Disaggregating Hispanic American Cancer Mortality Burden by Detailed Ethnicity

BACKGROUND

Hispanics are the largest minority population in the United States (18%). They represent a heterogeneous and growing population. Cancer is the leading cause of death among Hispanics, yet few studies have described cancer mortality burden by specific Hispanic group nationwide.

METHODS

Cancer-related deaths from U.S. death certificates for the years 2003-2012 were analyzed for decedents identifying as Mexican, Puerto Rican, Cuban, and Central or South American. We calculated descriptive statistics, including potential years of lives lost (PYLL), age-adjusted rates, standardized mortality ratios, and fitted JoinPoint regression models, to evaluate annual trends by Hispanic group, using non-Hispanic Whites (NHW) as the reference population.

RESULTS

We identified 287,218 cancer-related deaths among Hispanics and 4,570,559 among NHWs. Mortality trends were heterogeneous across Hispanic groups. Female NHWs and male Puerto Ricans had the greatest rates of adjusted PYLL per 1,000 (NHWs, 19.6; Puerto Ricans, 16.5). Liver cancer was ranked among the top 5 cancer-related deaths for every Hispanic group, but not for NHWs. Stomach cancer mortality was twice as high for most Hispanic groups when compared with NHWs and especially high for Mexicans [male standardized mortality ratio (SMR), 2.07; 95% confidence interval (CI), 2.01-2.13; female SMR, 2.62; 95% CI, 2.53-2.71].

CONCLUSIONS

We observed marked heterogeneity in cancer mortality across Hispanic groups. Several cancers affect Hispanics disproportionately compared with NHWs. Screening programs in Hispanics should be considered for stomach and liver cancer.

IMPACT

Disaggregated analysis of Hispanics is needed to fully understand cancer burden among the diverse Hispanic population and is critical for cancer prevention and control efforts.

Mortality of women with ductal carcinoma in situ of the breast: a population-based study from the Girona province, Spain (1994-2013)

PURPOSE

We aim to comprehensively describe the incidence and mortality trends of ductal carcinoma in situ (DCIS) in the Girona province, Spain (1994-2013) and to estimate the all-cause mortality excess risk of diagnosed women.

METHODS

Age-standardized rates of DCIS were estimated between 1994 and 2013. Standard mortality ratios (SMR) and absolute excess mortality were calculated overall and by tumor and patient characteristics. A sensitivity analysis was conducted excluding cases with a subsequent invasive breast cancer (sIBC).

RESULTS

Of the 641 women included, 56 died (follow-up time: 8.4 person-years). Between 1994 and 2013, a significant increase in incidence and decrease in mortality was identified among women aged between 50 and 69 years old. Neoplasms and circulatory system disease were the most common causes of death. No excess risk of death was found overall, except for women aged < 50 years (SMR = 3.44, 95% CI 1.85; 6.40) and those with a sIBC (SMR = 2.51, 95% CI 1.26; 5.02), risk that lessened when cases with sIBC were excluded. Patients with sIBC also showed an excess risk (SMR = 2.29, 95% CI 1.03; 5.10).

CONCLUSIONS

Among women aged 50-69 years old, incidence of DCIS has significantly increased yet mortality has decreased. Overall, the all-cause mortality risk of women diagnosed with DCIS remains similar to that of the general population except for women diagnosed before age 50 and those with sIBC, who showed a significant increased risk. Differential management of these patients should be considered.

Cancer Statistics for Hispanics/Latinos, 2018

Cancer is the leading cause of death among Hispanics/Latinos, who represent the largest racial/ethnic minority group in the United States, accounting for 17.8% (57.5 million) of the total population in the continental United States and Hawaii in 2016. In addition, more than 3 million Hispanic Americans live in the US territory of Puerto Rico. Every 3 years, the American Cancer Society reports on cancer occurrence, risk factors, and screening for Hispanics in the United States based on data from the National Cancer Institute, the North American Association of Central Cancer Registries, and the Centers for Disease Control and Prevention. For the first time, contemporary incidence and mortality rates for Puerto Rico, which has a 99% Hispanic population, are also presented. An estimated 149,100 new cancer cases and 42,700 cancer deaths will occur among Hispanics in the continental United States and Hawaii in 2018. For all cancers combined, Hispanics have 25% lower incidence and 30% lower mortality compared with non-Hispanic whites, although rates of infection-related cancers, such as liver, are up to twice as high in Hispanics. However, these aggregated data mask substantial heterogeneity within the Hispanic population because of variable cancer risk, as exemplified by the substantial differences in the cancer burden between island Puerto Ricans and other US Hispanics. For example, during 2011 to 2015, prostate cancer incidence rates in Puerto Rico (146.6 per 100,000) were 60% higher than those in other US Hispanics combined (91.6 per 100,000) and 44% higher than those in non-Hispanic whites (101.7 per 100,000). Prostate cancer is also the leading cause of cancer death among men in Puerto Rico, accounting for nearly 1 in 6 cancer deaths during 2011-2015, whereas lung cancer is the leading cause of cancer death among other US Hispanic men combined. Variations in cancer risk are driven by differences in exposure to cancer-causing infectious agents and behavioral risk factors as well as the prevalence of screening. Strategies for reducing cancer risk in Hispanic populations include targeted, culturally appropriate interventions for increasing the uptake of preventive services and reducing cancer risk factor prevalence, as well as additional funding for Puerto Rico-specific and subgroup-specific cancer research and surveillance.

