Racial disparities in receipt of curative surgery for early-stage non–small cell lung cancer in Florida

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Background: Lung cancer is the leading cause of cancer death in the United States. Receipt of curative-intent surgery for early-stage non–small cell lung cancer (NSCLC) is associated with disparities in race and socioeconomic status, which is subsequently related to the outcome of NSCLC. This study aimed to examine the racial disparity in receipt of curative-intent surgery among early-stage NSCLC in Florida. Methods: A total of 80,458 patients with early-stage NSCLC diagnosed from 2005 to 2017 were identified from the statewide cancer registry, Florida Cancer Data System (FCDS). Percentage of patients receiving curative-intent surgery was calculated for each race/ethnicity. FCDS data was linked to discharge data containing comorbidity information for each lung cancer patient. There was a 94% match between FCDS and discharge data. Multivariable logistic regression was used to determine the impact of race on receipt of curative-intent surgery for early-stage NSCLC. Results: Among 80,458 patients with early-stage NSCLC, 66,761 (83.0%) were White, 5,503 (6.8%) were Black and 6,981 (8.7%) were Hispanic. Of note, 69.5% Hispanic patients lived in South Florida. Asian patients (59.9%) had the highest proportion of curative surgery, followed by Hispanics (57.8%), Whites (52.9%) and Blacks (42.6%). In the multivariable model, patients with Charlson Comorbidity Index (CCI)≥3 had 34% lower odds of having curative surgery (OR, 0.66; 95% CI, 0.62 to 0.7) compared to patients who did not have any comorbidity (CCI=0). Highest poverty levels had 27% lower odds of receiving curative-intent surgery compared to lowest (OR: 0.73; 95% CI: 0.68 to 0.78). After adjusting for sociodemographic factors (i.e., age, sex, race, insurance, region) and clinical factors (i.e., histology, AJCC stage, CCI, smoking status), Blacks had 27% lower odds of receiving curative-intent surgery (OR, 0.73; 95% CI, 0.68 to 0.79), whereas Hispanics had 22% (OR, 1.22; 95% CI, 1.14 to 1.30) and Asians had 19% (OR, 1.19; 95% CI, 0.98 to 1.46) higher odds than Whites. In the stratified analysis by regions, Blacks had lower odds of receiving curative-intent surgery than Whites in all regions across Florida while Hispanics had higher odds of receiving surgery than Whites only in South Florida (OR, 1.29; 95% CI, 1.18 to 1.41). Conclusions: There are persistent racial disparities in receipt of curative-intent surgery for early-stage NSCLC in Florida. Specifically, Blacks are receiving less curative-intent surgery, despite adjustments for comorbidities, socio-economic status, and insurance. Ethno-regional differences within different regions of Florida are evident with Hispanics surpassing all other races in receipt of curative treatment in heavily Hispanic South Florida.

Elevated breast cancer mortality among highly educated Asian American women

Background

Postmenopausal breast cancer (PMBC) is the most commonly diagnosed and the second leading cause of cancer death among women in the US. Research examining the association between PMBC and education level has been inconsistent; no study in the US has examined how educational level impacts PMBC mortality in Asian American women, a largely immigrant population with above-average educational attainment.

Methods

California Vital Statistics data from 2012–2017 were analyzed to derive age-adjusted mortality rate ratios (MRRs) by education level (associates degree or above referred to as “higher education”, high school, less than high school) and race [Non-Hispanic White (NHW), Asian/Pacific Islander (Asian), and its two largest subpopulations: Chinese and Filipino] from negative binomial regression models.

Results

PMBC mortality for both NHWs and Asians was greater among women with higher education compared to those who did not complete high school: NHWs had 22% higher PMBC mortality (MRR 1.22; 95% CI: 1.14–1.31) and Asians had 2.6 times greater PMBC mortality (MRR 2.64; 95% CI: 2.32–3.00) than their counterparts who did not complete high school. Asians in the lowest education level had 70% lower mortality than NHWs (MRR 0.30; 95% CI: 0.27–0.34). This mortality advantage among Asians was greatly reduced to only 27% lower among the highest educated (MRR 0.73; 95% CI: 0.68–0.78). For higher educated Filipina women, no mortality advantage was evident compared to NHWs (MRR 0.96; 95% CI: 0.88–1.05).

Conclusion

PMBC mortality for higher educated Asian women is elevated in comparison to their counterparts with less education. Given that PMBC survival is greater among those with higher education, our findings strongly suggest an excess in the incidence of PMBC (more than double) among higher educated Asian women; this warrants more research into potentially modifiable causes of PMBC in this burgeoning population.

Survival for endometrial cancer as a second primary malignancy

BACKGROUND

Endometrial cancer (EC) often occurs subsequently to a primary cancer arising from a different site. However, little is known regarding the survival experience of EC as a second primary (ECSP) malignancy, specifically in relation to the original primary site and prior treatment.

