Black-White Breast Cancer Incidence Trends: Effects of Ethnicity

Geographical variations of cancer incidence in Guadeloupe, French West Indies

Background

Geographical disparities in cancer incidence are observed at different scales and may highlight areas of high risk that need special attention to improve health policies. In Guadeloupe, a French archipelago in the Caribbean, environmental and socioeconomic factors are potential factors associated with cancer incidence. Our objective was to describe geographical variations of cancer incidence in Guadeloupe at a small-area level, in order to identify potential clusters.

Methods

We conducted spatial analyses for the 18 most frequent cancer sites, using data collected by the population-based cancer registry of Guadeloupe over the period 2008–2017. For each cancer sites, we used the Besag, York and Mollié model to estimate smoothed standardized incidence ratios (SIRs) at a sub-municipality level. In addition, we performed ascendant hierarchical clustering of these smoothed SIRs to describe the relationship between the different cancer sites and to identify geographical clusters.

Results

We observed geographical disparities with a spatial pattern that varied across cancer sites. Clustering of the smoothed SIRs showed aggregations between breast cancer and multiple myeloma, thyroid and stomach cancer, cervical and head and neck cancers, lung and rectal cancers, ovarian and endometrial cancers. Cluster analysis also identified six geographical clusters. Features of these clusters suggest alcohol consumption, exposure to pesticides, pollution generated by open landfills, and ethnicity as possible explanatory factors.

Discussion/conclusion

Our study provided for the first time an extensive description of geographical disparities in cancer incidence in Guadeloupe, in a region where socioeconomic and environmental issues are major concerns. Although the identification of underlying factors was out of the scope of the present study, we highlighted areas of special interest and put forward some hypotheses that warrant to be further investigated in more in-depth analyses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09886-6.

Recently approved treatment options for patients with metastatic triple-negative and HER2-neu-positive breast cancer

Breast cancer (BC) is the most common cancer affecting women worldwide. In 2021, the estimated number of new breast cancer cases was 281 550 and about 43 500 women died from metastatic breast cancer (mBC). For women aged 20-59 years, mBC remains the leading cause of cancer death and is, therefore, an important public health concern. Only 5% of women initially present with metastatic disease. Approximately 20% of patients presenting with local or locoregional disease progress to mBC despite adjuvant therapy. Inspite of all the medicosurgical advancements, the overall prognosis for patients diagnosed with mBC remains poor, with median overall survival of approximately 31 months, although this varies based on tumor biology. In recent years, there has been significant progress in developing immunotargeted therapies such as antihuman epidermal growth factor receptor 2 (anti-HER2) or check point inhibitors that confirmed to have dramatically improve the prognosis of mBC, a historically unfavorable disease subset. Even with the major progress that has been made in understanding the biology of BC, challenges such as resistance frequency to therapies, unknown efficacy, concerns for safety of drug combination and toxicities still remain high. Therefore, a new targeted and more selective treatment approaches are the need of the hour. In this review, we aim to outline the most recently approved medications in treatment of Her2-positive and triple-negative breast cancers.

Breast cancer incidence trends in Asian women aged 20 or older as compared to other ethnic women in the United States from 2000 to 2018 by time period, age and tumor stage

BACKGROUND

After new cancer data are released in April 2021, it is important to update the incidence trend in breast cancer from 2000 to 2018 and focus on ethnic disparities in the risk of developing breast cancer.

METHODS

We identified 1129,564 women who were diagnosed with incident breast cancer at age ≥ 20 in 2000-2018 from 18 SEER (Surveillance, Epidemiology, and End Results) registries. We utilized the SEER*Stat software to calculate age-adjusted incidence rates.