Cancer Site-Specific Disparities in New York, Including the 1945-1965 Birth Cohort's Impact on Liver Cancer Patterns

Background: Analyses of cancer patterns by detailed racial/ethnic groups in the Northeastern United States are outdated.Methods: Using 2008-2014 death data from the populous and diverse New York State, mortality rates and regression-derived ratios with corresponding 95% confidence intervals (CIs) were computed to compare Hispanic, non-Hispanic white (NHW), non-Hispanic black (NHB), Asian populations, and specific Hispanic and NHB subgroups: Puerto Rican, Dominican, South American, Central American, U.S.-born black, and Caribbean-born black. Special analyses on liver cancer mortality, given the higher prevalence of hepatitis C infection among the 1945-1965 birth cohort, were performed.Results: A total of 244,238 cancer-related deaths were analyzed. Mortality rates were highest for U.S.-born blacks and lowest for South Americans and Asians. Minority groups had higher mortality from liver and stomach cancer than NHWs; Hispanics and NHBs also had higher mortality from cervical and prostate cancers. Excess liver cancer mortality among Puerto Rican and U.S.-born black men was observed, particularly for the 1945-1965 birth cohort, with mortality rate ratios of 4.27 (95% CI, 3.82-4.78) and 3.81 (95% CI, 3.45-4.20), respectively.Conclusions: U.S.-born blacks and Puerto Ricans, who share a common disadvantaged socioeconomic profile, bear a disproportionate burden for many cancers, including liver cancer among baby boomers. The relatively favorable cancer profile for Caribbean-born blacks contrasts with their U.S.-born black counterparts, implying that race per se is not an inevitable determinant of higher mortality among NHBs.Impact: Disaggregation by detailed Hispanic and black subgroups in U.S. cancer studies enlightens our understanding of the epidemiology of cancer and is fundamental for cancer prevention and control efforts. Cancer Epidemiol Biomarkers Prev; 27(8); 917-27. ©2018 AACR.

Doc2B acts as a calcium sensor for vesicle priming requiring synaptotagmin-1, Munc13-2 and SNAREs

Doc2B is a cytosolic protein with binding sites for Munc13 and Tctex-1 (dynein light chain), and two C2-domains that bind to phospholipids, Ca²⁺ and SNAREs. Whether Doc2B functions as a calcium sensor akin to synaptotagmins, or in other calcium-independent or calcium-dependent capacities is debated. We here show by mutation and overexpression that Doc2B plays distinct roles in two sequential priming steps in mouse adrenal chromaffin cells. Mutating Ca²⁺-coordinating aspartates in the C2A-domain localizes Doc2B permanently at the plasma membrane, and renders an upstream priming step Ca²⁺-independent, whereas a separate function in downstream priming depends on SNARE-binding, Ca²⁺-binding to the C2B-domain of Doc2B, interaction with ubMunc13-2 and the presence of synaptotagmin-1. Another function of Doc2B – inhibition of release during sustained calcium elevations – depends on an overlapping protein domain (the MID-domain), but is separate from its Ca²⁺-dependent priming function. We conclude that Doc2B acts as a vesicle priming protein.

Stomach cancer survival in the United States by race and stage (2001-2009): Findings from the CONCORD-2 study

BACKGROUND

Stomach cancer was a leading cause of cancer-related deaths early in the 20th century and has steadily declined over the last century in the United States. Although incidence and death rates are now low, stomach cancer remains an important cause of morbidity and mortality in black, Asian and Pacific Islander, and American Indian/Alaska Native populations.