METHODS

Using Florida's cancer registry, all EC cases (first, second, or higher-order) diagnosed from 2005-2016 were analyzed. Kaplan-Meier methods and Cox Regression were used in a cause-specific survival analysis.

RESULTS

A total of 2879 clinically independent ECSPs and 42,714 first primary ECs were analyzed. The most common first primary sites for ECSPs were breast cancer (BC) (n = 1422) and colorectal cancer (CRC) (n = 359). Five-year cause-specific survival was 84.0% (95% CI: 83.6-84.3) for first primary ECs and 81.8% (95% CI: 80.0-83.4) for ECSPs. After adjusting for age, race/ethnicity, histology, and stage at diagnosis, ECSPs had a lower risk of EC mortality than first primary ECs (hazard ratios [HR] 0.88, 95% CI: 0.79-0.97). ECSPs with a first primary CRC had a higher risk of EC-specific death (HR 1.47, 95% CI: 1.04-2.06) compared to ECSPs that followed BC in multivariable analysis. Finally, women who had chemotherapy for ECSP and preceding BC did not have a higher risk of death (HR 0.80, 95% CI: 0.49-1.31) compared to those who only received chemotherapy for first primary EC.

CONCLUSIONS

ECSPs present a complex clinical profile. ECSP survival is superior to that of first primary EC. However, ECSPs following CRC may constitute a population of interest for their worse prognosis. Chemotherapy for a previous BC does not seem to impact the effectiveness of chemotherapy for ECs.

Abstract IA-09: Liver cancer and differences across Hispanic groups: Importance of disaggregation in understanding cancer disparities

The incidence of hepatocellular carcinoma (HCC) has risen considerably in the US since 1980. The main causes include metabolic disorders (NAFLD, diabetes, obesity, metabolic syndrome), alcohol-related disease (ALD) and hepatitis C and B virus infections (HCV, HBV). Etiology-specific HCC incidence rates by detailed race-ethnicity are needed to improve HCC control and prevention efforts. All HCC cases diagnosed in Florida during 2005-2018 were linked to statewide hospital discharge data to determine etiology. Age-specific and age-adjusted rates were used to assess the intersection between etiology and detailed racial-ethnicities, including non-Hispanic White, non-Hispanic Black and Hispanic groups: Mexican, Cuban, Puerto Rican, Dominican, South, Central American. Of 19,956 HCC cases including 3,660 Hispanics, 87% matched with discharge data. For 2012-2018, HCV was the leading cause of HCC White, Black and Hispanic men (45.4%, 54.7% and 41.0% respectively) followed by NAFLD-related metabolic disorders and ALD. The leading cause of HCC among White and Black women was also HCV (38.3% and 50.2%) while for Hispanic women NAFLD-HCC (46.7%) was the most common form. Puerto Rican men had the highest HCV-HCC rates, 10.2 per 100 000. Metabolic-HCC rates were highest among populations above age 70 and among all Hispanics except Cubans. Mexican men had high rates of ALD-HCC. HCC etiology is associated with specific race/ethnicity. While HCV-related HCC rates are projected to decrease soon, HCC will continue to affect Hispanics disproportionately, based on higher rates of metabolic-HCC and ALD-HCC. Multifaceted approaches for HCC control and prevention are needed.

Citation Format: Paulo S. Pinheiro. Liver cancer and differences across Hispanic groups: Importance of disaggregation in understanding cancer disparities [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr IA-09.

Heterogeneity in head and neck cancer incidence among black populations from Africa, the Caribbean and the USA: Analysis of cancer registry data by the AC3

BACKGROUND

Africa and the Caribbean are projected to have greater increases in Head and neck cancer (HNC) burden in comparison to North America and Europe. The knowledge needed to reinforce prevention in these populations is limited. We compared for the first time, incidence rates of HNC in black populations from African, the Caribbean and USA.

METHODS

Annual age-standardized incidence rates (IR) and 95% confidence intervals (95%CI) per 100,000 were calculated for 2013-2015 using population-based cancer registry data for 14,911 HNC cases from the Caribbean (Barbados, Guadeloupe, Trinidad & Tobago, N = 443), Africa (Kenya, Nigeria, N = 772) and the United States (SEER, Florida, N = 13,696). We compared rates by sub-sites and sex among countries using data from registries with high quality and completeness.

RESULTS

In 2013-2015, compared to other countries, HNC incidence was highest among SEER states (IR: 18.2, 95%CI = 17.6-18.8) among men, and highest in Kenya (IR: 7.5, 95%CI = 6.3-8.7) among women. Nasopharyngeal cancer IR was higher in Kenya for men (IR: 3.1, 95%CI = 2.5-3.7) and women (IR: 1.5, 95%CI = 1.0-1.9). Female oral cavity cancer was also notably higher in Kenya (IR = 3.9, 95%CI = 3.0-4.9). Blacks from SEER states had higher incidence of laryngeal cancer (IR: 5.5, 95%CI = 5.2-5.8) compared to other countries and even Florida blacks (IR: 4.4, 95%CI = 3.9-5.0).

