Factors associated with insufficient awareness of breast cancer among women in Northern and Eastern China: a case-control study

Survey of awareness and beliefs about cancer (ABC) in Tehran Province, Iran

INTRODUCTION

Knowledge, attitudes, and practices are essential measures for planning and evaluating cancer control programs. Little is known about these in Iran.

METHODS

We conducted a population-based interview survey of adults aged 30-70 using the Farsi version of the Awareness and Beliefs about Cancer questionnaire in the capital province of Tehran, Iran, 2019. We calculated weighted estimates of levels of cancer knowledge, attitudes, and practices to allow for different selection probabilities and nonresponse. We used multivariate logistic regression to understand demographic factors associated with bowel, cervix, and breast screening practices.

RESULTS

We interviewed 736 men and 744 women. The mean number of recalled cancer warning signs was less than one; 57.7% could not recall any cancer warning signs. Participants recognized 5.6 out of 11 early cancer warning signs and 8.8 of 13 cancer risk factors. Most (82.7%) did not know that HPV infection was a cancer risk factor. Approximately, half had negative attitudes towards cancer treatment, but over 80% had positive attitudes towards the effectiveness of screening for improving survival. Colorectal, breast, and cervical screening rates were 24%, 42%, and 49%, respectively. Higher socioeconomic status increased the odds of taking up screening for cancer. Women aged 60-70 were less likely to report taking up breast and cervical screening than younger women.

DISCUSSION

The Iranian population has poor awareness and negative attitudes about cancer, and participation in screening programs is low. Public awareness and early detection of cancer should be promoted in Iran.

Factors Influencing Breast Cancer Awareness in Rural Southwest China: A Cross-Sectional Study

Background

This study aimed to explore the current knowledge level of breast cancer among rural women in Southwest China and analyze the influencing factors of breast cancer cognition.

Methods

From May to November 2022, 1468 rural women were invited to participate in this study. Demographic information and the Chinese version of the Breast Cancer Awareness Measure (C-BCAM) were collected through one-on-one investigations. The data were analyzed using descriptive statistics, chi-square tests, and multiple regression analysis in SPSS 26.0.

Results

The study included a total of 1468 rural women with a median age of 54.0 (IQR, 47.0, 60.0).The average score of breast cancer in the study population was 73.0 (IQR, 66.0, 82.0). Among women in Southwest China, the awareness rates of knowledge on breast cancer symptoms, barriers to seeking medical help, and risk factors were 68.8%, 98.4%, and 62.1%, respectively. The awareness rate was found to increase with higher education levels (P<0.001) and decrease with increasing age (P<0.001). Multivariate logistic regression analysis identified three variables that might influence breast cancer awareness: education level, contraceptive measures, and history of breast disease (all P<0.05). Specifically, history of breast disease (Odds ratio (OR) = 1.907, 95% CI = 1.128 ~ 3.223), middle school education (OR = 2.155, 95% CI = 1.585 ~ 2.928), and junior college education and above (OR = 5.536, 95% CI = 1.898 ~ 16.148) were positive factors for women's breast cancer awareness. Conversely, the use of intrauterine devices (OR = 0.523, 95% CI = 0.384 ~ 0.712) was found to be a negative factor for women's breast cancer awareness.

Conclusion

This study highlights the insufficient awareness of breast cancer among women in rural area of Southwest China. It emphasizes the necessity of health education to improve female breast cancer awareness.

Incidence, mortality, survival, and disease burden of breast cancer in China compared to other developed countries

Breast cancer was the most diagnosed malignant neoplasm and the second leading cause of cancer mortality among Chinese females in 2020. Increased risk factors and widespread adoption of westernized lifestyles have resulted in an upward trend in the occurrence of breast cancer. Up to date knowledge on the incidence, mortality, survival, and burden of breast cancer is essential for optimized cancer prevention and control. To better understand the status of breast cancer in China, this narrative literature review collected data from multiple sources, including studies obtained from the PubMed database and text references, national annual cancer report, government cancer database, Global Cancer Statistics 2020, and Global Burden of Disease study (2019). This review provides an overview of the incidence, mortality, and survival rates of breast cancer, as well as a summary of disability-adjusted life years associated with breast cancer in China from 1990 to 2019, with comparisons to Japan, South Korea, Australia and the United States.