METHODS

Data from the CONCORD-2 study were used to analyze stomach cancer survival among males and females aged 15 to 99 years who were diagnosed in 37 states covering 80% of the US population. Survival analyses were corrected for background mortality using state-specific and race-specific (white and black) life tables and age-standardized using the International Cancer Survival Standard weights. Net survival is presented up to 5 years after diagnosis by race (all, black, and white) for 2001 through 2003 and 2004 through 2009 to account for changes in collecting Surveillance, Epidemiology, and End Results Summary Stage 2000 data from 2004.

RESULTS

Almost one-third of stomach cancers were diagnosed at a distant stage among both whites and blacks. Age-standardized 5-year net survival increased between 2001 to 2003 and 2004 to 2009 (26.1% and 29%, respectively), and no differences were observed by race. The 1-year, 3-year, and 5-year survival estimates were 53.1%, 33.8%, and 29%, respectively. Survival improved in most states. Survival by stage was 64% (local), 28.2% (regional), and 5.3% (distant).

CONCLUSIONS

The current results indicate high fatality for stomach cancer, especially soon after diagnosis. Although improvements in stomach cancer survival were observed, survival remained relatively low for both blacks and whites. Primary prevention through the control of well-established risk factors would be expected to have the greatest impact on further reducing deaths from stomach cancer. Cancer 2017;123:4994-5013. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Liver cancer survival in the United States by race and stage (2001-2009): Findings from the CONCORD-2 study

BACKGROUND

Worldwide, liver cancer is a leading cause of death for both men and women. The number of Americans who are diagnosed with and die of liver cancer has been rising slowly each year. Using data from the CONCORD-2 study, this study examined population-based survival by state, race, and stage at diagnosis.

METHODS

Data from 37 statewide registries, which covered 81% of the US population, for patients diagnosed during 2001-2009 were analyzed. Survival up to 5 years was adjusted for background mortality (net survival) with state- and race-specific life tables, and it was age-standardized with the International Cancer Survival Standard weights.

RESULTS

Liver cancer was diagnosed overall more often at the localized stage, with blacks being more often diagnosed at distant and regional stages than whites. 5-year net survival was 12.2% in 2001-2003 and 14.8% in 2004-2009. Whites had higher survival than blacks in both calendar periods (11.7% vs 9.1% and 14.3% vs 11.4%, respectively). During 2004-2009, 5-year survival was 25.7% for localized-stage disease, 9.5% for regional-stage disease, and 3.5% for distant-stage disease.

CONCLUSIONS

Some progress has occurred in survival for patients with liver cancer, but 5-year survival remains low, even for those diagnosed at the localized stage. Efforts directed at controlling well-established risk factors such as hepatitis B may have the greatest impact on reducing the burden of liver cancer in the United States. Cancer 2017;123:5059-78. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Phosphatidylinositol 4,5-bisphosphate optical uncaging potentiates exocytosis

Phosphatidylinositol-4,5-bisphosphate [PI(4,5)P₂] is essential for exocytosis. Classical ways of manipulating PI(4,5)P₂ levels are slower than its metabolism, making it difficult to distinguish effects of PI(4,5)P₂ from those of its metabolites. We developed a membrane-permeant, photoactivatable PI(4,5)P₂, which is loaded into cells in an inactive form and activated by light, allowing sub-second increases in PI(4,5)P₂ levels. By combining this compound with electrophysiological measurements in mouse adrenal chromaffin cells, we show that PI(4,5)P₂ uncaging potentiates exocytosis and identify synaptotagmin-1 (the Ca²⁺ sensor for exocytosis) and Munc13-2 (a vesicle priming protein) as the relevant effector proteins. PI(4,5)P₂ activation of exocytosis did not depend on the PI(4,5)P₂-binding CAPS-proteins, suggesting that PI(4,5)P₂ uncaging may bypass CAPS-function. Finally, PI(4,5)P₂ uncaging triggered the rapid fusion of a subset of readily-releasable vesicles, revealing a rapid role of PI(4,5)P₂ in fusion triggering. Thus, optical uncaging of signaling lipids can uncover their rapid effects on cellular processes and identify lipid effectors.

Cells in our body communicate by releasing compounds called transmitters that carry signals from one cell to the next. Packages called vesicles store transmitters within the signaling cell. When the cell needs to send a signal, the vesicles fuse with the cell's membrane and release their cargo. For many signaling processes, such as those used by neurons, this fusion is regulated, fast, and coupled to the signal that the cell receives to activate release. Specialized molecular machines made up of proteins and fatty acid molecules called signaling lipids enable this to happen.

