Ethnic disparities in early-onset colorectal cancer incidence, screening rates and risk factors prevalence in Guam.

Objective: Colorectal cancer (CRC) is one of the four most common cancers and the third leading cause of cancer-related deaths in Guam. This study investigated CRC incidence, screening, and risk factors of early onset CRC across Guam's ethnic groups using data from the Guam Cancer Registry (1998-2020) and the Guam Behavioral Risk Factor Surveillance System (2018-2019). Methods: Incidence rate ratios (IRRs) were calculated to compare incidence rates across different age groups stratified by sex, ethnicity, and stage. Incidence rate differences (IRDs) were used to test for significant differences across sex and ethnicity. The Pearson chi-square test was used to assess differences in CRC screening rates by age, sex, education, income, healthcare coverage, and ethnicity, and to examine ethnic group disparities in the prevalence of CRC risk factors. Results: The steepest increase in CRC incidence was observed between the 35-39 and 40-44 age groups (IRR = 2.01; 95 % CI: 1.14-3.53) and between the 40-44 and 45-49 age groups (IRR = 1.99; 95 % CI: 1.34-2.97). CHamorus exhibited rate increases at younger ages compared to Filipinos. CRC screening prevalence and associated risk factors showed considerable variation among ethnicities. Conclusions: Elevated early-onset CRC rates were observed for both CHamorus and the broader Guam population under 50. The findings support the new recommendation to begin screening at age 45 and efforts to increase screening in Guam.

Disparities in Colorectal Cancer Incidence among Asian and Pacific Islander Populations in Guam, Hawai'i, and the United States.

Colorectal cancer (CRC) ranks among the three most common cancers in Guam (GU), Hawai'i (HI), and the mainland United States (US). CRC prevalence in these areas is high among Filipinos, and indigenous CHamorus and Native Hawaiians; however, data on these populations are frequently aggregated in epidemiological studies, which can mask true CRC disparities. We examined CRC cumulative incidence rates (CIRs) among CHamorus in GU, Filipinos in GU, HI, and the US, and Native Hawaiians in HI and the US. CRC CIRs were calculated for two age groups (20-49 years; early onset, and 50-79 years; senior) and four time periods (2000-2004, 2005-2009, 2010-2014, and 2015-2019), stratified by ethnicity, sex, and location. Data analyzed included all invasive CRC cases reported to the Surveillance, Epidemiology, and End Results 9-Registry (n = 166,666), the Hawai'i Tumor Registry (n = 10,760), and the Guam Cancer Registry (n = 698) between 2000 and 2019. Senior CIRs were highest in HI and lowest in GU throughout all time periods, with a downward trend observed for senior CIRs in the US and HI, but not GU. This downward trend held true for all ethnic groups, except for CHamorus in GU, females in GU, and females of CHamoru ethnicity in GU. In contrast, early onset CIRs increased across all locations, sexes, and ethnic groups, except for Filipinos in HI and males of Filipino ethnicity in HI. Our findings provide crucial insights for future research and policy development aimed at reducing the burden of CRC among indigenous populations.

Cumulative Incidence Rates of Breast Cancer by Age for Filipinos and Chamorros in Guam.

Breast cancer is the second leading cause of cancer-related death among women on Guam and Hawai'i. Breast cancer incidence rates are described here for the multiethnic population in Guam, a United States (US) Pacific island territory, and compared to Hawai'i and other US populations, to understand the risk by age and race/ethnic group in this understudied group. The study included all breast cancer cases (n=576) reported to the Guam Cancer Registry, all breast cancer cases (n=8345) reported to the Hawai'i Tumor Registry and all breast cancer cases (n=678,637) reported to the Surveillance, Epidemiology, and End Results program from 2000 to 2009. Cumulative incidence rates by age were calculated for two time periods: 2000-2004 and 2005-2009. Differences were seen in cumulative incidence rates by age, ethnicity, and place of residence. Cumulative incidence rates by age 40 were the highest (0.7%) among Filipinos in Guam but, after age 40, the rates for Chamorros (indigenous Pacific Islanders of Guam) increased rapidly. The lifetime cumulative incidence rates were the highest for Chamorros in Guam (15.3%), close to the US rate (15.5%). Results were similar for 2005-2009. Women in Guam are at high risk for breast cancer, with the indigenous Chamorros having the highest risk, and the most prevalent Asian group of Filipinos, having a younger age at diagnosis. These patterns are similar to the comparable Pacific Islander and Filipino populations in Hawai'i and the US generally.