RESULTS

Overall age-adjusted incidence rate of breast cancer was the highest in non-Hispanic white (NHW) women (190.4 cases per 100,000 women), followed by NH-black (NHB) (178.4), Asian/Pacific-Islanders (API) (141.3), Hispanic (133.3) and American-Indians/Alaska-Native (AIAN) women (128.8). Annual percentage change (APC) from 2000 to 2018 showed that annual increase was statistically significant for API (APC: 1.0, 95% CI: 0.8-1.3), NHB (APC: 0.5, 0.2-0.7), AIAN (1.6, 1.1-2.2), and Hispanic women (0.4, 0.2-0.7), but annual percentage of incidence did not significantly decrease for NHW (-0.1, -0.4 to -0.1). Incidence rates of hormone-receptor positive breast cancer increased from 2000 to 2018 in all ethnic women, while incidence rates of hormone-receptor negative breast cancer decreased. NHW and NHB women had a significantly higher risk of having breast cancer than API women. In 2012-2018, the risks of having local stage and distant stage breast cancer for NHW (1.31, 1.29-1.33 and 1.19, 1.16-1.21) and NHB (1.09, 1.07-1.11 and 1.31, 1.28-1.35) women were significantly higher than that of API women.

CONCLUSIONS

The incidence of hormone-receptor positive breast cancer increased in all ethnic women from 2000 to 2018 while the incidence of hormone-receptor negative breast cancer decreased. There were still substantial racial disparities in breast cancer incidences.

Recent Changes in the Patterns of Breast Cancer as a Proportion of All Deaths According to Race and Ethnicity

BACKGROUND

Recent reports suggest that racial differences in breast cancer incidence rates have decreased. We examined whether these findings apply to breast cancer mortality while considering age, period, and cohort influences on both absolute and relative measures of breast cancer mortality.

METHODS

Using publicly available datasets (CDC WONDER, Human Mortality Database), we developed an age-period-cohort model of breast cancer mortality and breast cancer deaths as a proportion of all deaths during 1968-2019 among all women and by 5 race/ethnicity groups with sufficient numbers for estimation: Hispanic (all races), American Indian/Alaska Native and Asian/Pacific Islanders (regardless of ethnicity), non-Hispanic Black, and non-Hispanic White.

RESULTS

Initially increasing after 1968, age-adjusted breast cancer mortality rates have decreased among all racial/ethnic groups since 1988. The age-adjusted percent of all deaths due to breast cancer also has been declining for non-Hispanic White women since about 1990 while increasing or holding steady for other race/ethnic groups. In 2019, the age-adjusted percent of deaths due to breast cancer for women was highest for Asian/Pacific Islanders (5.6%) followed by non-Hispanic Black (4.5%), Hispanic (4.4%), non-Hispanic White (4.1%), and American Indian/Alaska Native women (2.6%).

CONCLUSIONS

Breast cancer mortality disparities are now greater on both relative and absolute scales for non-Hispanic Black women, and using the relative scale for Asian/Pacific Islander and Hispanic women, compared with non-Hispanic White women for the first time in 50 years.

Decreasing Incidence of Estrogen Receptor-Negative Breast Cancer in the United States: Trends by Race and Region

Background

Incidence of estrogen receptor (ER)-negative breast cancer, an aggressive subtype, is highest in US African American women and in Southern residents but has decreased overall since 1992. We assessed whether ER-negative breast cancer is decreasing in all age groups and cancer registries among non-Hispanic White (NHW), non-Hispanic Black (NHB), and Hispanic White (HW) women.

Methods

We analyzed 17 Surveillance, Epidemiology, and End-Results (SEER) Program registries (12 for 1992-2016; 5 for 2000-2016) to assess NHW, NHB, and HW trends by ER status and age group (30-39 years, 40-49 years, 50-69 years, 70-84 years). We used hierarchical age-period-cohort models that account for sparse data, which improve estimates to quantify between-registry heterogeneity in mean incidence rates and age-adjusted trends vs SEER overall.