One signaling lipid called PI(4,5)P₂ (short for phosphatidylinositol 4,5-bisphosphate) is essential for vesicle fusion as well as for other processes in cells. It interacts with several proteins that help it control fusion and the release of transmitter. While it is possible to study the role of these proteins using genetic tools to inactivate them, the signaling lipids are more difficult to manipulate. Existing methods result in slow changes in PI(4,5)P₂ levels, making it hard to directly attribute later changes to PI(4,5)P₂.

Walter, Müller, Tawfik et al. developed a new method to measure how PI(4,5)P₂ affects transmitter release in living mammalian cells, which causes a rapid increase in PI(4,5)P₂ levels. The method uses a chemical compound called “caged PI(4,5)P₂” that can be loaded into cells but remains undetected until ultraviolet light is shone on it. The ultraviolet light uncages the compound, generating active PI(4,5)P₂ in less than one second. Walter et al. found that when they uncaged PI(4,5)P₂ in this way, the amount of transmitter released by cells increased. Combining this with genetic tools, it was possible to investigate which proteins of the release machinery were required for this effect.

The results suggest that two different types of proteins that interact with PI(4,5)P₂ are needed: one must bind PI(4,5)P₂ to carry out its role and the other helps PI(4,5)P₂ accumulate at the site of vesicle fusion. The new method also allowed Walter et al. to show that a fast increase in PI(4,5)P₂ triggers a subset of vesicles to fuse very rapidly. This shows that PI(4,5)P₂ rapidly regulates the release of transmitter. Caged PI(4,5)P₂ will be useful to study other processes in cells that need PI(4,5)P₂, helping scientists understand more about how signaling lipids control many different events at cellular membranes.

Migration from Mexico to the United States: A high-speed cancer transition

Differences and similarities in cancer patterns between the country of Mexico and the United States' Mexican population, 11% of the entire US population, have not been studied. Mortality data from 2008 to 2012 in Mexico and California were analyzed and compared for causes of cancer death among adult and pediatric populations, using standard techniques and negative binomial regression. A total of 380,227 cancer deaths from Mexico and California were included. Mexican Americans had 49% and 13% higher mortality than their counterparts in Mexico among males and females, respectively. For Mexican Immigrants in the US, overall cancer mortality was similar to Mexico, their country of birth, but all-cancers-combined rates mask wide variation by specific cancer site. The most extreme results were recorded when comparing Mexican Americans to Mexicans in Mexico: with mortality rate ratios ranging from 2.72 (95% CI: 2.44-3.03) for colorectal cancer in males to 0.28 (95% CI: 0.24-0.33) for cervical cancer in females. These findings further reinforce the preeminent role that the environment, in its multiple aspects, has on cancer. Overall, mortality from obesity and tobacco-related cancers was higher among Mexican origin populations in the US compared to Mexico, suggesting a higher risk for these cancers, while mortality from prostate, stomach, and especially cervical and pediatric cancers was markedly higher in Mexico. Among children, brain cancer and neuroblastoma patterns suggest an environmental role in the etiology of these malignancies as well. Partnered research between the US and Mexico for cancer studies is warranted.

Formin 2 links neuropsychiatric phenotypes at young age to an increased risk for dementia

Age-associated memory decline is due to variable combinations of genetic and environmental risk factors. How these risk factors interact to drive disease onset is currently unknown. Here we begin to elucidate the mechanisms by which post-traumatic stress disorder (PTSD) at a young age contributes to an increased risk to develop dementia at old age. We show that the actin nucleator Formin 2 (Fmn2) is deregulated in PTSD and in Alzheimer's disease (AD) patients. Young mice lacking the Fmn2 gene exhibit PTSD-like phenotypes and corresponding impairments of synaptic plasticity, while the consolidation of new memories is unaffected. However, Fmn2 mutant mice develop accelerated age-associated memory decline that is further increased in the presence of additional risk factors and is mechanistically linked to a loss of transcriptional homeostasis. In conclusion, our data present a new approach to explore the connection between AD risk factors across life span and provide mechanistic insight to the processes by which neuropsychiatric diseases at a young age affect the risk for developing dementia.

High cancer mortality for US-born Latinos: evidence from California and Texas

Background

Latinos born in the US, 36 million, comprise 65% of all US Latinos. Yet their cancer experience is nearly always analyzed together with their foreign-born counterparts, 19 million, who constitute a steady influx of truly lower-risk populations from abroad. To highlight specific cancer vulnerabilities for US-born Latinos, we compare their cancer mortality to the majority non-Latino white (NLW) population, foreign-born Latinos, and non-Latino blacks.

