Incidence of Etiology-specific Hepatocellular Carcinoma: Diverging Trends and Significant Heterogeneity by Race and Ethnicity

BACKGROUND & AIMS

The main causes of hepatocellular carcinoma (HCC) include chronic hepatitis C and B viral infections (HCV, HBV), nonalcoholic fatty liver disease (NAFLD), and alcohol-related disease (ALD). Etiology-specific HCC incidence rates and temporal trends on a population-basis are needed to improve HCC control and prevention.

METHODS

All 14,420 HCC cases from the Florida statewide cancer registry were individually linked to data from the hospital discharge agency and the viral hepatitis department to determine the predominant etiology of each case diagnosed during 2010 to 2018. Age-adjusted incidence rates (AAIRs) were used to assess the intersection between etiology and detailed race-ethnicity. Etiology-specific temporal trends based on diagnosis year were assessed using Joinpoint regression.

RESULTS

HCV remains the leading cause of HCC among men, but since 2017 NAFLD-HCC is the leading cause among women. HCV-HCC AAIRs are particularly high among U.S.-born minority men, including Puerto Rican (10.9 per 100,000), African American (8.0 per 100,000), and U.S.-born Mexican American men (7.6 per 100,000). NAFLD is more common among all Hispanics and Filipinos and HBV-HCC among Asian and Haitian black men. HCV-HCC surpasses HBV-HCC in Asian women. ALD-HCC is high among specific Hispanic male groups. Population-based HCV-HCC rates experienced a rapid decline since 2015 (-9.6% annually), whereas ALD-HCC (+6.0%) and NAFLD-HCC (+4.3%) are rising (P < .05).

CONCLUSIONS

New direct acting anti-viral drugs have impacted rates of HCV-HCC, offsetting important increases in both ALD- and NAFLD-HCC. Hispanics may be a group of concern because of higher rates for ALD- and NAFLD-HCC. HCC etiology varies remarkably and may warrant specific interventions by detailed race-ethnicity.

The prognostic role of cigarette smoking in Kidney Cancer Survival

BACKGROUND

The role of cigarette smoking as a prognostic factor for kidney cancer (KC) is unclear. In this population-based study, we analyze cancer-specific survival (CSS) outcomes among KC patients by smoking status at diagnosis in the diverse state of Florida.

METHODS

All primary KC cases from the Florida Cancer Registry diagnosed during 2005-2018 were analyzed. Cox proportional regression was conducted to assess the determinants of KC survival, including age, sex, race/ethnicity, socioeconomic status, histology type, cancer stage, and treatment received with a particular focus on smoking status (smokers at diagnosis referred to as current smokers, former smokers, and never smokers).

RESULTS

Among all 36,150 KC patients, 18.3% were smokers at diagnosis (n = 6629), 32.9% were former smokers (n = 11,870), and 48.8% were never smokers (n = 17,651). Age-standardized five-year survival for current, former, and never smokers was 65.3 (95% CI: 64.1-66.5), 70.6 (95% CI: 69.7-71.5), and 75.3 (95% CI: 74.6-76.0) respectively. In multivariable analysis, current and former smokers had an estimated 30% and 14% higher risk of KC death compared to never smokers, respectively, after adjusting for potential confounders (HR: 1.30, 95% CI: 1.23-1.40; HR: 1.14, 95% CI: 1.10-1.20).

CONCLUSION

Smoking independently contributes to poorer survival, across all KC stages. Clinicians should encourage and facilitate participation in cigarette smoking cessation programs targeted at current smokers. Prospective studies are warranted to assess the role of different types of tobacco use and cessation programs on KC survival.

