Racial disparities in treatment and outcomes between non-Hispanic Black and non-Hispanic White women with nonmetastatic inflammatory breast cancer.

PURPOSE: The incidence rate of inflammatory breast cancer (IBC) is higher among non-Hispanic Black (NHB) than non-Hispanic White (NHW) women. We examined the differences in treatment and outcomes between NHB and NHW women with IBC, accounting for demographic, clinicopathological, and socioeconomic factors. METHODS: We collected data from the Surveillance, Epidemiology, and End Results database for NHB and NHW women with IBC diagnosed between 2010-2016. We analyzed the odds of receiving chemotherapy, radiation, and surgery between NHB and NHW women. We evaluated overall survival (OS) with Kaplan-Meier methods and Cox proportional hazards methods. Competing risk analysis was used to compare the risk of breast cancer death between NHB and NHW women. We also evaluated the magnitude of survival disparities within the strata of demographic, socioeconomic, and treatment factors. RESULTS: Among 1,652 NHW and 371 NHB women with IBC, the odds of receiving chemotherapy, surgery, and radiation were similar for NHB and NHW. After 39-month follow-up, the median OS was 40 and 81 months for NHB and NHW, respectively (p < 0.0001). The risk of breast cancer death was higher for NHB than NHW women (5-year risk of breast cancer death, 51% vs. 35%, p < 0.0001). CONCLUSION: After adjustment for demographic, clinicopathological, and socioeconomic factors; NHB women with IBC had similar odds of receiving surgery, chemotherapy, and radiation therapy, but were more likely to die of the disease compared to their NHW counterparts. Our findings suggest the presence of masked tumor biology, treatment, or socioeconomic factors associated with race that can lead to worse IBC outcomes.

Breast tumor tissue inflammation but not lobular involution is associated with survival among breast cancer patients in the Multiethnic Cohort.

BACKGROUND: This study investigated the association of breast lobular involution status and three inflammatory markers as predictors of survival among breast cancer patients in the Multiethnic Cohort. METHODS: Lobular involution was evaluated in tissue sections of normal breast tissue and COX-2, TNF-α, and TGF-ß proteins were assessed by immunohistochemistry in tumor microarrays. A summary score added the expression levels of the three markers. Cox regression was applied to estimate hazard ratios (HRs) and 95 % confidence intervals (CI) with age as the time metric and adjustment for factors known to affect mortality. RESULTS: Among 254 women (mean age = 61.7 ± 8.7 years) with pathologic blocks and follow-up information, 54 all-cause and 10 breast cancer-specific deaths were identified after a mean follow-up time of 16.0 ± 3.1 years. For 214 participants, an inflammatory score was available and 157 women had information on lobular involution. Lobular involution was not significantly associated with survival. Expression of both COX-2 and TNF-α were significant predictors of lower survival (p = 0.02 and 0.04), while the association for TGF-ß was weaker (p = 0.09). When combined into one overall inflammation score, both intermediate (HR = 2.72; 95 % CI 0.90-8.28) and high (HR = 4.21; 95 % CI 1.51-11.8) scores were associated with higher mortality but only the latter was statistically significant. No significant association with breast cancer-specific mortality was detected. CONCLUSIONS: These results suggest that strong expression of inflammatory markers in breast tissue predicts a poorer prognosis possibly due to a system-wide state of chronic inflammation.

Racial/ethnic disparities in inflammatory breast cancer survival in the Michigan Cancer Surveillance Program.