Investigation on sexual function in young breast cancer patients during endocrine therapy: a latent class analysis

Backgrounds

The aim of this study was to investigate the sexual function status of young breast cancer patients during endocrine therapy, identify potential categories of sexual function status, and analyze the factors affecting the potential categories of sexual function status during endocrine therapy.

Methods

A cross-sectional survey was conducted on 189 young breast cancer patients who underwent postoperative adjuvant endocrine therapy in Shanghai Ruijin Hospital. The latent class analysis was used to identify potential categories of patient sexual function characteristics with respect to the FSFI sex health measures. Logistic regression analysis was used to analyze the influencing factors for the high risk latent class groups. A nomogram prognostic model were then established to identify high risk patients for female sexual dysfunction (FSD), and C-index was used to determine the prognostic accuracy.

Results

Patients were divided into a "high dysfunction-low satisfaction" group and a "low dysfunction-high satisfaction" group depending on the latent class analysis, accounting for 69.3% and 30.7%, respectively. Patients who received aromatase inhibitors (AI) combined with ovarian function suppression (OFS) treatment (p = 0.027), had poor body-image after surgery (p = 0.007), beared heavy medical economy burden(p < 0.001), and had a delayed recovery of sexual function after surgery (p = 0.001) were more likely to be classified into the "high dysfunction-low satisfaction" group, and then conducted into the nomogram. The C-index value of the nomogram for predicting FSD was 0.782.

Conclusion

The study revealed the heterogeneity of sexual function status among young breast cancer patients during endocrine therapy, which may help identify high-risk patients and provide early intervention.

Co-Creation of Breast Cancer Risk Communication Tools and an Assessment of Risk Factor Awareness: A Qualitative Study of Patients and the Public in India

BACKGROUND

Low awareness of BC and its associated risk factors causes delays in diagnosis and impacts survival. It is critical to communicate BC risk to patients in a format that they are easily able to understand. Our study aim was to develop easy-to-follow transmedia prototypes to communicate BC risk and evaluate user preferences, alongside exploring awareness of BC and its risk factors.

METHODS

Prototypes of transmedia tools for risk communication were developed with multidisciplinary input. A qualitative in-depth online interview study was undertaken using a pre-defined topic guide of BC patients (7), their relatives (6), the general public (6), and health professionals (6). Interviews were analyzed using a thematic approach.

FINDINGS

Most participants preferred pictographic representations (frequency format) of lifetime risk and risk factors and storytelling using short animations and comic strips (infographics) for communicating genetic risk and testing: "In a short time, they explained it very well, and I liked it". Suggestions included minimizing technical terminology, decreasing the delivery speed, "two-way dialogue", and using local "language for different locations". There was low awareness of BC, with some understanding of age and hereditary risk factors but limited knowledge of reproductive factors.

INTERPRETATION

Our findings support use of multiple context-specific multimedia tools in communicating cancer risk in an easy-to-understand way. The preference for storytelling using animations and infographics is a novel finding and should be more widely explored.

Assessing Syrian women's knowledge of breast cancer risk factors, warning signs, and barriers to preventive measures: A cross-sectional study

BACKGROUND

This study aims to investigate the knowledge of Syrian women about breast cancer risk factors, warning signals, and barriers. Breast cancer is the most common cancer worldwide and the leading cause of cancer death among women. It develops when cells in the breast tissue grow uncontrollably, forming a tumor that can spread to other parts of the body.

MATERIALS AND METHODS

This survey was conducted online from September 3 to September 27, 2022, and focused on Syrian women over the age of 18. It was divided into two sections, one focusing on sociodemographic characteristics and the other on breast cancer risk factors, warning signals, and barriers.

RESULTS

This study found that the majority of the 1305 participants had inadequate knowledge of breast cancer risk factors, warning signs, and barriers. Those with higher levels of education, such as Ph.D. students, had the highest overall scores. The sample was mostly made up of housewives, married women, and women with moderate monthly incomes.

CONCLUSION

This research found that Syrian women have inadequate knowledge about breast cancer, including risk factors, warning signs, and barriers. To reduce mortality rates, increase survival rates, and improve early diagnosis, local health organizations should provide awareness courses to emphasize the importance of annual breast exams.