Results

Overall, ER-negative incidence was highest in NHB, then NHW and HW women, and decreased from 1992-2016 in each age group and racial or ethnic group. The greatest decrease was for HW women aged 40-49 years, with an annual percent change of –3.5%/y (95% credible interval = −4.4%, −2.7%) averaged over registries. The trend heterogeneity was statistically significant in every race or ethnic and age group. Furthermore, the incidence relative risks by race or ethnicity compared with the race-specific SEER average were also statistically significantly heterogeneous across the majority of registries and age groups (62 of 68 strata). The greatest heterogeneity was seen in HW women, followed by NHB women, and the least in NHW women.

Conclusions

Decreasing ER-negative breast cancer incidence differs meaningfully by US region and age among NHB and HW women. Analytical studies including minority women from higher and lower incidence areas may provide insights into breast cancer racial disparities.

A Systematic Comparison of Overall Survival Between Men and Women With Triple Negative Breast Cancer

INTRODUCTION

Triple-negative breast cancer (TNBC) in men is very rare. The clinical characteristics, prognostic factors, and overall survival of men with TNBC have not been characterized.

METHODS

The study population consisted of men and women with a diagnosis of stage I-III TNBC between 2010 and 2016 in the National Cancer Database. Baseline demographic and tumor characteristics between men and women were compared using Pearson's Chi-Square test for categorical variables and Mann-Whitney U test for continuous variables. Kaplan-Meier and multivariate Cox proportional hazards regression model was used to compare survival and identify prognostic factors.

RESULTS

A total of 311 men and 95,406 women with TNBC were included in the final analysis. The 3-year and 5-year overall survival was 74.8% and 68.8% in men, while it was 83.2% and 74.8% in women, respectively. In multivariate analysis, men were found to have a significantly worse overall survival compared to women (HR, 1.49, 95% CI, 1.19-1.86, P= .01). Older age at diagnosis, higher TNM stage, undergoing mastectomy and not undergoing chemotherapy or radiation were identified as independent negative prognostic factors in men with TNBC.

CONCLUSION

In one of the largest studies of men with TNBC, men were noted to have a poorer overall survival compared to women, despite adjusting for usual prognostic factors. Further research into differences in tumor biology, treatment patterns and compliance with therapy between men and women are needed to understand the underlying etiologies for the survival difference in TNBC.

A Critical Theoretical Approach to Cancer Disparities: Breast Cancer and the Social Determinants of Health

Breast cancer is the most commonly experienced cancer among women. Its high rates of incidence and survival mean that a number of women will live it for periods of their lifetimes. Group differences in breast cancer incidence and mortality occur by race and ethnicity. For example, while white women are slightly more likely to be diagnosed with breast cancer, Black women are 40% more likely to die from the disease. In this article, rather than focusing the discussion on individual-level factors like health behaviors that have the potential to blame Black women and those living in poverty for their conditions, we view breast cancer disparities through the lens of Critical Race Theory, taking a historical perspective. This allows us to delve beyond individual risk factors to explore social determinants of breast cancer disparities at the population level, paying special attention to the myriad ways in which social factors, notably views of race and discriminatory public policies, over time have contributed to the disproportionate breast cancer mortality experienced by Black women. We suggest ways of addressing breast cancer disparities, including methods of training healthcare professionals and public policy directions, that include rather than marginalize Black and lower socioeconomic status women.

Factors associated with breast cancer recurrence and survival at Sangre Grande Hospital, Trinidad

PURPOSE

The aim of this study is to determine the demographic, pathological, and treatment-related factors that predict recurrence and survival in a Trinidadian cohort of breast cancer patients.

METHODS

The inclusion criteria for this study were female, over 18 years, and with a primary breast cancer diagnosis confirmed by a biopsy report occurring between 2010 and 2015 at Sangre Grande Hospital, Trinidad. Univariate associations with 5-year recurrence-free survival and 5-year overall survival were calculated using the Kaplan-Meier method for categorical variables and Cox Proportional Hazards for continuous variables. A multivariate model for prediction of recurrence and survival was determined using Cox regression.