PURPOSE: While racial disparities in inflammatory breast cancer (IBC) incidence are fairly well documented, with black women having significantly higher rates compared to white women; less is known about whether IBC prognosis differs by race/ethnicity. Therefore, the objective of this study was to assess racial/ethnic disparities in survival among women diagnosed with IBC in the Michigan Cancer Surveillance Program (MCSP) from 1998 to 2014. METHODS: We examined the frequency and percentage of breast cancer cases coded to the various IBC codes in the MCSP registry over the study period. We used age-adjusted and multivariable Cox Proportional hazard regression models to estimate hazard ratios (HR) and 95% confidence intervals (CI) for associations of race/ethnicity with all-cause mortality. RESULTS: Using a comprehensive case definition of IBC, 1324 IBC patients were identified from women diagnosed with invasive breast cancer in the MCSP [Non-Hispanic Black (NHB) = 227; Non-Hispanic White (NHW) = 984; Hispanic = 86; other = 27]. The percentage of all breast cancer cases defined as IBC in the MCSP registry differs considerably across registry codes from 0.02 to 1.1%. We observed significantly higher risk of death among NHB compared with NHW [HR (95% CI), 1.21 (1.01-1.45)], while no significant survival differences were observed between NHW and Hispanics or other racial/ethnic minorities. CONCLUSIONS: A comprehensive case definition should be utilized to avoid underestimation of IBC and to better understand this aggressive disease. Further research is needed to identify underlying causes and develop effective interventions to reduce IBC survival disparities between NHB and NHW women.

Racial/ethnic differences in breast cancer survival by inflammatory status and hormonal receptor status: an analysis of the Surveillance, Epidemiology, and End Results data.

BACKGROUND: Compared to non-inflammatory breast cancer (non-IBC), inflammatory breast cancer (IBC) has less favorable survival and is more likely to be estrogen receptor (ER) and progesterone receptor (PR) negative. ER-/PR- tumors, regardless of histology, have less favorable survival. While black women are more likely to have IBC and ER-/PR- tumors than white women, it is unclear whether the racial disparity in survival is explained by these factors. The objective of this study was to assess racial/ethnic differences in breast cancer survival by inflammatory status and hormone receptor status. METHODS: This study examined breast cancer mortality among non-Hispanic white (NHW), Hispanic white, black, and Asian/Pacific Islander (API) women diagnosed between 1990 and 2004 using the National Cancer Institute's Surveillance, Epidemiology, and End Results data. Kaplan-Meier survival curves and Cox proportional hazard ratios (HRs) assessed the relationship between race/ethnicity and survival. RESULTS: Black women had significantly poorer survival than NHW women regardless of inflammatory status and hormone receptor status. Compared to NHWs, the HRs for black women were 1.32 (95 % confidence interval (CI) 1.21-1.44), 1.43 (95 % CI 1.20-1.69), and 1.30 (95 % CI 1.16-1.47) for IBC, IBC with ER+/PR+, and with ER-/PR-, respectively. Similar HRs were found for non-IBC, non-IBC with ER+/PR-, and non-IBC with ER-/PR-. API women had significantly better survival than NHW women regardless of inflammatory status and hormone receptor status. CONCLUSION: Compared to NHW women, black women had poorer survival regardless of inflammatory status and hormone receptor status and API women had better survival. These results suggest that factors other than inflammatory status and hormone receptor status may play a role in racial/ethnic disparities in breast cancer survival.

Association of inflammatory and noninflammatory breast cancer with socioeconomic characteristics in the Surveillance, Epidemiology, and End Results database, 2000-2007.

BACKGROUND: Inflammatory breast cancer (IBC) is a rare and highly aggressive form of primary breast cancer. Little is known about the risk factors for IBC, specifically the association with socioeconomic position (SEP). METHODS: The association between breast cancer type (IBC vs. non-IBC) with county-level SEP in the Surveillance, Epidemiology, and End Results database for cases diagnosed from 2000 to 2007 was examined. County-level SEP characteristics included metropolitan versus non-metropolitan residence, percentage below the poverty level, percentage less than high-school graduate, and an index combining the poverty and high-school variables. IBC and non-IBC age-adjusted incidence rates were calculated, stratified on SEP and race/ethnicity. The odds of IBC versus non-IBC given a particular SEP characteristic, adjusting for age and race/ethnicity, was examined through fitting of hierarchical logistic regression models (HLM). RESULTS: Incidence rates for IBC generally increased as SEP decreased, whereas the opposite was found for non-IBC. HLM results showed that low SEP is associated with higher odds of IBC: highest (≥ 20%) versus lowest (<10%) persons below the poverty level [OR (95% confidence interval, CI) = 1.25 (1.09-1.43)]; highest (>28.76%) versus lowest (≤ 15.99%) persons less than high-school graduate [OR (95% CI) = 1.25 (1.10-1.42)]; and low SEP as measured by poverty-high school index versus high SEP [OR (95% CI)= 1.26 (1.11-1.44)]. CONCLUSION: Overall breast cancer has been found to be positively associated with SEP, whereas in this analysis, IBC was associated with decreasing SEP. IMPACT: Studies focused on understanding the disparity in IBC incidence, as well as interventions to eliminate these differences are needed.