Methods

We analyzed 465,751 cancer deaths from 2008 to 2012 occurring among residents of California and Texas, the two most populous states, accounting for 47% of US Latinos. This cross-sectional analysis, based on granular data obtained from death certificates on cause of death, age, race, ethnicity and birthplace, makes use of normal standardization techniques and negative binomial regression models.

Results

While Latinos overall have lower all-cancers-combined mortality rates than NLWs, these numbers were largely driven by low rates among the foreign born while mortality rates for US-born Latinos approach those of NLWs. Among Texas males, rates were 210 per 100,000 for NLWs and 166 for Latinos combined, but 201 per 100,000 for US-born Latinos and 125 for foreign-born Latinos. Compared to NLWs, US-born Latino males in California had mortality rate ratios of 2.83 (95% CI: 2.52–3.18) for liver cancer, 1.44 (95% CI: 1.30–1.61) for kidney cancer, and 1.25 (95% CI: 1.17–1.34) for colorectal cancer (CRC). Texas results showed a similar site-specific pattern.

Conclusions

Specific cancer patterns for US-born Latinos, who have relatively high cancer mortality, similar overall to NLWs, are masked by aggregation of all Latinos, US-born and foreign-born. While NLWs had high mortality for lung cancer, US-born Latinos had high mortality for liver, kidney and male colorectal cancers. HCV testing and reinforcement of the need for CRC screening should be a priority in this specific and understudied population. The unprecedented proximity of overall rates between NLWs and US-born Latino populations runs counter to the prevailing narrative of Latinos having significantly lower cancer risk and mortality. Birthplace data are critical in detecting meaningful differences among Latinos; these findings merit not only clinical but also public health attention.

Black Heterogeneity in Cancer Mortality: US-Blacks, Haitians, and Jamaicans

INTRODUCTION

The quantitative intraracial burden of cancer incidence, survival and mortality within black populations in the United States is virtually unknown.

METHODS

We computed cancer mortality rates of US- and Caribbean-born residents of Florida, specifically focusing on black populations (United States, Haiti, Jamaica) and compared them using age-adjusted mortality ratios obtained from Poisson regression models. We compared the mortality of Haitians and Jamaicans residing in Florida to populations in their countries of origin using Globocan.

RESULTS

We analyzed 185,113 cancer deaths from 2008 to 2012, of which 20,312 occurred in black populations. The overall risk of death from cancer was 2.1 (95% CI: 1.97-2.17) and 1.6 (95% CI: 1.55-1.71) times higher for US-born blacks than black Caribbean men and women, respectively (P < .001).

CONCLUSIONS

Race alone is not a determinant of cancer mortality. Among all analyzed races and ethnicities, including Whites and Hispanics, US-born blacks had the highest mortality rates while black Caribbeans had the lowest. The biggest intraracial difference was observed for lung cancer, for which US-blacks had nearly 4 times greater mortality risk than black Caribbeans. Migration from the islands of Haiti and Jamaica to Florida resulted in lower cancer mortality for most cancers including cervical, stomach, and prostate, but increased or stable mortality for 2 obesity-related cancers, colorectal and endometrial cancers. Mortality results in Florida suggest that US-born blacks have the highest incidence rate of "aggressive" prostate cancer in the world, rather than Caribbean men.

Cancer Mortality in Hispanic Ethnic Groups

Background: Cancer is the leading cause of death among Hispanics. The burden of cancer mortality within Hispanic groups has not been well quantified.Methods: Cancer mortality rates for 2008-2012 in Florida were computed on the basis of race, ethnicity, and birthplace, specifically focusing on major Hispanic groups-Mexicans, Puerto Ricans, Cubans, Central Americans, South Americans, and Dominicans. Age-adjusted mortality rate ratios derived from negative binomial regression were used to compare Hispanics, aggregated and by group, to nonHispanic whites (NHW).Results: A total of 205,369 cancer deaths from 2008-2012 were analyzed, of which 22,042 occurred in Hispanics. Overall cancer mortality rates were lower for Hispanics, 159 and 100 per 100,000 in males and females, respectively, compared with 204 and 145 per 100,000 in NHWs, largely driven by relatively low rates of lung and breast cancers among Hispanics. However, Hispanics had a higher risk of death from stomach and liver cancers, both infection-related. Of all Hispanic groups, Mexicans had the lowest mortality, whereas Cubans had the highest, with significantly higher mortality for colorectal, endometrial, and prostate cancers.Conclusions: Compared with other Hispanic groups, Cubans and Puerto Ricans had significantly higher rates. For these longer-established populations in the United States, increases in diet and obesity-related cancers are evident. Some groups show excesses that clearly fall out of the common Hispanic patterns, with implications for public health: Cubans for colorectal cancer, Puerto Ricans for liver cancer, and Dominicans for prostate cancer.Impact: Cancer mortality outcomes in Hispanics vary between ethnic groups. Research and public health strategies should consider this heterogeneity. Cancer Epidemiol Biomarkers Prev; 26(3); 376-82. ©2017 AACR.

