Research Results
Beta Version
Use the search bar below to find studies, or apply one or more filters to narrow your results. See our list of keywords to guide your search.
Search by keyword
Select
Select
- All Risk Factors
- Air Pollution
- Alcohol
- Antimicrobials
- Artificial sweeteners
- Bisphenols
- Body Weight
- Breast Density
- Chemical Mixtures
- Chemicals in products
- Cleaning Products
- Diet
- Exercise
- Family History
- Furniture & Electronics
- Genetics
- Gut Health
- Hair Dye
- Hormones
- Inflammation
- Job
- Light at night
- Metals
- Neighborhood
- Night Shift Work
- Noise
- Non-stick Pans & Waterproof Gear
- Oral Contraceptives
- PAHs
- Parabens
- PCBs
- Personal Care Products
- Pesticides
- PFAS
- Pharmaceuticals
- Place-based
- Plastic
- Pregnancy & Breastfeeding
- Processed Food
- Puberty Age
- Race/Ethnicity
- Radiation
- Red meat
- Scented Products & Soft Plastic
- Sleeping Patterns
- Soda
- Stress
- Sugar
- Sunscreen
- Tobacco
- Vitamin D
Select
Select
Select
Select
Select the Chemical Agents
- All Chemical Agents
- 1,1,2,2-TCA
- 1,3-Butadiene
- Acrolein
- Aldrin
- Alkylphenols
- Antimicrobials
- Antimicrobials: QACs, Triclosan, Triclocarban
- Aromatic Amines
- Arsenic
- Artificial Sweeteners
- Atrazine
- Benzene
- Bisphenols
- Cadmium
- Chlordane
- Chlorpyrifos
- DDT
- Dibutyl Phthalate
- Dichlorvos
- Dieldrin
- Dioxins
- ell/
- Ethanol (alcohol)
- Ethyl Benzene
- Ethylene Oxide
- Flame Retardants
- Food
- Formaldehyde
- Glyphosate
- Heptachlor
- Hormones
- Insulin
- Lead
- Light at Night
- Mercury
- Metals
- Methoxyclor
- Naphthalene
- Night Shift Work
- Nitrogen Dioxide
- Noise
- Oral Contraceptives
- Organochlorine Pesticides
- Organophosphate Pesticides
- Ozone
- PAHs
- Parabens
- Particulate Matter
- PCBs
- Pesticides
- PFAS
- Phenols
- Phthalates
- Processed Food
- PVC
- Radiation: Ionizing
- Radiation: Non-Ionizing
- Soda
- Stress
- Sugar
- Tobacco
- Toluene
- Trichloroethylene
- Triclosan
- Ultraviolet Radiation
- UV Filters
- Vinyl Chloride
Select the Study Tags
Sort By
- Relevance
- Title (A to Z)
- Title (Z to A)
- Publication Year (Ascending)
- Publication Year (Descending)
- Authors (A to Z)
- Authors (Z to A)
2023
PLOS Med
A large UK study of nearly 10,000 breast cancer cases found that current or recent use of progestagen-only contraceptives (including pills, injections, implants, and IUDs) was associated with a 21-32% increased breast cancer risk, similar to the risk from combined oral contraceptives containing both estrogen and progestagen. The absolute risk increase is small and age-dependent: for women using hormonal contraceptives for 5 years, the excess risk translates to 8 additional breast cancer cases per 100,000 users among women aged 16-20, but rises to 265 additional cases per 100,000 users among women aged 35-39. While these findings add important evidence about hormonal contraceptive risks, the small increased risk must be weighed against the significant benefits of contraception during childbearing years, and women should discuss their individual risk-benefit profile with their healthcare providers when choosing contraceptive methods.
2022
Cancers
This meta-analysis of nine studies involving over 33,000 women with BRCA1 or BRCA2 gene mutations. One significant finding was that women who first started using oral contraceptives at age 20 or older had a 21% increased risk of breast cancer compared to those who never used them. These findings suggest that the timing of oral contraceptive use may be important for women with BRCA mutations, though more research is needed to fully understand the relationship between hormonal contraception and cancer risk in genetic mutation carriers.
2022
Crit Rev Food Sci Nutr
A systematic review of 131 epidemiological studies examining endocrine-disrupting chemicals (EDCs) and breast cancer risk found evidence that exposure to various EDCs—including pesticides (DDT/DDE, atrazine, dioxin), synthetic chemicals (BPA, phthalates, PFAS, PCBs, PBDEs), and other compounds found in everyday products—may elevate breast cancer risk, particularly when exposure occurs during early life. The review identified food as a major route of EDC exposure and emphasized that because most EDCs persist in the environment and accumulate in the body over time, long-term multi-generational health impacts need to be assessed. The authors call for improved exposure assessments of EDCs in food and food packaging, along with careful evaluation of their links to breast cancer development to inform policy-making and regulations aimed at protecting public health.