Factors associated with awareness of breast cancer among women of reproductive age in Lesotho: a national population-based cross-sectional survey

BACKGROUND

Breast cancer is a leading cause of cancer mortality and a major public health problem. The growing number of breast cancer-related deaths has been largely attributed to a lack of awareness of the disease among women. Whilst there have been frequent campaigns promoting breast cancer awareness, evidence suggests that women still lack awareness. Therefore, this study assessed the prevalence and factors associated with the awareness of breast cancer among women of reproductive age in Lesotho.

METHODS

We used population-based cross-sectional data from the 2014 Lesotho Demographic and Health survey. A total of 6,620 women of reproductive age were included in the analysis. The outcome variable was awareness of breast cancer. Women who heard about breast cancer were considered to be aware of the disease. Multilevel binary logistic regression models were fitted to determine the factors associated with breast cancer awareness among women.

RESULTS

The level of awareness of breast cancer was 86.8% (95% CI: 85.5, 87.9). Women aged 45-49 years [adjusted odds ratio (AOR) = 2.87, 95% confidence interval (CI): 1.83, 4.48], married women [AOR = 1.51 (95% CI: 1.19, 1.93)], and women with higher educational level [AOR = 12.56, (95% CI: 4.35, 36.28)] were more likely to be aware of breast cancer. Additionally, women who listened to the radio at least once a week [AOR = 1.96, (95% CI: 1.63, 2.37)], those who read newspapers or magazines [AOR = 1.91 (95% CI: 1.48, 2.46)] and women in the wealthiest group [AOR = 2.55, (95% CI: 1.67, 3.89)] had higher odds of breast cancer awareness. However, women who were in rural areas were less likely [AOR = 0.63, (95% CI: 0.47, 0.84)] to be aware of breast cancer than those in urban areas.

CONCLUSION

The level of awareness of breast cancer among women of reproductive age in Lesotho was extremely low. We recommend that policymakers, clinicians, and public health practitioners should consider the factors identified in this study when designing and developing intervention programs to improve the awareness of breast cancer among women in Lesotho.

A national survey to assess breast cancer awareness among the female university students of Pakistan

The incidence of breast cancer is increasing in Pakistan as well as globally. Awareness of women about breast cancer plays a cornerstone role in its early detection, better management, and prevention. Keeping this in mind, a cross-sectional study was carried out to assess the awareness of female university students about breast cancer’s risk factors, signs and symptoms, and breast cancer examination. The data was collected from female university students studying in Pakistan. A total of 774 participants completed the survey and recorded their responses on an online pre-tested self-administered questionnaire. Only 29.8% of the participants have identified breast cancer history in their first-degree relatives as a risk factor. Moreover, 14.1% of the participant considered that the use of oral contraceptives for more than 5 years can increase the risk of developing breast cancer. In addition, inward pulled nipple, wounds around the nipple, and abrupt changes in the breast size were considered as the sign and symptoms of breast cancer by 25.2%, 25.7%, and 31.7% of the participants, respectively. Moreover, only 20.9% of the participants identified the correct year for starting breast cancer examination and 44.4% of the respondents marked that mammography should be initiated after 40 years. Overall, the university female students of Pakistan were poorly aware of breast cancer’s risk factors, signs and symptoms, and breast examination. This study has highlighted the need for initiation of aggressive strategies regarding breast cancer awareness in both the literate and illiterate female population of Pakistan.

Linking Risk Perception to Breast Cancer Examination Intention in China: Examining an Adapted Cognitive Mediation Model

Drawn upon the cognitive mediation model, this study proposes an adapted model and examines the mechanisms by which Chinese women's risk perception of breast cancer becomes associated with their breast cancer examination intention. Our hypothesized model was largely supported by an online survey with a nationwide sample of 458 Chinese women. The results indicated that a person's perceived risk for breast cancer motivated information seeking and scanning using various mass media and online channels, which then positively predicted the person's quest for greater elaboration and more interpersonal discussion. In addition, elaboration was positively associated with breast cancer-related factual knowledge and subjective norms, whereas interpersonal discussion only exerted a positive relationship with subjective norms but not factual knowledge. As predicted, knowledge and subjective norms were positively associated with people's intentions to pursue breast cancer examination. Future research should consider both information seeking and scanning in the process of media learning and reflection. In addition to intrapersonal factors like knowledge, the interpersonal reasoning process that cultivates a favorable social influence is pivotal in promoting breast cancer examination in China.

