OBJECTIVE: In the Women\'s Health initiative (WHI) randomized clinical trial, conjugated equine estrogen (CEE)-alone significantly reduced breast cancer incidence (P = 0.005). As cohort studies had opposite findings, other randomized clinical trials were identified to conduct a meta-analysis of estrogen-alone influence on breast cancer incidence.
METHODS: We conducted literature searches on randomized trials and: estrogen, hormone therapy, and breast cancer, and searches from a prior meta-analysis and reviews. In the meta-analysis, for trials with published relative risks (RR) and 95% confidence intervals (CI), each log-RR was multiplied by weight = 1/V, where V = variance of the log-RR, and V was derived from the corresponding 95% CI. For smaller trials with only breast cancer numbers, the corresponding log-RR = (O - E)/weight, where O is the observed case number in the oestrogen-alone group and E the corresponding expected case number, E = nP.
RESULTS: Findings from 10 randomized trials included 14,282 participants and 591 incident breast cancers. In 9 smaller trials, with 1.2% (24 of 2029) vs 2.2% (33 of 1514) randomized to estrogen-alone vs placebo (open label, one trial) (RR 0.65 95% CI 0.38-1.11, P = 0.12). For 5 trials evaluating estradiol formulations, RR = 0.63 95% CI 0.34-1.16, P = 0.15. Combining the 10 trials, 3.6% (262 of 7339) vs 4.7% (329 of 6943) randomized to estrogen-alone vs placebo (overall RR 0.77 95% CI 0.65-0.91, P = 0.002).
CONCLUSIONS: The totality of randomized clinical trial evidence supports a conclusion that estrogen-alone use significantly reduces breast cancer incidence.

Both body mass index (BMI) and family history of cancer are established risk factors for female breast cancer. However, few studies explored the potential interaction between both factors. We assessed the association of BMI and its interaction with family cancer history on the risk of female breast cancer in Shanghai, China. Based on a population-based prospective cohort study started from 2008 to 2012 with 15,055 Chinese female participants in Minhang district, Shanghai. Cox regression models were used to estimate the association of BMI and its interaction with a family history of cancer on breast cancer risk. The additive interaction was evaluated by the relative excess risk due to interaction (RERI) and the attributable proportion due to interaction (AP), and the multiplicative interaction was assessed by the product term (BMI* family history of cancer) in the Cox regression model. Compared with BMI of < 24 kg/m2 and no family history of cancer, women with BMI of ≥ 24 kg/m2 and a family history of cancer had a higher risk for breast cancer with HR 2.06 (95% CI 1.39, 3.06). There was an additive interaction between BMI and family history of cancer on breast cancer incidence, with the RERI being 0.29 (95% CI 0.08, 0.51) and the AP being 0.37 (95% CI 0.08, 0.66). The coexistence of obesity and cancer family history may exacerbate breast cancer incidence risk, highlighting the importance of weight management in women with a family history of cancer.

BACKGROUND: Breast cancer is the most common cancer and the leading cause of cancer-related death among women. However, evidence concerning hematological and biochemical markers influencing the natural history of breast cancer from in situ breast cancer to mortality is limited.
METHODS: In the UK Biobank cohort, 260,079 women were enrolled during 2006-2010 and were followed up until 2019 to test the 59 hematological and biochemical markers associated with breast cancer risk and mortality. The strengths of these associations were evaluated using the multivariable Cox regression models. To understand the natural history of breast cancer, multi-state survival models were further applied to examine the effects of biomarkers on transitions between different states of breast cancer.
RESULTS: Eleven biomarkers were found to be significantly associated with the risk of invasive breast cancer, including mainly inflammatory-related biomarkers and endogenous hormones, while serum testosterone was also associated with the risk of in-situ breast cancer. Among them, C-reactive protein (CRP) was more likely to be associated with invasive breast cancer and its transition to death from breast cancer (HR for the highest quartile = 1.46, 95 % CI = 1.07-1.97), while testosterone and insulin-like growth factor-1 (IGF-1) were more likely to impact the early state of breast cancer development (Testosterone: HR for the highest quartile = 1.31, 95 % CI = 1.12-1.53; IGF-1: HR for the highest quartile = 1.17, 95 % CI = 1.00-1.38).
CONCLUSIONS: Serum CRP, testosterone, and IGF-1 have different impacts on the transitions of different breast cancer states, confirming the role of chronic inflammation and endogenous hormones in breast cancer progression. This study further highlights the need of closer surveillance for these biomarkers during the breast cancer development course.