RESULTS

For the period 2010-2015, 202 records were abstracted. Five-year overall survival and recurrence-free survival rates were found to be 74.3% and 56.4%, respectively. Median times from first suspicious finding to date of biopsy report, date of surgery, and date of chemotherapy were 63 days, 125 days, and 189 days, respectively. In the univariate analysis, age (p = 0.038), stage (p < 0.001), recurrence (p = 0.035), surgery (p = 0.016), ER (p < 0.001) status, PR status (p < 0.001), and subtype (p < 0.001) were significantly associated with survival. Additionally, stage (p = 0.004), N score (p = 0.002), ER (p = 0.028) status, PR (p = 0.018) status, and subtype (p = 0.025) were significantly associated with recurrence. In the Cox multivariate model, Stage 4 was a significant predictor of survival (HR 6.77, 95% CI [0.09-2.49], p = 0.047) and N3 score was a significant predictor of recurrence (HR 4.47, 95% CI [1.29-15.54], p = 0.018).

CONCLUSION

This study reports a 5-year breast cancer survival rate of 74.3%, and a recurrence-free survival rate of 56.4% in Trinidad for the period 2010-2015.

Searching beyond the Lamppost to Reduce Breast Cancer Disparities

Racial and ethnic differences in breast cancer occur by race/ethnicity in both incidence and mortality rates. Women of lower socioeconomic status likewise have poorer outcomes. When race alone is considered, incidence rates in the United States are highest among White women (130.8 per 100,000), with Black women close behind (126.7 per 100,000). Incidence is lowest among Asian/Pacific Islander women, at 93.2 per 100,000. Mortality differences are more pronounced, with Black women 40% more likely to die from breast cancer than White women (28.4 per 100,000 and 20.3 per 100,000, respectively). Mortality rates for Asian/Pacific Islander women (11.5 per 100,000) are far lower than for Black and White women. When age is considered, additional differences between Black and White women appear, in part accounted for by types of breast cancer experienced. Women of other racial/ethnic groups and socioeconomic status have received less scientific attention. In this article, we provide a brief overview of the evidence for social determinants of breast cancer and argue that the current reliance on race over racism and ethnicity contributes to our inability to eliminate breast cancer disparities in the United States and elsewhere in the world. We suggest alternatives to the current approach to research in breast cancer disparities.

Breast Cancer Incidence Trends by Estrogen Receptor Status Among Asian American Ethnic Groups, 1990-2014

Background

Westernization and etiologic heterogeneity may play a role in the rising breast cancer incidence in Asian American (AA) women. We report breast cancer incidence in Asian-origin populations.

Methods

Using a specialized Surveillance, Epidemiology, and End Results-9 Plus API Database (1990-2014), we analyzed breast cancer incidence overall, by estrogen receptor (ER) status, and age group among non-Hispanic white (NHW) and AA women. We used age-period-cohort models to assess time trends and quantify heterogeneity by ER status, race and ethnicity, and age.

Results

Overall, breast cancer incidence increased for most AA ethnicities (Filipina: estimated annual percentage change [EAPC] = 0.96%/year, 95% confidence interval [CI] = 0.61% to 1.32%; South Asian: EAPC = 1.68%/year, 95% CI = 0.24% to 3.13%; Chinese: EAPC = 0.65%/year, 95% CI = 0.03% to 1.27%; Korean: EAPC = 2.55%/year, 95% CI = 0.13% to 5.02%; and Vietnamese women: EAPC = 0.88%/year, 95% CI = 0.37% to 1.38%); rates did not change for NHW (EAPC = -0.2%/year, 95% CI = -0.73% to 0.33%) or Japanese women (EAPC = 0.22%/year, 95% CI = -1.26% to 1.72%). For most AA ethnicities, ER-positive rates statistically significantly increased, whereas ER-negative rates statistically significantly decreased. Among older women, ER-positive rates were stable for NHW and Japanese women. ER-negative rates decreased fastest in NHW and Japanese women among both age groups.