CONCLUSION

We found heterogeneity in IRs for HNC among these diverse black populations; notably, Kenya which had distinctively higher incidence of nasopharyngeal and female oral cavity cancer. Targeted etiological investigations are warranted considering the low consumption of tobacco and alcohol among Kenyan women. Overall, our findings suggest that behavioral and environmental factors are more important determinants of HNC than race.

New insights into the burden of COVID-19 mortality for U.S. Hispanics and Blacks when examined by country/region of origin: An observational study

Background

Florida's diverse population composition includes persons from throughout Latin America and the Caribbean. This facilitated an insightful examination of disparities in 2020 Florida COVID-19 deaths not only among racial/ethnic populations in the aggregate (non-Hispanic White, non-Hispanic Black, Hispanic) but also at the level of country/region of origin.

Methods

Age-adjusted mortality rates (AAMRs) for 2020 Florida COVID-19 deaths were calculated by race, ethnicity, and country/region of origin along with mean age at death, mean number of comorbidities, and percentage of decedents who had not completed secondary education. Regression-derived mortality rate ratios (MRRs) compared death rates for each racial/ethnic/country-of-origin population to non-Hispanic whites.

Findings

The overall AAMR (per 100,000) for 18,342 Florida COVID-19 deaths in 2020 was 55.4, with a much lower AAMR for non-Hispanic Whites (39.3) than for Hispanics (86.8) or Blacks (107.6). Marked differences in AAMRs were observed for specific Black and Hispanic ethnic groups from varied countries/regions of origin. COVID-19 decedents from Mexico and Central America had the highest AAMRs (170.7 and 168.8 per 100,000, respectively), lowest age at death, lowest educational level, and fewest comorbidities. Mean comorbidities were highest for Blacks (all origins) and Cuban Hispanics.

Interpretation

Florida Blacks and Hispanics experienced disproportionately high COVID-19 mortality rates throughout 2020, with notable variability based on country/region of origin. Inequities were particularly pronounced for Hispanic populations from Mexico and Central America. To better understand these heterogeneous COVID-19 mortality trends, more nuanced racial/ethnic analyses and detailed data on social determinants of health are needed.

Funding

Supplemental funding was provided by the Sylvester Comprehensive Cancer Center at University of Miami Miller School of Medicine. Research reported in this publication was also supported by the National Cancer Institute of the National Institutes of Health under Award Number P30CA240139.

Cancer statistics for the US Hispanic/Latino population, 2021

The Hispanic/Latino population is the second largest racial/ethnic group in the continental United States and Hawaii, accounting for 18% (60.6 million) of the total population. An additional 3 million Hispanic Americans live in Puerto Rico. Every 3 years, the American Cancer Society reports on cancer occurrence, risk factors, and screening for Hispanic individuals in the United States using the most recent population-based data. An estimated 176,600 new cancer cases and 46,500 cancer deaths will occur among Hispanic individuals in the continental United States and Hawaii in 2021. Compared to non-Hispanic Whites (NHWs), Hispanic men and women had 25%-30% lower incidence (2014-2018) and mortality (2015-2019) rates for all cancers combined and lower rates for the most common cancers, although this gap is diminishing. For example, the colorectal cancer (CRC) incidence rate ratio for Hispanic compared with NHW individuals narrowed from 0.75 (95% CI, 0.73-0.78) in 1995 to 0.91 (95% CI, 0.89-0.93) in 2018, reflecting delayed declines in CRC rates among Hispanic individuals in part because of slower uptake of screening. In contrast, Hispanic individuals have higher rates of infection-related cancers, including approximately two-fold higher incidence of liver and stomach cancer. Cervical cancer incidence is 32% higher among Hispanic women in the continental US and Hawaii and 78% higher among women in Puerto Rico compared to NHW women, yet is largely preventable through screening. Less access to care may be similarly reflected in the low prevalence of localized-stage breast cancer among Hispanic women, 59% versus 67% among NHW women. Evidence-based strategies for decreasing the cancer burden among the Hispanic population include the use of culturally appropriate lay health advisors and patient navigators and targeted, community-based intervention programs to facilitate access to screening and promote healthy behaviors. In addition, the impact of the COVID-19 pandemic on cancer trends and disparities in the Hispanic population should be closely monitored.

Comparing Age at Cancer Diagnosis between Hispanics and Non-Hispanic Whites in the United States

BACKGROUND

Population age structure may confound the comparison of age at cancer diagnosis across racial/ethnic groups. We compared age at cancer diagnosis for U.S. Hispanics, a population that is younger on average, and non-Hispanic whites (NHW), before and after adjustment for the age structure of the source population.