Colorectal Cancer Trends in California and the Need for Greater Screening of Hispanic Men

INTRODUCTION

Colorectal cancer (CRC) incidence and mortality rates have decreased dramatically since 1990, both nationally and in California, except among Hispanic men. This study examined trends in CRC incidence, mortality, and survival to determine likely contributing factors for the differential trends between Hispanic and non-Hispanic white men in California.

METHODS

California Cancer Registry data were used to identify 23,157 Hispanic and 114,944 white men diagnosed with CRC between 1990 and 2012. Joinpoint trends in incidence, mortality, and 5-year relative survival were examined by age, stage at diagnosis, and tumor location. Data used in the study were extracted from the California Cancer Registry database and analyzed in 2015.

RESULTS

Both incidence and mortality rates decreased substantially among white men between 1990 and 2012, but no corresponding decrease was observed among Hispanic men. Both groups experienced similar trends in survival and stage at diagnosis over time. White men had greater declines in CRC incidence and mortality in all age groups, particularly those aged >50 years. Hispanic men had a significantly higher proportion (65%) of tumors in the distal colon than white men (59%).

CONCLUSIONS

CRC incidence and mortality rates have decreased among white men since 1990, but not among Hispanic men. Results from this study suggest lower screening rates may be an important reason why CRC rates in California did not decline in Hispanic men. Effective strategies aimed at both Hispanics and their healthcare providers are needed to increase CRC screening among Hispanic men and reduce their CRC burden.

Regulation of Ca2+ channels by SNAP-25 via recruitment of syntaxin-1 from plasma membrane clusters

SNAP-25 regulates Ca²⁺ channels in an unknown manner. Endogenous and exogenous SNAP-25 inhibit Ca²⁺ currents indirectly by recruiting syntaxin-1 from clusters on the plasma membrane, thereby making it available for Ca²⁺ current inhibition. Thus the cell can regulate Ca²⁺ influx by expanding or contracting syntaxin-1 clusters.

SNAP-25 regulates Ca²⁺ channels, with potentially important consequences for diseases involving an aberrant SNAP-25 expression level. How this regulation is executed mechanistically remains unknown. We investigated this question in mouse adrenal chromaffin cells and found that SNAP-25 inhibits Ca²⁺ currents, with the B-isoform being more potent than the A-isoform, but not when syntaxin-1 is cleaved by botulinum neurotoxin C. In contrast, syntaxin-1 inhibits Ca²⁺ currents independently of SNAP-25. Further experiments using immunostaining showed that endogenous or exogenous SNAP-25 expression recruits syntaxin-1 from clusters on the plasma membrane, thereby increasing the immunoavailability of syntaxin-1 and leading indirectly to Ca²⁺ current inhibition. Expression of Munc18-1, which recruits syntaxin-1 within the exocytotic pathway, does not modulate Ca²⁺ channels, whereas overexpression of the syntaxin-binding protein Doc2B or ubMunc13-2 increases syntaxin-1 immunoavailability and concomitantly down-regulates Ca²⁺ currents. Similar findings were obtained upon chemical cholesterol depletion, leading directly to syntaxin-1 cluster dispersal and Ca²⁺ current inhibition. We conclude that clustering of syntaxin-1 allows the cell to maintain a high syntaxin-1 expression level without compromising Ca²⁺ influx, and recruitment of syntaxin-1 from clusters by SNAP-25 expression makes it available for regulating Ca²⁺ channels. This mechanism potentially allows the cell to regulate Ca²⁺ influx by expanding or contracting syntaxin-1 clusters.

