (TGFβ1) gene polymorphism (T29C) was associated with an increased risk of breast cancer | 150 subjects, 80 cases and 70 healthy controls | Case-control study |
| (33) | The prevalence of BRCA1/2 mutations was higher in Indian breast and/or ovarian cancer patients than non-BRCA mutations | 1010 patients | Multi-gene panel screening |
| (34) | Delays in diagnosis and treatment of breast cancer were associated with lack of knowledge about breast cancer symptoms and risk factors, as well as poor referral systems | 269 breast cancer patients | Mixed-methods study |
| (35) | Obesity was associated with increased oxidative stress in breast cancer patients | 30 patients women, 30 healthy control | Cross-sectional study |
| (36) | Lack of knowledge about breast cancer symptoms and risk factors was common among women in a low socio-economic area of Mumbai | 480 women | Community-based study |
| (37) | Low serum levels of 25-hydroxyvitamin D were associated with an increased risk of breast cancer in Indian women | 297 subjects | Case-control study |
| (38) | The prevalence of breast cancer screening was low among women aged 30-49 years in India, and was associated with higher education, urban residence, and wealth. | 336,777 women aged 30-49 years | Secondary data analysis |
| (39) | Air pollution emissions are associated with a higher incidence and prevalence of breast cancer in the Aktobe region of western Kazakhstan | Retrospective study | |
| (40) | Genetic polymorphisms in the DNA repair genes XRCC1 and XRCC3 may be associated with breast cancer susceptibility in Bangladeshi women | 121 breast cancer patients and 133 healthy controls | Case-control study |
| (41) | Gene-positive breast cancer in UAE had an earlier age of onset, higher rates of bilateral tumors, and lower rates of lymph node involvement compared to gene-negative tumors | 309 patients | Retrospective study |
| (42) | Sedentary lifestyle and unhealthy dietary habits were associated with an increased risk of breast cancer among women attending an oncology day treatment center in Turkey | 65 diseased women, 65 healthy women | Case control study |
| (43) | Younger age at diagnosis was associated with worse outcomes in breast cancer patients, particularly those aged 25 years or younger | 137 patients | Histopathological and clinical study |
| (44) | HER2 over-expressed breast cancer was found to be more aggressive and associated with poorer prognosis in Saudi Arabian women | 1867 patients | Retrospective study |
| (45) | Triple-negative breast cancer was the most common subtype among Saudi Arabian women and was associated with younger age at diagnosis | 270 female patients | multi-centric, Cross-sectional study |
| (46) | Breast cancer patients in Botswana presented with a more advanced stage of disease and had lower survival rates compared to patients in South Africa and the United States (Late presentation) | Botswana (n = 384, 2011-2015), South Africa (n = 475, 2016-2017), and the US (n = 361,353, 2011-2012) | Retrospective study |
| (47) | Hormone receptor-positive tumors were the most common subtype of breast cancer in Rwanda, and were more commonly diagnosed at advanced stages | 138 patients | Retrospective study |
| Africa | |||
| (48) | Inherited breast cancer is a significant issue among Nigerian women, and the BRCA1/2 mutations account for a large proportion of inherited cases | 1,136 women, 997 women without cancer | Case-control study |
| (49) | The prevalence of inherited mutations in breast cancer predisposition genes among women in Uganda and Cameroon is relatively low, with BRCA1/2 mutations being the most common | 196 cases and 185 controls | A multigene sequencing panel |
| (50) | Low vitamin D status and VDR genetic polymorphisms are associated with an increased risk of breast cancer in Ethiopian women | 392 female breast cancer patients and 193 controls | Case-control study |
| America | |||
| (51) | Hair dye and chemical straightener use are associated with an increased risk of breast cancer in black women, but not in white women | participants (n = 46,709), women ages 35–74 | Prospective cohort study |
| (52) | A healthful plant-based diet is associated with a lower risk of breast cancer, whereas an unhealthful plant-based diet is associated with a higher risk of breast cancer | 76,690 women from the Nurses’ Health Study (NHS, 1984–2016) and 93,295 women from the NHSII (1991–2017). | Prospective cohort study |
| (53) | Weight loss is associated with a reduced risk of breast cancer in postmenopausal women (Obesity) | Postmenopausal women (n = 61,335) | Observational study |
| (54) | Sugar-sweetened soda consumption is associated with an increased risk of breast cancer mortality | 927 breast cancer cases | Western New York Exposures and Breast Cancer Study |
| (55) | Smoking is associated with an increased risk of breast cancer, particularly in hormone receptor-positive tumors, in African American women | 67 313 women, 45–75 years of age | Multiethnic Cohort (MEC) study |
| (56) | Blood levels of endocrine-disrupting metals are associated with an increased risk of breast cancer in American women. | 9260 women aged ≥ 20 years | multivariate logistic regression models |
| (57) | Obesity and diabetes are independently associated with an increased incidence of breast cancer in Louisiana. | Luminal A (n=1,584), TNBC 364 Luminal B 232 and HER2 + 115 | retrospective case-control study |
| (58) | Variations in TNFα, PPARγ, and IRS-1 genes are associated with survival in breast cancer patients. | breast cancer between 1995 and 1999 | Prospective cohort study |
| (59) | Certain occupations and industries, such as healthcare and the service sector, are associated with an increased risk of breast cancer in both women and men | Women 17 865 and Men 492 | Occupational Disease Surveillance System cohort |
| (60) | Exposure to ambient air emissions of polycyclic aromatic hydrocarbons is associated with an increased incidence of breast cancer in American women | N/A | Ecological study |
| Europe | |||
| (61) | Joint tobacco smoking and alcohol intake increase cancer risk | 19,898 women | Questionnaires |
| (62) | Long-term consumption of non-fermented and fermented dairy products is not associated with breast cancer risk | 33,780 women | Population-based prospective cohort study |
| (63) | Occupational exposure to organic solvents, including ethanol, is associated with increased breast cancer risk | 38,375 breast cancer cases and 191,875 controls | population-based nested case–control study |
| (64) | Benign breast diseases are associated with age, hormonal factors, and family history of breast cancer | 61 617 women | cohort study |
| (65) | Thyroid gland diseases are associated with increased breast cancer risk | 7408 women | retrospective case–control study |
| (66) | Employment in certain industries is associated with increased breast cancer risk | 845 women | population-based case-control study |
| (67) | Adherence to healthy lifestyle behaviors is associated with reduced breast cancer risk, and this association is stronger in women without a genetic predisposition to breast cancer | 146326 women | COX proportional hazard regression model |
| (68) | Occupational heat exposure is associated with increased breast cancer risk | 1,738 breast cancer cases and 1,910 controls | Case-control study |
| (69) | Smoking is associated with increased breast cancer risk | 102,927 women | Generations Study cohort |
| Israel | |||
| (70) | Breast cancer incidence is increasing among younger women (Age) | 34,251 women | Cross-sectional study |
| (71) | Inherited predisposition to breast and ovarian cancer is observed in non-Jewish populations in Israel (Genetic factors) | 68 cases | Population study |
| (72) | Cumulative mammographic density is positively associated with age-specific incidence of breast cancer | 200 women | Cohort study |
| (73) | Passive smoking is associated with increased breast cancer risk in women with NAT2 polymorphism | 137 breast cancer patients 274 population-based controls | population-based case-control study |