METHODS

We used Surveillance, Epidemiology, and End Results data from 18 U.S. regions in 2015 for 34 cancer sites to calculate crude and adjusted (using age- and sex-specific weights) mean ages at diagnosis. Differences in age at diagnosis comparing Hispanics to NHWs (δ) were assessed using independent sample t tests.

RESULTS

Crude mean ages at diagnosis were lower among Hispanic males and females for all sites combined and for most cancer sites. After age-adjustment, Hispanic (vs. NHW) males remained younger on average at diagnosis of chronic myeloid leukemia [δ = -6.1; 95% confidence interval (CI), -8.1 to -4.1 years], testicular cancer (δ =-4.7; 95% CI, -5.4 to -4.0), Kaposi sarcoma (δ =-3.6; 95% CI,-6.3 to -0.8), mesothelioma (δ =-3.0; 95% CI,-4.3 to -1.7), and anal cancer (δ =-2.4; 95% CI, -3.9 to -0.8), and older at diagnosis of gallbladder cancer (δ = +3.8; 95% CI, 1.8 to 5.7) and Hodgkin's lymphoma (δ = +7.5; 95% CI, 5.7 to 9.4), and Hispanic (vs. NHW) females remained younger at diagnosis of mesothelioma (δ = -3.7; 95% CI, -6.7 to -0.7) and gallbladder cancer (δ = -3.0; 95% CI, -4.3 to -1.7) and older at diagnosis of skin cancer (δ = +3.8; 95% CI, 3.1 to 4.5), cervical cancer (δ = +4.1; 95% CI, 3.3 to 4.8), and Hodgkin's lymphoma (δ = +7.0; 95% CI, 5.0 to 9.1).

CONCLUSIONS

On average, Hispanics are diagnosed with cancer at younger ages than NHWs; however, for many cancers these differences reflect the younger age structure in Hispanics.

IMPACT

Population age structure should be considered when comparing age at cancer diagnosis across racial/ethnic groups.

GRASP1 ubiquitination regulates AMPA receptor surface expression and synaptic activity in cultured hippocampal neurons

The synaptic expression of glutamate receptors of the α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) type is dynamically controlled by interaction with binding partners and auxiliary proteins. These proteins can be regulated by posttranslational modifications, including ubiquitination. In this work, we investigated the regulation of glutamate receptor interacting protein-associated protein 1 (GRASP1) by ubiquitin-dependent mechanisms and its impact on surface expression and activity of synaptic AMPA receptors. Cotransfection of GFP-ubiquitin decreased myc-GRASP1 protein levels in HEK293T cells, and this effect was inhibited upon transfection of an ubiquitin mutant that cannot be ubiquitinated on Lys48. In addition, transfection of cultured hippocampal neurons with GFP-ubiquitin reduced the dendritic levels of endogenous GRASP1 and decreased the surface expression of GluA1 AMPA receptor subunits, an effect that was partly reversed by cotransfection with GRASP1. Similarly, transfection of hippocampal neurons with GFP-ubiquitin decreased the amplitude of miniature excitatory postsynaptic currents (mEPSCs) mediated by Ca²⁺ -impermeable AMPA receptors, and this effect was abrogated by cotransfection of GRASP1. Together, the results show a role for ubiquitination in the regulation of the postsynaptic protein GRASP1, which has an impact on the surface distribution of AMPA receptors and on their activity at the synapse.

Endometrial Cancer Type 2 Incidence and Survival Disparities Within Subsets of the US Black Population

Introduction

Endometrial cancer type 2 (EC2) carries a worse prognosis compared to EC type 1. EC2 disproportionately affects Black women among whom incidence is higher and survival is poorer compared to Whites. Here we assessed EC2 incidence and survival patterns among US Black ethnic groups: US-born Blacks (UBB), Caribbean-born Blacks (CBB), and Black Hispanics (BH).

Methods

We analyzed population-based data (n=24,387) for the entire states of Florida and New York (2005–2016). Hysterectomy-corrected EC2 incidence rates were computed by racial-ethnic group, and survival disparities were examined using Cox regression adjusting for tumor characteristics, poverty level, and insurance status.

Results

EC2 incidence rates were highest among UBB (24.4 per 100,000), followed by CBB (18.2), Whites (11.1), and Hispanics of all races (10.1). Compared to Whites, the age-adjusted cause-specific survival was worse for non-Hispanic Blacks (aHR: 1.61; 95%CI 1.52–1.71) and Hispanics of all races (aHR:1.09; 95% CI:1.01–1.18). In relation to Whites, survival was worse for non-Hispanic Blacks: UBB (aHR:1.62; 95%CI 1.52–1.74) and CBB (aHR:1.59; 95% CI:1.44–1.76) than for BH (aHR:1.30; 95% CI:1.05–1.61). Surgical resection was associated with a lower risk of death, while carcinosarcoma subtype and advanced stage at diagnosis were associated with a greater risk.

Conclusions

Although higher EC2 incidence and lower survival are observed among all African-descent groups, there are significant intra-racial differences among UBB, CBB, and BH. This heterogeneity in EC2 patterns among Black populations suggests an interplay between genetic and socioenvironmental factors.