Cancer incidence among Asian American populations in the United States, 2009-2011

Cancer incidence disparities exist among specific Asian American populations. However, the existing reports exclude data from large metropoles like Chicago, Houston and New York. Moreover, incidence rates by subgroup have been underestimated due to the exclusion of Asians with unknown subgroup. Cancer incidence data for 2009 to 2011 for eight states accounting for 68% of the Asian American population were analyzed. Race for cases with unknown subgroup was imputed using stratified proportion models by sex, age, cancer site and geographic regions. Age-standardized incidence rates were calculated for 17 cancer sites for the six largest Asian subgroups. Our analysis comprised 90,709 Asian and 1,327,727 non-Hispanic white cancer cases. Asian Americans had significantly lower overall cancer incidence rates than non-Hispanic whites (336.5 per 100,000 and 541.9 for men, 299.6 and 449.3 for women, respectively). Among specific Asian subgroups, Filipino men (377.4) and Japanese women (342.7) had the highest overall incidence rates while South Asian men (297.7) and Korean women (275.9) had the lowest. In comparison to non-Hispanic whites and other Asian subgroups, significantly higher risks were observed for colorectal cancer among Japanese, stomach cancer among Koreans, nasopharyngeal cancer among Chinese, thyroid cancer among Filipinos, and liver cancer among Vietnamese. South Asians had remarkably low lung cancer risk. Overall, Asian Americans have a lower cancer risk than non-Hispanic whites, except for nasopharyngeal, liver and stomach cancers. The unique portrayal of cancer incidence patterns among specific Asian subgroups in this study provides a new baseline for future cancer surveillance research and health policy.

Abstract C35: Filipinos and blacks at a disadvantage for breast cancer survival and in-state disparities in Nevada

Health disparities may differ by geographical area depending on contextual factors. With below average incidence, low mammography prevalence and above average mortality rates, the study of breast cancer survival outcomes is of particular interest in the state of Nevada. The health infrastructure in Southern Nevada is currently not supported by an established MD-type School of Medicine, despite the size of the Las Vegas metropolis, 2 million. We studied survival disparities for females with breast cancer in the Silver State for the period 2003-2010.

Data came from the Nevada Central Cancer Registry and cases were followed-up until Dec 31 2012 using hospital records as well as in-state and national death index linkages. We analyzed cause-specific survival rates using the actuarial method. We assessed the impact of (1) tumor-related factors: AJCC stage at diagnosis, grade of differentiation, estrogen receptors; (2) demographic factors including age, race-ethnicity (non-Hispanic Whites, non-Hispanic Blacks, Hispanics, Asian Filipino, Asian other, American Indian) , marital status; and (3) social factors such as insurance and socio-economic status on survival outcomes for breast cancer using Cox regression. For censoring times, we used the presumed-alive assumption.

A total of 11,110 cases of breast cancer cases diagnosed between 2003 and 2010 were analyzed. Survival in Northern Nevada –Reno was 88.2% after 5 years (95%CI 86.9-89.5) well within the US-SEER average of 87.0% (95%CI 86.9-87.2). Southern Nevada - Las Vegas lagged significantly behind with 83.1% (95%CI 82.2-84.0). Non-Hispanic Blacks had a 76.0% 5 year-survival (95%CI 72.6-79.4) and Filipino women 76.6% (71.3-82.0). In the multivariate analysis, Stage I, estrogen-receptor positive, and high grade of differentiation showed a lower mortality risk, while low SES and lack of insurance showed a higher mortality risk. After adjustment for all confounders, Black women showed higher mortality risk than Whites (HR 1.26 95%CI 1.06-1.50) and Southern Nevada had a 14% higher mortality risk compared to Northern Nevada for patients of the same age, race, insurance, stage at diagnosis (HR 1.14, 95%CI 1.00-1.30). The initial disadvantage for Filipino women in relation to Whites was no longer shown after adjustment for AJCC stage at diagnosis (HR 1.17, p&lt; 0.05).

Disparities according to tumor-related factors in Nevada were not different from those in the rest of the nation. However, unique disparities were observed according to demographic factors. A significant survival difference between the Northern and Southern regions of Nevada, with similar prevalence of mammography, and after adjustment for all known confounders, suggests disparities in quality of healthcare associated or not with different treatment compliance patterns. Black women are disadvantaged despite adjustment for SES, stage and insurance type, while the Filipino disadvantage is modifiable since it is caused by an unfavorable distribution of stage at diagnosis.

Citation Format: Paulo S. Pinheiro, Nevena Cvijetic, Rachel Kelly, Carmen Ponce, Erin Kobetz-Kerman. Filipinos and blacks at a disadvantage for breast cancer survival and in-state disparities in Nevada. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr C35.