Determinants of Intention to Participate in Breast Cancer Screening among Urban Chinese Women: An Application of the Protection Motivation Theory

Despite the significance of early detection of breast cancer through screening, the screening uptake in China remains relatively low. Protection motivation theory (PMT) suggested by Rogers is one of the theories concerning threat appeal. This study aimed to apply the protection motivation theory (PMT) in predicting breast cancer screening intention. In this cross-sectional study, a sample of Chinese urban women was recruited using the convenient sampling method from five communities in Wuhan. Data were collected using a self-report questionnaire that included demographic variables, knowledge about breast cancer, six PMT subconstructs, and screening intention. We used the structural equation modeling (SEM) to identify the predictor factors associated with screening intention. Of the total sample (n = 412), 86.65% had intention to participate in screening. Our data fit the hypothesized SEM model well (Goodness of fit index (GFI) = 0.91, adjusted GFI (AGFI) = 0.89, comparative fit index (CFI) = 0.91, root mean square error of approximation (RMSEA) = 0.05, standardized root mean residual (SRMR) = 0.06, and Chi-square/df = 2.01). Three PMT subconstructs (perceived severity, response cost, and self-efficacy) were significantly associated with screening intention. Knowledge, social status, and medical history had significantly indirect associations with screening intention through the mediating effect of PMT subconstructs. Considering the utility of PMT, intervention programs might be more effective based on the subconstructs of PMT, especially to improve self-efficacy, perceived severity, and knowledge, reduce response cost, as well as targeting specific demographic groups.

Detection rate is not higher for women with BBD history in breast cancer screening

BACKGROUND

To investigate whether women with benign breast disease (BBD) history have higher breast cancer detection rate in screening.

METHODS

We reviewed data for 33 001 female participants in Multi-modality Independent Screening Trial (MIST). Corresponding data for 6823 breast cancer patients were retrieved from the Tianjin Breast Cancer Cases Cohort (TBCCC) and analyzed for comparison.

RESULTS

The breast cancer detection rate was 2.83‰ among women with BBD history and 3.28‰ in women without. Moreover, the proportion of carcinoma in situ (CIS) was also lower in women with BBD history than women without (7.69 versus 20.31%). In contrast, analysis of TBCCC data revealed a higher proportion of CIS in patients with BBD history (5.05%) than patients without (3.26%). Our data showed that a larger proportion of women with BBD history had undergone previous breast examinations. Additionally, among participants diagnosed with both breast cancer and BBD in MIST, we found a lower proportion of CIS in women with BBD history (11.76%) compared to women without (32.14%).

CONCLUSIONS

Women with BBD history were not found to have higher detection rate in breast cancer screening. Women with BBD history were more likely to be proactive in seeking breast examinations and to have breast cancer be diagnosed in clinic.

Factors influencing breast cancer awareness: a cross-sectional study in China

Aim: This study aimed to explore the factors that influence breast cancer awareness. Materials & methods: A community-based cross-sectional study was conducted between January and April 2019 in Changchun, Jilin Province, China. Results: A total of 274 women were recruited for this cross-sectional study. Participants had a moderate level of breast cancer awareness (median = 76.50 [68.75, 84.00]). Women in the action/maintenance stages reported higher breast cancer awareness (p = 0.044). Women's breast cancer awareness was positively associated with high health information literacy level, husbands' higher educational degrees, seeing doctors after detecting abnormal breast changes and living within a short distance from the nearest hospital. Conclusion: History of screening and higher health information literacy levels are important positive factors linked to higher breast cancer awareness.

Co-occurrence of PML-RARA gene fusion, chromosome 8 trisomy, and FLT3 ITD mutation in a young female patient with de novo acute myeloid leukemia and early death: A CARE case report

RATIONALE

Co-occurrence of cytogenetic and molecular abnormalities is frequently seen in patients with acute myeloid leukemia (AML). The clinical outcome and genetic abnormalities of AML may vary; therefore, genetic investigation must be complex, using several techniques, to have an appropriate characterization of the AML genome and its clinical impact. The available molecular markers can predict prognosis only partially. Acute promyelocytic leukemia subtype M3 (AML M3) is a subtype of AML characterized by the presence of promyelocytic leukemia-retinoic acid receptor alpha (PML-RARA) genes fusion. Targeted treatment with all-trans-retinoic acid (ATRA) and ATRA combined with arsenic trioxide significantly improved the survival of AML M3 patients. Unknown prognostic factors could contribute to the early death of these patients.