Cancer Mortality Disparities among Asian American and Native Hawaiian/Pacific Islander Populations in California

BACKGROUND

Asian American and Native Hawaiian/Pacific Islanders (AANHPI) are the fastest growing minority in the United States. Cancer is the leading cause of death for AANHPIs, despite relatively lower cancer morbidity and mortality. Their recent demographic growth facilitates a detailed identification of AANHPI populations with higher cancer risk.

METHODS

Age-adjusted, sex-stratified, site-specific cancer mortality rates from California for 2012 to 2017 were computed for AANHPI groups: Chinese, Filipino, South Asian, Vietnamese, Korean, Japanese, Southeast Asian (i.e., Cambodian, Hmong, Laotian, Thai), and Native Hawaiian and Other Pacific Islander (NHOPI). Regression-derived mortality rate ratios (MRR) were used to compare each AANHPI group to non-Hispanic whites (NHW).

RESULTS

AANHPI men and women (total 40,740 deaths) had lower all-sites-combined cancer mortality rates (128.3 and 92.4 per 100,000, respectively) than NHWs (185.3 and 140.6) but higher mortality for nasopharynx, stomach, and liver cancers. Among AANHPIs, both NHOPIs and Southeast Asians had the highest overall rates including for colorectal, lung (men only), and cervical cancers; South Asians had the lowest. NHOPI women had 41% higher overall mortality than NHWs (MRR = 1.41; 95% CI, 1.25-1.58), including for breast (MRR = 1.33; 95% CI, 1.08-1.65) and markedly higher for endometrial cancer (MRR = 3.34; 95% CI, 2.53-4.42).

CONCLUSIONS

AANHPI populations present with considerable heterogeneous cancer mortality patterns. Heightened mortality for infection, obesity, and tobacco-related cancers in Southeast Asians and NHOPI populations highlight the need for differentiated priorities and public health interventions among specific AANHPI populations.

IMPACT

Not all AANHPIs have favorable cancer profiles. It is imperative to expand the focus on the currently understudied populations that bear a disproportionate cancer burden.

Transient incubation of cultured hippocampal neurons in the absence of magnesium induces rhythmic and synchronized epileptiform-like activity

Cell culture models are important tools to study epileptogenesis mechanisms. The aim of this work was to characterize the spontaneous and synchronized rhythmic activity developed by cultured hippocampal neurons after transient incubation in zero Mg²⁺ to model Status Epilepticus. Cultured hippocampal neurons were transiently incubated with a Mg²⁺-free solution and the activity of neuronal networks was evaluated using single cell calcium imaging and whole-cell current clamp recordings. Here we report the development of synchronized and spontaneous [Ca²⁺]_i transients in cultured hippocampal neurons immediately after transient incubation in a Mg²⁺-free solution. Spontaneous and synchronous [Ca²⁺]_i oscillations were observed when the cells were then incubated in the presence of Mg²⁺. Functional studies also showed that transient incubation in Mg²⁺-free medium induces neuronal rhythmic burst activity that was prevented by antagonists of glutamate receptors. In conclusion, we report the development of epileptiform-like activity, characterized by spontaneous and synchronized discharges, in cultured hippocampal neurons transiently incubated in the absence of Mg²⁺. This model will allow studying synaptic alterations contributing to the hyperexcitability that underlies the development of seizures and will be useful in pharmacological studies for testing new drugs for the treatment of epilepsy.

Kidney cancer mortality disparities among Hispanics in the US

INTRODUCTION

Kidney cancer incidence is increasing among Hispanics but rate differences by distinct group, such as Cuban, Puerto Rican, and Mexican have not been studied. To fill this knowledge gap, we use mortality data, reflecting fatal kidney cancers, to examine patterns by race-ethnicity, including detailed Hispanic groups, and correlate the mortality rates with each group's prevalence of known kidney cancer risk factors: smoking, obesity, hypertension, diabetes, and chronic kidney disease.

METHODS

We used individual-level death data for California, Florida, and New York (2008-2018), and population prevalence data from the National Health Interview Surveys (2008-2018). Age-adjusted mortality rates (AAMRs) and regression-derived mortality rate ratios (MRRs) were computed. Pearson correlation analyses assessed the extent to which group-specific risk factor prevalence explained variability in observed AAMRs.

RESULTS

US-born Mexican Americans and American Indians had the highest rates and MRRs compared to Whites: 1.44 (95 %CI: 1.35-1.53) and 1.51 (1.38-1.64) for Mexican American men and women, respectively, and 1.54 (95 %CI: 1.25-1.89) and 1.53 (95 %CI: 1.15-2.04) for American Indians. In contrast, non-Mexican Hispanics had lower rates than Whites. Among males, positive correlations between AAMRs and smoking, obesity, and chronic kidney disease prevalence by race-ethnicity were found.