Abstract C36: Cancer incidence disparities among the Asian American population

Introduction: Asian Americans are the fastest growing race group in the United States, accounting for 5.7% of the total population in 2010. Previous research using cancer registry data studied cancer incidence rates by specific Asian group. However, those rates were underestimated, and possibly biased in relative terms, because Asian cancer cases without a recorded specific Asian group (also called not otherwise specified, NOS) were not taken into account. The purpose of this study was to produce comparable incidence rates for the six major Asian groups (Chinese, Filipino, Japanese, Korean, South Asian, and Vietnamese) by statistically adjusting for Asian NOS cases.

Methods: Cancer incidence data between 2009 and 2011 were obtained from the eight states with the highest numbers of Asian Americans covering 68.3% of the total Asian American population, the largest coverage for a study on specific Asian groups to date. Population denominators were derived from 2010 US Census. Asian NOS cases were distributed using stratified imputation by age, cancer site, gender, and geographic region. Age-standardized incidence rates for 19 cancer sites were computed for specific Asian groups and non-Hispanic whites to detect potential disparities among the Asian American population. In addition, incidence rates were compared with those in their countries of origin to investigate the changes in cancer risk associated with immigration to the United States.

Results: A total of 93,626 Asian and 1,325,051 non-Hispanic white cancer cases were analyzed. Asian Americans had significantly lower overall incidence rates than non-Hispanic whites (333.1 per 100,000 and 540.7 for men, and 299.4 and 448.5 for women, respectively). Filipino men (377.3) and Japanese women (343.0) had the highest overall incidence rates while South Asian men (296.8) and Korean women (276.2) had the lowest among specific Asian groups. Compared to their countries of origin, the overall incidence rates were higher in Asian Americans except among Koreans.

Conclusions: Asian Americans are disproportionately burdened by infection-related cancers, such as liver and stomach cancers, but not by cervical cancer. Considerable incidence disparities exist among specific Asian groups. Compared to non-Hispanic whites and other Asian groups, significantly higher colorectal cancer rates were observed in Japanese, stomach cancer in Koreans, nasopharyngeal cancer in Chinese, thyroid cancer in Filipinos, and liver cancer in Vietnamese. The disparities here found demonstrate the need for future research to explore the factors behind the increased susceptibility for some cancers and the apparent “protection” against others evident among specific Asian groups. In addition, public health efforts are needed to eliminate cancer disparities among specific Asian groups through improved prevention, screening and surveillance.

Citation Format: Hongbin Jin, Paulo S. Pinheiro. Cancer incidence disparities among the Asian American population. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr C36.

Spatial distribution and temporal evolution of DRONPA-fused SNAP25 clusters in adrenal chromaffin cells

Sub-diffraction imaging of plasma membrane localized proteins, such as the SNARE (Soluble NSF Attachment Protein Receptor) proteins involved in exocytosis, in fixed cells have resulted in images with high spatial resolution, at the expense of dynamical information. Here, we have imaged localized fluorescence bursts of DRONPA-fused SNAP-25 molecules in live chromaffin cells by Total Internal Reflection Fluorescence (TIRF) imaging. We find that this method allows tracking protein cluster dynamics over relatively long times (∼20 min.), partly due to the diffusion into the TIRF field of fresh molecules, making possible the simultaneous identification of cluster size, location and temporal evolution. The results indicate that the DRONPA-fused SNAP-25 clusters display rich dynamics, going from staying constant to disappearing and reappearing in specific cluster domains within minutes.

Identification of a Munc13-sensitive step in chromaffin cell large dense-core vesicle exocytosis

It is currently unknown whether the molecular steps of large dense-core vesicle (LDCV) docking and priming are identical to the corresponding reactions in synaptic vesicle (SV) exocytosis. Munc13s are essential for SV docking and priming, and we systematically analyzed their role in LDCV exocytosis using chromaffin cells lacking individual isoforms. We show that particularly Munc13-2 plays a fundamental role in LDCV exocytosis, but in contrast to synapses lacking Munc13s, the corresponding chromaffin cells do not exhibit a vesicle docking defect. We further demonstrate that ubMunc13-2 and Munc13-1 confer Ca(2+)-dependent LDCV priming with similar affinities, but distinct kinetics. Using a mathematical model, we identify an early LDCV priming step that is strongly dependent upon Munc13s. Our data demonstrate that the molecular steps of SV and LDCV priming are very similar while SV and LDCV docking mechanisms are distinct.