Lung Cancer Incidence by Detailed Race-Ethnicity

Lung cancer (LC) incidence rates and tumor characteristics among (non-Hispanic) Black and Hispanic detailed groups, normally characterized in aggregate, have been overlooked in the US. We used LC data from the Florida state cancer registry, 2012-2018, to compute LC age-adjusted incidence rates (AAIR) for US-born Black, Caribbean-born Black, Mexican, Puerto Rican, Cuban, Dominican, and Central and South American populations. We analyzed 120,550 total LC cases. Among Hispanics, Cuban males had the highest AAIR (65.6 per 100,000; 95%CI: 63.6-67.6), only 8% [Incidence Rate Ratio (IRR): 0.92; 95%CI: 0.89-0.95] lower than Whites, but 2.7 (IRR 95%CI: 2.31-3.19) times higher than Central Americans. Among Blacks, the AAIR for US-born Black males was over three times that of those Caribbean-born (IRR: 3.12; 95%CI: 2.80-3.40) and 14% higher than White males (IRR: 1.14; 95%CI: 1.11-1.18). Among women, US-born Blacks (46.4 per 100,000) and foreign-born Mexicans (12.2 per 100,000) had the highest and lowest rates. Aggregation of non-Hispanic Blacks or Hispanics obscures inherent disparities within groups. Understanding the distinct LC rates in US populations is crucial for targeting public health measures for LC diagnosis, prevention, and treatment. Further LC research exploring detailed race-ethnicity regarding LC in never-smokers is necessary, particularly among females and considering pertinent environmental factors.

Seroprevalence, distribution, and risk factors for human leptospirosis in the United States Virgin Islands

Background

The first documented human leptospirosis cases in the U.S. Virgin Islands (USVI) occurred following 2017 Hurricanes Irma and Maria. We conducted a representative serosurvey in USVI to estimate the seroprevalence and distribution of human leptospirosis and evaluate local risk factors associated with seropositivity.

Methodology/Principal findings

A stratified, two-stage cluster sampling design was used and consisted of three island strata and random selection of census blocks and then households. All eligible members of selected households were invited to participate (≥5 years old, resided in USVI ≥6 months and ≥6 months/year). Household and individual-level questionnaires were completed, and serum collected from each enrolled individual. Microscopic agglutination test serology was conducted, and bivariate and logistic regression analyses completed to identify risk factors for seropositivity.

In March 2019, 1,161 individuals were enrolled from 918 households in St. Croix, St. Thomas, and St. John. The territory-wide weighted seroprevalence was 4.0% (95% CI:2.3–5.7). Characteristics/exposures independently associated with seropositivity using logistic regression included contact with cows (OR: 39.5; 95% CI: 9.0–172.7), seeing rodents/rodent evidence or contact with rodents (OR: 2.6; 95% CI: 1.1–5.9), and increasing age (OR: 1.02; 95% CI: 1.002–1.04); full or partial Caucasian/White race was negatively correlated with seropositivity (OR: 0.02, 95% CI: 0.04–0.7). Bivariate analysis showed self-reported jaundice since the 2017 hurricanes (pRR: 5.7; 95% CI: 1.0–33.4) was associated with seropositivity and using a cover/lid on cisterns/rainwater collection containers (pRR: 0.3; 95% CI: 0.08–0.8) was protective against seropositivity.

Conclusions/Significance

Leptospirosis seropositivity of 4% across USVI demonstrates an important human disease that was previously unrecognized and emphasizes the importance of continued leptospirosis surveillance and investigation. Local risk factors identified may help guide future human and animal leptospirosis studies in USVI, strengthen leptospirosis public health surveillance and treatment timeliness, and inform targeted education, prevention, and control efforts.