CONCLUSION

Mexican Americans and American Indians are high-risk for fatal kidney cancer. Disparities are only partially attributable to higher smoking and obesity prevalence, and more so among men than women. A shared risk factor profile, as well as possible genetic similarities, may explain their disproportionately higher kidney cancer mortality, but further research is warranted.

Synaptotagmin-7 places dense-core vesicles at the cell membrane to promote Munc13-2- and Ca2+-dependent priming

Synaptotagmins confer calcium-dependence to the exocytosis of secretory vesicles, but how coexpressed synaptotagmins interact remains unclear. We find that synaptotagmin-1 and synaptotagmin-7 when present alone act as standalone fast and slow Ca²⁺-sensors for vesicle fusion in mouse chromaffin cells. When present together, synaptotagmin-1 and synaptotagmin-7 are found in largely non-overlapping clusters on dense-core vesicles. Synaptotagmin-7 stimulates Ca²⁺-dependent vesicle priming and inhibits depriming, and it promotes ubMunc13-2- and phorbolester-dependent priming, especially at low resting calcium concentrations. The priming effect of synaptotagmin-7 increases the number of vesicles fusing via synaptotagmin-1, while negatively affecting their fusion speed, indicating both synergistic and competitive interactions between synaptotagmins. Synaptotagmin-7 places vesicles in close membrane apposition (<6 nm); without it, vesicles accumulate out of reach of the fusion complex (20-40 nm). We suggest that a synaptotagmin-7-dependent movement toward the membrane is involved in Munc13-2/phorbolester/Ca²⁺-dependent priming as a prelude to fast and slow exocytosis triggering.

Unraveling the Nanoscopic Organization and Function of Central Mammalian Presynapses With Super-Resolution Microscopy

The complex, nanoscopic scale of neuronal function, taking place at dendritic spines, axon terminals, and other minuscule structures, cannot be adequately resolved using standard, diffraction-limited imaging techniques. The last couple of decades saw a rapid evolution of imaging methods that overcome the diffraction limit imposed by Abbe's principle. These techniques, including structured illumination microscopy (SIM), stimulated emission depletion (STED), photo-activated localization microscopy (PALM), and stochastic optical reconstruction microscopy (STORM), among others, have revolutionized our understanding of synapse biology. By exploiting the stochastic nature of fluorophore light/dark states or non-linearities in the interaction of fluorophores with light, by using modified illumination strategies that limit the excitation area, these methods can achieve spatial resolutions down to just a few tens of nm or less. Here, we review how these advanced imaging techniques have contributed to unprecedented insight into the nanoscopic organization and function of mammalian neuronal presynapses, revealing new organizational principles or lending support to existing views, while raising many important new questions. We further discuss recent technical refinements and newly developed tools that will continue to expand our ability to delve deeper into how synaptic function is orchestrated at the nanoscopic level.

The role of histology on endometrial cancer survival disparities in diverse Florida

Background

Endometrial cancer (EC) mortality is particularly high among non-Hispanic Blacks and is twice that of non-Hispanic Whites. However, comparisons of EC survival outcomes by race/ethnicity are often confounded by histology and grade. Here, we analyze EC survival disparities in multiracial Florida with a focus on EC types (1 and 2) and subtypes, defined according to histology and grade.

Methods

All 27,809 cases of EC diagnosed during 2005–2016 were obtained from the Florida Cancer Registry. Age-standardized, 5-year cause-specific survival by race/ethnicity and histological type were calculated. Fine and Gray competing risk regression was used to estimate sub-distribution hazard ratios (sHRs) for associations between risk of death due to EC and potential predictive factors such as histology/grade, age, stage at diagnosis, and insurance.

Results

Type 2 EC accounted for only 38.7% of all incident EC-cases but 74.6% of all EC-deaths. Blacks were disproportionately affected by type 2 EC (57.6%) compared to Whites, Hispanics, and Asians (35.6%, 37.7%, and 43.0%, respectively). Age-adjusted 5-year survival for types 1 and 2 were 85.3% and 51.6%, respectively; however, there was wide variation within type 2 subtypes, ranging from 60.2% for mixed cell EC to as low as 30.1% for carcinosarcoma. In the multivariable model, Blacks with type 2 EC had a 23% higher risk of death due to EC (sHR: 1.23, 95%CI: 1.12–1.36) compared to Whites.

Conclusions

Population-based analyses should consider the histological heterogeneity of EC because the less common type 2 EC drives racial/ethnic survival disparities in EC. Black women have a higher proportion of more aggressive histological types and an overall higher risk of death due to EC than Whites. To the extent that some of these histological types may be considered different diseases and require specific treatment approaches, further research on etiology and prognosis for detailed type 2 EC subtypes is warranted.