Conclusions

Increasing ER-positive incidence is driving an increase overall for most AA women despite declining ER-negative incidence. The similar trends in NHW and Japanese women (vs other AA ethnic groups) highlight the need to better understand the influences of westernization and other etiologic factors on breast cancer incidence patterns in AA women. Heterogeneous trends among AA ethnicities underscore the importance of disaggregating AA data and studying how breast cancer differentially affects the growing populations of diverse AA ethnic groups.

Inflammation markers on benign breast biopsy are associated with risk of invasive breast cancer in African American women

PURPOSE

Markers of inflammation, including crown-like structures of the breast (CLS-B) and infiltrating lymphocytes (IL), have been identified in breast tissue and associated with increased risk of breast cancer (BrCa), however most of this work has been performed in primarily non-Hispanic white women. Here, we examined whether CLS-B and IL are associated with invasive BrCa in African American (AA) women.

METHODS

We assessed breast biopsies from three 5-year age-matched groups: BrCa-free AA women (50 Volunteer) from the Komen Normal Tissue Bank (KTB) and AA women with a clinically-indicated biopsy diagnosed with benign breast disease (BBD) from our Detroit cohort who developed BrCa (55 BBD-cancer) or did not develop BrCa (47 BBD only, year of biopsy matched to BBD-cancer). Mean adipocyte diameter and total adipose area were estimated from digital images using the Adiposoft plugin from ImageJ. Associations between CLS-B, IL, and BrCa among KTB and Detroit biopsies were assessed using multivariable multinomial and conditional logistic regression models.

RESULTS

Among all biopsies, Volunteer and BBD only biopsies did not harbor CLS-B or IL at significantly different rates after adjusting for logarithm of adipocyte area, adipocyte diameter, and BMI. Among clinically-indicated BBD biopsies, BBD-cancer biopsies were more likely to exhibit CLS-B (odds ratio (OR) = 3.36, 95% Confidence Interval (CI): 1.33-8.48) or IL (OR = 4.95, 95% CI 1.76-13.9) than BBD only biopsies after adjusting for total adipocyte area, adipocyte diameter, proliferative disease, and BMI.

CONCLUSIONS

CLS-B and IL may serve as histological markers of BrCa risk in benign breast biopsies from AA women.

Disparities in mortality-to-incidence ratios by race/ethnicity for female breast cancer in New York City, 2002-2016

Background

Racial disparities in New York City (NYC) breast cancer incidence and mortality rates have previously been demonstrated. Disease stage at diagnosis and mortality‐to‐incidence ratio (MIR) may present better measures of differences in screening and treatment access. Racial/ethnic trends in NYC MIR have not previously been assessed.

Methods

Mammogram rates were compared using the NYC Community Health Survey, 2002‐2014. Breast cancer diagnosis, stage, and mortality were from the New York State Cancer Registry, 2000‐2016. Primary outcomes were MIR, the ratio of age‐adjusted mortality to incidence rates, and stage at diagnosis. Joinpoint regression analysis identified significant trends.

Results

Mammogram rates in 2002‐2014 among Black and Latina women ages 40 and older (79.9% and 78.4%, respectively) were stable and higher than among White (73.6%) and Asian/Pacific‐Islander women (70.4%) (P < .0001). There were 82 733 incident cases of breast cancer and 16 225 deaths in 2000‐2016. White women had the highest incidence, however, rates among Black, Latina, and Asian/Pacific Islander women significantly increased. Black and Latina women presented with local disease (Stage I) less frequently (53.2%, 57.6%, respectively) than White (62.5%) and Asian/Pacific‐Islander women (63.0%). Black women presented with distant disease (Stage IV) more frequently than all other groups (Black 8.7%, Latina 5.8%, White 6.0%, and Asian 4.2%). Black women had the highest breast cancer mortality rate and MIR (Black 0.25, Latina 0.18, White 0.17, and Asian women 0.11).