OBJECTIVE: The aim of this study was to identify the mean age at which breast cancer (BC) was first diagnosed in 2010 or 2022, and to evaluate whether there were any changes in age groups at first BC diagnosis.
METHODS: This retrospective cross-sectional study included adult women (18 years or older) who were diagnosed with BC (ICD-10: C50) for the first time in 2010 or 2022 in office-based practices in Germany (in 300 general practices or 95 gynecological practices). We examined the mean age at diagnosis and the percentage of patients in three age groups (18-49, 50-65, and > 65) for both 2010 and 2022. The average age difference between 2010 and 2022 was analyzed using Wilcoxon rank tests, and the proportions of the three age groups were analyzed using chi-squared tests. These analyses were performed separately for patients in general and gynecological practices.
RESULTS: The mean age at which BC was initially diagnosed in 2022 was found to be significantly greater than that in 2010 for both general practices (66.9 years vs. 64.0 years p < 0.001) and gynecological practices (62.2 years vs. 60.3 years, p < 0.001). Early-onset BC decreased from 15.6 to 12.0% in general practices and from 23.2 to 18.2% in gynecological practices between 2010 and 2022. The proportion of new BC diagnoses in the age group 50-65 increased from 36.6 to 40.9% in gynecological practices, but did not increase in general practices.
CONCLUSIONS: The study found that BC was diagnosed at an older age in 2022 than in 2010. In addition, the proportion of early-onset BC cases decreased, while the proportion of cases in the age group 50-65 increased in gynecological practices in Germany.

暂无摘要。

The incidence and mortality data for patients with breast cancer in the United States are important to healthcare administrators for planning healthcare measures such as screening mammograms. In this study, we examined breast cancer incidence and incidence-based mortality in the United States from 2004-2018 using the Surveillance, Epidemiology, and End Results (SEER) database. We reviewed 915,417 cases of breast cancer diagnosed between 2004 and 2018. Overall, the data showed an increased incidence rate of breast cancer among all races and a decreased mortality rate among all races. Breast cancer incidence rates increased by 0.3% (95% CI, 0.1, 0.4, p<0.001) per year over the study period. Breast cancer incidence rates increased for all age, race, and stage groups except for stage regional, which showed a statistically significant decrease in the incidence of -0.9% (95% CI, -1.1, -0.7, p<0.001). The highest decrease in mortality was observed among white patients, with an overall statistically significant decrease in rates by -14.3% (95% CI, -18.1, -10.4, p <0.001). The highest decrease in rates was observed between 2016 and 2018: -48.6 (95% CI, -52.6, -44.3, p <0.001). In black/African American patients, the overall incidence-based mortality decreased by -11.6% (95% CI -15.9, -7.1 p <.001), with the highest decrease in rates observed between 2016 and 2018 with a decrease of -51.3% (95% CI -56.6, -45.3, p <0.001). In Hispanic Americans, the overall incidence-based mortality decreased by -12.3% (95% CI -16.9, -7.4, p <.001), which is lower than in white Americans.

OBJECTIVE: To identify predictors of screening mammography use and the effect of screening mammography on breast cancer mortality in North Carolina.
METHODS: This cross-sectional study integrated publicly available data from government and private data repositories to model predictors of screening mammography and breast cancer mortality in North Carolina.
RESULTS: In North Carolina during 2008-2010, on average, 68.1% of women aged 40-74 years underwent a screening mammogram in the previous two years (range: 38.7%-82.1). The ordinary least squares (OLS) regression demonstrated counties experiencing persistent poverty have mammography screening rates that are 4.3% less, on average, than counties without persistent poverty (estimate (SE) = - 4.283 (2.105), p = 0.045). As the percentage of women with a college education increases, the mammography screening rates increase by approximately 0.3% (estimate (SE) = 0.319 (0.078), P < .001) and as the health literacy score increases, the mammography screening rate decreases by 0.3% (estimate (SE) = - 0.318 (0.104), p = 0.003). These variables explain 7.0% of the variability in mammographic screening rates. The OLS regression analysis demonstrated that age-adjusted breast cancer incidence (Estimate (SE) = 0.074 (0.024), p = 0.003) and health literacy score (estimate (SE) = - 0.175 (0.083), p = 0.039) are significantly related to breast cancer mortality.
CONCLUSIONS: Demographic, socioeconomic, and environmental variables explain only a small percentage of the variability in the rates of screening mammography and breast cancer mortality in North Carolina. Advances in the available treatments are likely the major contributor to improving breast cancer mortality.