Epidemiology and Etiology of Leukemia and Lymphoma

Available evidence suggests that the incidence of leukemia and lymphoma tends to be higher in highly developed regions of the world and among Whites in the United States. Temporal trends in incidence are dynamic and multifactorial; for instance, the incidence of non-Hodgkin's lymphoma increased around the turn of the century, in part because of the acquired immune deficiency syndrome (AIDS) epidemic. Most leukemias and lymphomas are sporadic and the specific etiology remains elusive. Still, research shows that these malignancies often develop in the context of genetic abnormalities, immunosuppression, and exposure to risk factors like ionizing radiation, carcinogenic chemicals, and oncogenic viruses. The prognosis varies by subtype, with poorer survival outcomes for acute leukemias among adults, and more favorable outcomes for Hodgkin's lymphoma. At a time when specific prevention efforts targeting these malignancies are nonexistent, there is a great need to ensure equitable access to diagnostic services and treatments worldwide.

Cancer mortality among US blacks: Variability between African Americans, Afro-Caribbeans, and Africans

INTRODUCTION

Aggregation of all Black populations in US cancer mortality profiles masks remarkable heterogeneity by place of birth. Comparing U.S-born African Americans with African and Afro-Caribbean immigrants may highlight specific cancer prevention and control needs and clarify global cancer epidemiology. Such a comparison has yet to be undertaken on a population basis.

METHODS

Using 2012-2017 vital statistics data from California, Florida, Minnesota and New York, age-standardized cancer mortality rates were computed for distinct Black populations. Comparisons were made to the majority White population using mortality rate ratios (MRR) obtained from negative binomial regression.

RESULTS

Of the 83,460 cancer deaths analyzed among Blacks, nearly 20 % were immigrants. African males and females had the lowest all-sites-combined cancer mortality rates (121 and 99 per 100,000, respectively), African Americans had the highest (232 and 163), while Afro-Caribbean were in between (140 and 106 respectively). The average Black:White MRR was significant for prostate (2.11), endometrial (2.05), stomach (2.02), multiple myeloma (1.87), premenopausal breast (1.66), liver (1.58) and cervical (1.56) cancers, (P < 0.05).

CONCLUSION

While, in aggregate, Blacks in the US have high cancer mortality rates, race itself is not the primary determinant of these disparities. Black immigrant populations show lower cancer mortality than both African Americans and Whites, especially for cancers where environmental factors feature more predominantly: lung, colorectal and breast. Even for cancers with high mortality among all African-descent groups, this study suggests a complex interplay between genetic and environmental factors. Endometrial cancer was unique; mortality rates were similarly high for all three analyzed Black groups.

The association between etiology of hepatocellular carcinoma and race-ethnicity in Florida

BACKGROUND AND AIM

The incidence of hepatocellular carcinoma (HCC) has risen considerably in the US since 1980. The main causes include metabolic disorders (NAFLD, diabetes, obesity, metabolic syndrome), alcohol-related disease (ALD) and hepatitis C and B virus infections (HCV, HBV). Etiology-specific HCC incidence rates by detailed race-ethnicity are needed to improve HCC control and prevention efforts.

METHODS

All HCC cases diagnosed in Florida during 2014-2015 were linked to statewide hospital discharge data to determine etiology. Age-specific and age-adjusted rates were used to assess the intersection between etiology and detailed racial-ethnicities, including White, African American, Afro-Caribbean, Asian, Cuban, Puerto Rican and Continental Hispanic (Mexican, South and Central American).

RESULTS

Of 3666 HCC cases, 2594 matched with discharge data. HCV was the leading cause of HCC among men and women (50% and 43% respectively), followed by metabolic disorders (25% and 37%) and ALD (16% and 9%). Puerto Rican and African American men had the highest HCV-HCC rates, 7.9 and 6.3 per 100 000 respectively. Age-specific rates for HCV-HCC peaked among baby boomers (those born in 1945-1965). Metabolic-HCC rates were highest among populations above age 70 and among Continental Hispanics. Afro-Caribbean men had high rates of HBV-HCC, whereas Puerto Rican men had high ALD-HCC.

CONCLUSIONS

HCC etiology is associated with specific race/ethnicity. While HCV-related HCC rates are projected to decrease soon, HCC will continue to affect Hispanics disproportionately, based on higher rates of metabolic-HCC (and ALD-HCC) among Continental Hispanics, who demographically represent 80% of all US Hispanics. Multifaceted approaches for HCC control and prevention are needed.

Endophilin-A coordinates priming and fusion of neurosecretory vesicles via intersectin

Endophilins-A are conserved endocytic adaptors with membrane curvature-sensing and -inducing properties. We show here that, independently of their role in endocytosis, endophilin-A1 and endophilin-A2 regulate exocytosis of neurosecretory vesicles. The number and distribution of neurosecretory vesicles were not changed in chromaffin cells lacking endophilin-A, yet fast capacitance and amperometry measurements revealed reduced exocytosis, smaller vesicle pools and altered fusion kinetics. The levels and distributions of the main exocytic and endocytic factors were unchanged, and slow compensatory endocytosis was not robustly affected. Endophilin-A’s role in exocytosis is mediated through its SH3-domain, specifically via a direct interaction with intersectin-1, a coordinator of exocytic and endocytic traffic. Endophilin-A not able to bind intersectin-1, and intersectin-1 not able to bind endophilin-A, resulted in similar exocytic defects in chromaffin cells. Altogether, we report that two endocytic proteins, endophilin-A and intersectin-1, are enriched on neurosecretory vesicles and regulate exocytosis by coordinating neurosecretory vesicle priming and fusion.