What can we learn from the age- and race/ethnicity- specific rates of inflammatory breast carcinoma?

Inflammatory Breast Carcinoma (IBC), the most aggressive type of breast tumor with unique clinicopathological presentation, is hypothesized to have distinct etiology with a socioeconomic status (SES) component. Using the Surveillance, Epidemiology and End Results (SEER) Program data for 2004-2007, we compare incidence rates of IBC to non-inflammatory locally advanced breast cancer (LABC) among racial/ethnic groups with different SES. The analysis includes women 20-84 years of age. To examine evidence for the distinct etiology of IBC, we analyzed age-distribution patterns of IBC and non-inflammatory LABC, using a mathematical carcinogenesis model. Based on the Collaborative Staging Extension codes, 2,942 incident IBC cases (codes 71 and 73) and 5,721 non-inflammatory LABC cases (codes 40-62) were identified during the four-year study period. Age-adjusted rates of IBC among non-Hispanic White and Hispanic women were similar (2.5/100,000 in both groups). Similar rates were also found in non-inflammatory LABC in these two groups (4.8/100,000 and 4.2/100,000, respectively). In African-American women, the IBC (3.91/100,000) and non-inflammatory LABC (8.47/100,000) rates were greater compared with other ethnic/racial sub-groups. However, the ratio of rates of IBC/non-inflammatory LABC was similar among all the racial/ethnic groups, suggesting that African-American women are susceptible to aggressive breast tumors in general but not specifically to IBC. The mathematical model successfully predicted the observed age-specific rates of both examined breast tumors and revealed distinct patterns. IBC rates increased until age 65 and then slightly decreased, whereas non-inflammatory LABC rates steadily increased throughout the entire age interval. The number of critical transition carcinogenesis stages (m-stages) predicted by the model were 6.3 and 8.5 for IBC and non-inflammatory LABC, respectively, supporting different etiologies of these breast tumors.

Treatment adherence and outcome in women with inflammatory breast cancer: does race matter?

BACKGROUND: The authors compared treatment adherence rates and outcome in Caucasian and African American patients with inflammatory breast cancer (IBC). METHODS: The records of 55 (25 Caucasian and 30 African American) IBC patients treated with curative intent from 1995 to 2009 were reviewed. All patients received neoadjuvant doxorubicin (Adriamycin) and/or taxane-based chemotherapy, and mastectomy with or without radiotherapy. The median follow-up period for Caucasian and African American patients was similar (39.5 months and 36.1 months, respectively). RESULTS: There was no difference between races in median age, tumor size, grade, and receptor status at diagnosis. The number of patients who completed neoadjuvant chemotherapy, surgery, and radiotherapy did not differ by race (84% of Caucasians vs 86.7% of African Americans) nor did the median length of time to complete trimodality treatment (263 [range, 207-422] days for Caucasians vs 262 [range, 165-371] days for African Americans). There was a trend toward slightly higher pathological complete response rates in Caucasian than African American women (20% in Caucasians vs 6.7% in African Americans, P = .23). Despite slightly better response rates to neoadjuvant chemotherapy, Caucasian patients did not have higher 3-year local control rates (70% in Caucasians vs 64% in African Americans, P = .73). However, there was a trend toward higher 3-year overall survival in Caucasian versus African American patients (73% in Caucasians vs 55% in African Americans, P = .09) and higher distant metastasis-free survival (60% in Caucasians vs 40% in African Americans, P = .19). CONCLUSIONS: This study is among the largest to examine patients with IBC by race. Being Caucasian or African American did not appear to impact treatment adherence. However, African American patients tended to have poorer response to standard treatment and worse outcome than Caucasian patients.