PATIENT CONCERNS

We present the case of a young female (20 years old) patient, who presented at the emergency department 5 months after giving birth to her first child, complaining of asthenia, fatigue, general musculoskeletal pain, and fever (38°C), symptoms having been present for the previous 6 days. The patient denied any chronic diseases in her medical and family history.

DIAGNOSIS

Laboratory analysis revealed severe pancytopenia. Cytogenetic and molecular analyzes revealed chromosomal abnormalities (trisomy 8), PML-RARA gene fusion, and fms-like tyrosine kinase 3 (FLT3) gene mutation. The immunophenotypic analysis was also suggestive for AML M3 according to the FAB classification.

INTERVENTIONS

Specific treatment was initiated for AML M3 and for secondary conditions. Molecular and cytogenetic analyzes were performed to have a more detailed characterization of the patient's genome.

OUTCOME

Seventy-two hours after admission, she developed psychomotor agitation, confusion, coma, and convulsion. Subsequent deterioration and early death were caused by intracerebral hemorrhage with multiple localization and diffuse cerebral edema.

LESSONS

The presence of FLT3 internal tandem duplication (ITD) mutation may explain the rapid and progressive degradation of this AML M3 case and it may be used as a prognostic marker even when co-occuring with other markers such as PML-RARA gene fusion and trisomy 8. We consider that FLT3 ITD mutation analysis in young patients with AML should be performed as soon as possible. New strategies for patients' education, AML (or cancers in general) prevention, and treatment are needed.

Knowledge towards Cervical and Breast Cancers among Industrial Workers: Results from a Multisite Study in Northern Vietnam

Breast and cervical cancer cases are rising among service and industrial women workers in Vietnam. We conducted a cross-sectional study among 287 workers in three factories in Hanoi and Bac Ninh from July to September 2018 to describe the knowledge of these cancers among industrial workers in Northern Vietnam using a structured questionnaire. Factors associated with knowledge of breast and cervical cancer were identified using generalized linear models (GLM). In our study, approximately one-third of participants believed breast cancer was caused by the lack of breastfeeding, exposure to pollution, and chemicals. Less than 50% knew about sexually transmitted infections that can cause cervical cancer or were aware of a vaccine for cervical cancer. Having one sexual partner within the last year was positively associated with having a higher score of knowledge for both diseases. Receiving a medical checkup within the last 12 months and seeking health information via the internet were related to greater breast cancer knowledge. Targeted education campaigns are needed to ensure proper knowledge and improve awareness of breast cancer and cervical cancer among industrial workers.

Awareness on breast cancer screening in Malaysia: a cross sectional study

INTRODUCTION

The increasing rate of breast cancer (BC) incidence in Malaysia hints a lack of awareness among Malaysians. One (1) woman out of nineteen (19) is at risk with BC and almost up to fifty percent (50%) of women diagnosed with BC were reported to be under the age of fifty (50). Our main concern is to study the level of awareness among the women on risk factors, clinical manifestations, diagnosis, preventions and treatments.

METHOD

A cross-sectional study was conducted exclusively among women in the public with total sample of three hundred and forty six (346), questionnaires were distributed using a simple random technique. Data was collected and analyzed by student T test in SPPS version 20.

RESULTS

Our study reveals insufficient awareness on BC. Overall, awareness on risk factors is inadequate, but good knowledge on the importance of family history and diet as risk factors are discovered. Awareness on the cause and clinical manifestations of BC is required for improvement. As for treatment, alternatives especially surgery and chemotherapy are unclear to public, public is remotely unwitting on cessation of smoking to prevent BC at the early stage.

CONCLUSION

Malaysian has spaces for improvement on awareness of BC in terms of risk factors, clinical manifestations, diagnosis, treatment and prevention. Early detection can be achieved with good awareness because it leads to better prognosis and lower mortality.

Factors associated with breast cancer screening participation among women in mainland China: a systematic review

OBJECTIVES

Although detecting breast cancer at an early stage through screening has been clearly shown to be an effective strategy, the screening participation rate in China remains low. This systematic review sought to synthesise the current evidence to identify factors associated with breast cancer screening participation among women in mainland China.

DESIGN

This study was a systematic review.

DATA SOURCES

Studies were collected from PubMed, PsycINFO, CINAHL, EMBASE and three major Chinese databases, specially China National Knowledge Infrastructure, Chongqing VIP and Wanfang Data.