Conclusions

More advanced disease at diagnosis coupled with a slower decrease in breast cancer mortality among Black and Latina women may partially explain persistent disparities in MIR especially prominent among Black women. Assessment of racial/ethnic differences in screening quality and access to high‐quality treatment may help identify areas for targeted interventions to improve equity in breast cancer outcomes.

Breast Cancer in San Francisco: Disentangling Disparities at the Neighborhood Level

BACKGROUND

This study uses a novel geographic approach to summarize the distribution of breast cancer in San Francisco and aims to identify the neighborhoods and racial/ethnic groups that are disproportionately affected by this disease.

METHODS

Nine geographic groupings were newly defined on the basis of racial/ethnic composition and neighborhood socioeconomic status. Distribution of breast cancer cases from the Greater Bay Area Cancer Registry in these zones were examined. Multivariable logistic regression models were used to determine neighborhood associations with stage IIB⁺ breast cancer at diagnosis. Cox proportional hazards regression was used to estimate the hazard ratios for all-cause and breast cancer-specific mortality.

RESULTS

A total of 5,595 invasive primary breast cancers were diagnosed between January 1, 2006 and December 31, 2015. We found neighborhood and racial/ethnic differences in stage of diagnosis, molecular subtype, survival, and mortality. Patients in the Southeast (Bayview/Hunter's Point) and Northeast (Downtown, Civic Center, Chinatown, Nob Hill, Western Addition) areas were more likely to have stage IIB⁺ breast cancer at diagnosis, and those in the East (North Beach, Financial District, South of Market, Mission Bay, Potrero Hill) and Southeast were more likely to be diagnosed with triple-negative breast cancers (TNBC). Compared with other racial/ethnic groups, Blacks/African Americans (B/AA) experienced the greatest disparities in breast cancer-related outcomes across geographic areas.

CONCLUSIONS

San Francisco neighborhoods with lower socioeconomic status and larger minority populations experience worse breast cancer outcomes.

IMPACT

Our findings, which reveal breast cancer disparities at sub-county geographic levels, have implications for population-level health interventions.

Differences in Genome-wide DNA Methylation Profiles in Breast Milk by Race and Lactation Duration

Black women in the United States are disproportionately affected by early-onset, triple-negative breast cancer. DNA methylation has shown differences by race in healthy and tumor breast tissues. We examined associations between genome-wide DNA methylation levels in breast milk and breast cancer risk factors, including race, to explain how this reproductive stage influences a woman's risk for, and potentially contributes to racial disparities in, breast cancer. Breast milk samples and demographic, behavioral, and reproductive data, were obtained from cancer-free, uniparous, and lactating U.S. black (n = 57) and white (n = 82) women, ages 19-44. Genome-wide DNA methylation analysis was performed on extracted breast milk DNA using the Infinium HumanMethylation450 BeadChip. Statistically significant associations between breast cancer risk factors and DNA methylation beta values, adjusting for potential confounders, were determined using linear regression followed by Bonferroni Correction (P < 1.63 × 10^-7). Epigenetic analysis in breast milk revealed statistically significant associations with race and lactation duration. Of the 284 CpG sites associated with race, 242 were hypermethylated in black women. All 227 CpG sites associated with lactation duration were hypomethylated in women who lactated longer. Ingenuity Pathway Analysis of differentially methylated promoter region CpGs by race and lactation duration revealed enrichment for networks implicated in carcinogenesis. Associations between DNA methylation and lactation duration may offer insight on its role in lowering breast cancer risk. Epigenetic associations with race may mediate social, behavioral, or other factors related to breast cancer and may provide insight into potential mechanisms underlying racial disparities in breast cancer incidence.