2024
Front Glob Women’s Health
A systematic review of 51 studies (2 RCTs and 49 observational studies) examined the association between modern contraceptive use and the risk of breast and reproductive cancers in women of reproductive age. The review found that hormonal contraceptive use significantly reduced the risk of ovarian cancer by 36% and endometrial cancer, while cervical cancer rates were lower among contraceptive users compared to non-users; notably, no increased breast cancer risk was found among healthy women (RR 1.00), but BRCA1/2 mutation carriers using oral contraceptives showed a 39% increased risk of breast cancer. These findings highlight the complex cancer-related effects of hormonal contraceptives: while they offer protective benefits against ovarian and endometrial cancers for most women, BRCA mutation carriers face elevated breast cancer risk, emphasizing the need for personalized contraceptive counseling that accounts for individual genetic risk factors. The study underscores the importance of healthcare providers considering family history and genetic profiles when discussing contraceptive options with women, particularly those with hereditary cancer susceptibility.
2022
Carcinogen
A meta-analysis of 12 breast cancer studies and 8 ovarian cancer studies in women with BRCA1 or BRCA2 mutations found that oral contraceptive (OC) use was associated with a 24% increased breast cancer risk but a 47% decreased ovarian cancer risk. The increased breast cancer risk was observed only with long-term OC use (>5 years), while the ovarian cancer protection occurred regardless of duration, and these patterns were consistent when BRCA1 and BRCA2 carriers were analyzed separately. These findings present a complex risk-benefit trade-off for BRCA mutation carriers considering oral contraceptives, suggesting that while OCs provide substantial protection against ovarian cancer—a particularly deadly cancer in this high-risk population—they also modestly increase breast cancer risk with prolonged use, requiring careful individualized counseling about contraceptive choices and cancer prevention strategies.
2022
Cancers
A meta-analysis of 19 case-control studies found that oral contraceptive (OC) use had markedly different effects on breast cancer risk depending on tumor receptor status: OC use was associated with a 37% increased risk of triple-negative breast cancer and a 20% increased risk of ER-negative breast cancer, while showing an 8% reduced risk of ER-positive breast cancer and a non-significant 5% reduced risk of HER2-positive breast cancer. These contrasting associations suggest that oral contraceptives may influence breast cancer development through different biological mechanisms depending on tumor subtype, with particularly concerning implications for triple-negative breast cancer—the most aggressive subtype with limited treatment options. The findings highlight the importance of considering breast cancer heterogeneity when evaluating hormonal contraceptive risks and suggest that women at high risk for triple-negative or ER-negative breast cancer may need alternative contraceptive counseling.
2019
Medicine
A meta-analysis of 10 studies including 8,585 breast cancer cases among 686,305 participants examined the relationship between age at first oral contraceptive (OC) use and breast cancer risk through June 2018. The pooled analysis found a 24% increased breast cancer risk associated with earlier age at first OC use (RR = 1.24; 95% CI: 1.10-1.41), with a significant linear dose-response relationship indicating that younger age at first use was associated with higher breast cancer risk. However, subgroup analyses showed inconsistent results with no statistical significance when restricted to studies from Western countries, lower quality studies, smaller sample sizes, shorter follow-up periods, or when stratified by breast cancer subtypes defined by estrogen receptor (ER), progesterone receptor (PR), or HER2 status. The findings suggest that starting oral contraceptive use at a younger age may increase breast cancer risk in a dose-dependent manner, though this association appears to be influenced by study characteristics and may not differ consistently across hormone receptor-defined breast cancer subtypes, highlighting the need for further research to clarify these relationships and inform contraceptive counseling for young women.
2018
Asian Pac J Cancer Prev
A hospital-based case-control study of 762 women (381 breast cancer cases confirmed by histopathology, 381 controls) at six cancer-referral hospitals across five Indonesian provinces examined the association between oral contraceptive use and breast cancer risk. Compared to women who never used oral contraceptives, those using oral contraceptives for <6 years had nearly double the breast cancer risk (OR=1.93; 95% CI: 1.23-3.03), while those using oral contraceptives for ≥6 years had nearly triple the risk (OR=2.90; 95% CI: 1.65-5.09), demonstrating a dose-response relationship. These findings indicate that oral contraceptive use increases breast cancer risk in Indonesian women in a duration-dependent manner, with longer use associated with progressively higher risk, adding to evidence from other populations about the relationship between hormonal contraceptive use and breast cancer, though the relatively high effect sizes and hospital-based case-control design warrant careful interpretation and replication in prospective cohort studies.