ELIGIBILITY CRITERIA

All included papers were original research studies with a longitudinal or cross-sectional study design that considered associated factors of breast cancer screening participation among women in mainland China.

DATA EXTRACTION AND SYNTHESIS

Study selection, data extraction and quality assessment were conducted independently by two reviewers, involving a third to help reach a consensus when necessary. Primary outcomes of interest included factors associated with breast cancer screening participation.

RESULTS

A total of 19 studies were included in this review. Based on these studies, geographical region, a personal history of breast disease, past screening behaviours for breast disease, physical examination and the availability of medical specialists/equipment for breast examination were consistently associated with participation in breast cancer screening, while residential area, ethnicity and attitude towards breast cancer screening appeared to be associated with participation in breast cancer screening. There were additionally some factors with even more limited evidence with which to ascertain their association with screening participation.

CONCLUSIONS

There exists a wide range of factors that influence breast cancer screening participation in mainland China. These findings could help to inform future research and policy efforts.

Cultural beliefs about breast cancer in Vietnamese women

Background

This study examined factors influencing cultural beliefs associated with later-stage detection of breast cancer and determined what factors influence those cultural beliefs in Vietnamese women residing in a rural Vietnamese community.

Methods

A cross-sectional survey was conducted with 289 women aged 20–64 years from 12 villages using a self-administered structured questionnaire. Cultural beliefs were measured with a 13-item cultural beliefs scale consisting of four domains—characteristics of breast lumps, self-help techniques, faith-based beliefs, and futility of treatment. Data were collected in February 2017 and analyzed using chi-square tests, nonparametric tests, Fisher’s exact tests, and multiple linear regression analyses with SPSS/WIN 24.0 statistical software.

Results

Although the total score was relatively low (3.4 out of 13), cultural beliefs that could contribute to later-stage breast cancer were identified. Younger women (β = .15, p = .016) and women with a lower income (β = .21, p < .001) held more erroneous cultural beliefs as compared to their counterparts. Most women believed they would not get breast cancer if they took care of themselves. More than one-third held cultural beliefs about breast lumps, thinking they would need to be painful and/or actively growing to be breast cancer.

Conclusions

The results support the urgent need for education concerning breast cancer health promotion, including breast cancer assessment as well as guidance on evidence-based and up-to-date detection measures to change rural Vietnamese women’s cultural beliefs.

Electronic supplementary material

The online version of this article (10.1186/s12905-019-0777-3) contains supplementary material, which is available to authorized users.

Higher frequency of dairy intake is associated with a reduced risk of breast cancer: Results from a case-control study in Northern and Eastern China

The association between dairy intake and breast cancer risk has not been well investigated, especially in the Chinese population. This study aimed to examine the association between the weekly frequency of dairy intake and the risk of breast cancer among women in Northern and Eastern China, and to investigate whether the association varied by hormone receptor status. A total of 1,286 cases of breast cancer and 1,461 controls were enrolled in this study. Dairy intake was obtained using a food-frequency questionnaire (FFQ). Frequency of dairy intake per week was divided into four categories (<1 day/week, 1–2 days/week, 3–4 days/week and 5–7 days/week). Unconditional multivariate logistic regression analysis was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CI). Stratified analyses were performed by residence, age, and education level. Separate analyses were also conducted for different estrogen receptor (ER) and progesterone receptor (PR) status. This analysis revealed that weekly frequency of dairy intake was strongly inversely associated with breast cancer risk, with an adjusted OR for intake 5–7 days/week of 0.53 (95% CI=0.39–0.72, P<0.001 for trend). In the stratified analyses, women who consumed dairy 5–7 days/week had a lower risk of breast cancer in urban areas (OR=0.45, 95% CI=0.30–0.66, P<0.001 for trend), in the group 45–59 years old (OR=0.39, 95% CI=0.26–0.60, P<0.001 for trend), and in the group educated to senior high school or above (OR=0.39, 95% CI=0.25–0.59, P<0.001 for trend). There was an inverse association between the weekly frequency of dairy intake and the risk of ER⁺, PR⁺, and ER⁺PR⁺ breast cancer (all P<0.001 for trend). These results indicated that the weekly frequency of dairy intake was inversely associated with the risk of breast cancer among women in Northern and Eastern China.