Endophilins-A are conserved membrane-associated proteins required for endocytosis. Here, the authors report that endophilins-A also promote exocytosis of neurosecretory vesicles by coordinating priming and fusion through intersectin-1, independently of their roles in different types of endocytosis.

Risk of Cancer Death Among White, Black, and Hispanic Populations in South Florida

Background

The cancer burden in South Florida, with a population of more than 6 million with a heavily Hispanic and large Afro-Caribbean population, has not been quantified.

Methods

We analyzed 2012–2016 cancer mortality data from South Florida for white, Hispanic, and black populations with disaggregation for Cuban, Puerto Rican, South American, African American, and Afro-Caribbean groups. We calculated cancer site-specific and all-sites combined age-adjusted mortality rates, and we used negative binomial regression to determine mortality rate ratios to compare South Florida’s cancer mortality rates with those of the rest of the nation.

Results

We analyzed 53,837 cancer deaths. Per 100,000 population, cancer mortality rates in South Florida were similar among white (173 per 100,000) and black (176 per 100,000) men and among white and black women (133 for both), and they were lowest among Hispanic men (151 per 100,000) and women (93 per 100,000). However, compared with their counterparts nationally, Hispanic residents in South Florida had higher cancer mortality rates, largely driven by Cuban residents, and mortality rates among white and black residents, especially male residents, were substantially lower. Liver cancer rates were high among white and Puerto Rican “baby boomers”; lung cancer mortality was low among all groups except Cuban men; cervical cancer was high among white, black, and Puerto Rican women.

Conclusion

Cancer patterns are not monochromatic in all US regions; South Florida is distinctive. Meeting the needs of an aging diverse population presents challenges for all major metropolitan areas. Expanding surveillance, increasing minority participation in clinical trials, and investing in culturally specific community-based health promotion must continue.

Liver cancer: A leading cause of cancer death in the United States and the role of the 1945-1965 birth cohort by ethnicity

Liver cancer is highly fatal and the most rapidly increasing cancer in the US, where chronic hepatitis C (HCV) infection is the leading etiology. HCV is particularly prevalent among the 1945-1965 birth cohort, the so-called “baby boomers”. Focusing on this cohort-etiology link, we aim to characterize liver cancer patterns for 15 unique US populations: White, African American, Mexican Immigrant, Mexican American, Cuban and Chinese, among others.

Methods

Individual-level mortality data from 2012–2016 from the health departments of 3 large states – California, Florida, New York – were pooled to compute liver cancer mortality rates for each racial/ethnic group and for 2 birth cohorts of interest: “1945–1965 cohort” and “older cohort”.

Results

Liver cancer is a major cause of cancer death among all US male groups and the leading cause in Mexican American men. Over 50% of the age-adjusted liver cancer mortality of White, African American, Mexican American, and Puerto Rican males came from the 1945-1965 birth cohort. In contrast, foreign-born male and all female populations had higher liver cancer mortality originating from the older cohort. Internationally, US White male baby boomers had a 49% higher liver cancer mortality rate than their counterparts in Europe (mortality rate ratio 1.49; 95% CI 1.43–1.56).

Conclusions

Populations burdened disproportionately by liver cancer in the 1945–1965 cohort include US-born males who were all present in the US during the 1960s–1990s when significant HCV transmission took place; these individuals will benefit most from HCV screening and treatment. For the others, including all women, Asian subgroups, and especially burgeoning Hispanic immigrant populations, comprehensive liver cancer prevention efforts will require detailed study of the distribution of etiologies.

Lay summary

Liver cancer, a major cause of cancer death among US males, is increasing. The causes of liver cancer are varied, including hepatitis C, hepatitis B, alcohol-related liver disease, and non-alcoholic fatty liver disease. Racial/ethnic groups are impacted differently, but the highest rates are seen among US-born men born between 1945–1965, the so-called “baby boomers”, whether White, Black, or Hispanic, likely linked to the known high prevalence of hepatitis C infection among this cohort.

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Liver cancer is now the leading cause of cancer death among Mexican American males.

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Rates vary intra-racially: e.g. Vietnamese have high rates; South Asians have low.

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US-born male “baby boomers” of any race/ethnicity have the highest liver cancer mortality.

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Foreign-born men and all women have higher mortality at older ages, 70 or more.

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In the “baby boomer” cohort, US Whites have higher liver cancer mortality than Europeans.