Assessing rodents as carriers of pathogenic Leptospira species in the U.S. Virgin Islands and their risk to animal and public health

Leptospirosis is a global zoonotic disease caused by pathogenic bacteria of the genus Leptospira. We sought to determine if rodents in U.S. Virgin Islands (USVI) are carriers of Leptospira. In total, 140 rodents were sampled, including 112 Mus musculus and 28 Rattus rattus. A positive carrier status was identified for 64/140 (45.7%); 49 (35.0%) were positive by dark-field microscopy, 60 (42.9%) by culture, 63 (45.0%) by fluorescent antibody testing, and 61 (43.6%) by real-time polymerase chain reaction (rtPCR). Molecular typing indicated that 48 isolates were L. borgpetersenii and 3 were L. kirschneri; the remaining nine comprised mixed species. In the single culture-negative sample that was rtPCR positive, genotyping directly from the kidney identified L. interrogans. Serotyping of L. borgpetersenii isolates identified serogroup Ballum and L. kirschneri isolates as serogroup Icterohaemorrhagiae. These results demonstrate that rodents are significant Leptospira carriers and adds to understanding the ecoepidemiology of leptospirosis in USVI.

Mongooses (Urva auropunctata) as reservoir hosts of Leptospira species in the United States Virgin Islands, 2019-2020

During 2019-2020, the Virgin Islands Department of Health investigated potential animal reservoirs of Leptospira spp., the bacteria that cause leptospirosis. In this cross-sectional study, we investigated Leptospira spp. exposure and carriage in the small Indian mongoose (Urva auropunctata, syn: Herpestes auropunctatus), an invasive animal species. This study was conducted across the three main islands of the U.S. Virgin Islands (USVI), which are St. Croix, St. Thomas, and St. John. We used the microscopic agglutination test (MAT), fluorescent antibody test (FAT), real-time polymerase chain reaction (lipl32 rt-PCR), and bacterial culture to evaluate serum and kidney specimens and compared the sensitivity, specificity, positive predictive value, and negative predictive value of these laboratory methods. Mongooses (n = 274) were live-trapped at 31 field sites in ten regions across USVI and humanely euthanized for Leptospira spp. testing. Bacterial isolates were sequenced and evaluated for species and phylogenetic analysis using the ppk gene. Anti-Leptospira spp. antibodies were detected in 34% (87/256) of mongooses. Reactions were observed with the following serogroups: Sejroe, Icterohaemorrhagiae, Pyrogenes, Mini, Cynopteri, Australis, Hebdomadis, Autumnalis, Mankarso, Pomona, and Ballum. Of the kidney specimens examined, 5.8% (16/270) were FAT-positive, 10% (27/274) were culture-positive, and 12.4% (34/274) were positive by rt-PCR. Of the Leptospira spp. isolated from mongooses, 25 were L. borgpetersenii, one was L. interrogans, and one was L. kirschneri. Positive predictive values of FAT and rt-PCR testing for predicting successful isolation of Leptospira by culture were 88% and 65%, respectively. The isolation and identification of Leptospira spp. in mongooses highlights the potential role of mongooses as a wildlife reservoir of leptospirosis; mongooses could be a source of Leptospira spp. infections for other wildlife, domestic animals, and humans.

Determination of freedom-from-rabies for small Indian mongoose populations in the United States Virgin Islands, 2019-2020

Mongooses, a nonnative species, are a known reservoir of rabies virus in the Caribbean region. A cross-sectional study of mongooses at 41 field sites on the US Virgin Islands of St. Croix, St. John, and St. Thomas captured 312 mongooses (32% capture rate). We determined the absence of rabies virus by antigen testing and rabies virus exposure by antibody testing in mongoose populations on all three islands. USVI is the first Caribbean state to determine freedom-from-rabies for its mongoose populations with a scientifically-led robust cross-sectional study. Ongoing surveillance activities will determine if other domestic and wildlife populations in USVI are rabies-free.

Mongooses in the Caribbean region are known to carry rabies and infect and kill humans with the deadly virus. While many countries in the Caribbean region assume they are rabies-free, there is a lack of scientifically based surveillance. We prospectively designed a statistically valid study to determine that mongoose populations in the US Virgin Islands are rabies-free and pose no risk of transmission to human or animal populations. We are pursuing further surveillance efforts to establish rabies freedom in all wildlife and domestic animal population in the US Virgin Islands.