We examined the effects of the COVID-19 pandemic on the screening, diagnosis and treatment of breast cancer in Hungary based on administrative data until June 2021, covering three pandemic waves. After correcting for trend and seasonality, the number of mammography examinations decreased by 68% in 2020q2, was around its usual level in 2020q3 and was reduced by 20-35% throughout 2020q4-2021q2. The reduction was caused by a combination of supply-side (temporary suspensions of screening) and demand-side (lower screening participation during the pandemic waves) factors. The number of new breast cancer diagnoses and mastectomy surgeries responded with a lag, and were below their usual level by 15-30% in all quarters between 2020q2 and 2021q2, apart from 2020q4, when there was no significant difference. Using a regression discontinuity framework, we found that the partial mastectomy rate (indicative of early diagnosis) dropped more substantially in 2020q2 in the 61-65 years old age group that was just below the age cut-off of organized screening than in the 66-70 years old age group, and this difference was partially offset in 2021q1. We suggest that policymakers need to motivate the target population (by providing both information and incentives) to catch up on missed screenings.

OBJECTIVE: The early months of the COVID-19 pandemic led to reduced cancer screenings and delayed cancer surgeries. We used insurance claims data to understand how breast cancer incidence and treatment after diagnosis changed nationwide over the course of the pandemic.
METHODS: Using the Optum Research Database from January 2017 to March 2021, including approximately 19 million US adults with commercial health insurance, we identified new breast cancer diagnoses and first treatment after diagnosis. We compared breast cancer incidence and proportion of newly diagnosed patients receiving pre-operative systemic therapy pre-COVID, in the first 2 months of the COVID pandemic and in the later part of the COVID pandemic.
RESULTS: Average monthly breast cancer incidence was 19.3 (95% CI 19.1-19.5) cases per 100,000 women and men pre-COVID, 11.6 (95% CI 10.8-12.4) per 100,000 in April-May 2020, and 19.7 (95% CI 19.3-20.1) per 100,000 in June 2020-February 2021. Use of pre-operative systemic therapy was 12.0% (11.7-12.4) pre-COVID, 37.7% (34.9-40.7) for patients diagnosed March-April 2020, and 14.8% (14.0-15.7) for patients diagnosed May 2020-January 2021. The changes in breast cancer incidence across the pandemic did not vary by demographic factors. Use of pre-operative systemic therapy across the pandemic varied by geographic region, but not by area socioeconomic deprivation or race/ethnicity.
CONCLUSIONS: In this US-insured population, the dramatic changes in breast cancer incidence and the use of pre-operative systemic therapy experienced in the first 2 months of the pandemic did not persist, although a modest change in the initial management of breast cancer continued.

Limited evidence exists on the relationship between exposure to endocrine-disrupting metals in ambient air and hormone receptor- and HER2-dependent breast cancer. This study investigates the association between ambient air emissions of endocrine-disrupting metals and the incidence of female breast cancer of different receptor status. County-level data from the US national datasets were analyzed for the association between emissions of various metals including arsenic, cadmium, chromium VI, lead, and mercury, and the annual age-adjusted incidence of hormone receptor-dependent breast cancer for 1990-2016 and HER2-dependent breast cancer for 2010-2016 using adjusted linear regression models. Lead emissions showed the strongest association among the metals examined with the incidence of different receptor status breast cancers, including ER-positive, ER-negative, PR-negative, HER2-negative, and Triple-negative breast cancers, with the adjusted β ranging from 917.26 for ER-negative to 3182.37 for HER2-negative breast cancer. Arsenic and mercury showed significant associations with the incidence of ER-positive, ER-negative, PR-positive, and PR-negative breast cancers. However, cadmium emissions were only significantly associated with ER-negative breast cancer. Moreover, chromium was not associated with any subtypes of breast cancer. Among all of the metals, only lead and mercury emissions showed significant associations with HER2-negative and Triple-negative breast cancer incidence. The results from this study suggest that increased exposure to endocrine-disrupting metals, especially lead, in ambient air could be associated with an increased incidence of female breast cancers with various receptor status in the US. Prospective studies are warranted to further explore this relationship.