Together we can: Collaborative Efforts to Reduce the Cancer Burden on Guam and Save Lives.

Cancer remains the second leading cause of death for Guamanians. Guam Cancer Registry (GCR) for two decades has provided epidemiological and demographic data needed to understand the unique cancer burden in Guam. Cancer data, along with data on behavioral risk factors and screening, have helped public health practitioners to target areas of need in cancer prevention, control, and research for Guam and our Pacific neighbors. These targeted efforts enable efficient use of limited resources. While cancer in its many forms remains a formidable foe, we now have a toolbox of evidence-based interventions (EBI), culturally-appropriate programs, community-based coalitions, and research unique to our region. Quality cancer data will remain a key component of this toolbox. This paper reports on the most recent cancer data for Guam for 2007-2015, and Guam's progress toward finding a "cure for cancer" through screening, early detection and treatment, and local research. Together, we can.

The use of tobacco tax revenues to fund the Guam Cancer Registry: A double win for cancer control.

Cancer registries that provide reliable data on cancer incidence, mortality and burden are essential to cancer control. However, establishing sustainable local funding mechanisms to support cancer registries remains a challenge in many countries. Guam, an unincorporated Territory of the United States of America in the Western Pacific, enacted a bill that raised tobacco taxes, and earmarked a percentage of tobacco tax revenues to support its Cancer Registry. This provided a reliable funding stream for the Registry, allowing for continued staffing and capacity building; at the same time, youth tobacco consumption decreased following the tax increase. Linking tobacco tax revenues to cancer registry support is a feasible strategy with a double benefit: higher tobacco prices from higher tobacco taxes reduce tobacco-related cancer risk while assuring the long-term viability of systematic cancer data collection and dissemination.

Cancer in Guam and Hawaii: A comparison of two U.S. Island populations.

BACKGROUND: Cancer disparities within and across populations provide insight into the influence of lifestyle, environment, and genetic factors on cancer risk. METHODS: Guam cancer incidence and mortality were compared to that of Hawaii using data from their respective population-based, central cancer registries. RESULTS: In 2009-2013, overall cancer incidence was substantially lower in Guam than in Hawaii for both sexes while overall cancer mortality was higher for Guam males. Cervical cancer incidence and prostate cancer mortality were higher in Guam. Both incidence and mortality were higher among Guam men for cancers of the lung & bronchus, liver & intrahepatic bile duct, and nasopharynx; Chamorro men were disproportionately affected by these cancers. Filipinos and Whites in Guam had lower overall cancer incidence compared to Filipinos and Whites in Hawaii. Although breast cancer incidence was significantly lower in Guam compared to Hawaii, women in Guam presented at younger ages and with rarer disease histologies such as inflammatory carcinoma were more prevalent. Guam patients were also diagnosed at younger ages for cancers of bladder, pancreas, colon & rectum, liver & intrahepatic bile duct, lung & bronchus, stomach, non-Hodgkin lymphoma, and leukemia. CONCLUSION: Smoking, infectious agents, and betel nut chewing appear to be important contributors to the burden of cancer in Guam. Earlier onset of cancer in Guam suggests earlier age of exposure to key risk factors and/or a more aggressive pathogenesis. Contrasting cancer patterns within Guam and between Guam and Hawaii underscore the potential influence of genes, lifestyle, and environmental factors on cancer development and progression.

Cancer mortality following polychlorinated biphenyl (PCB) contamination of a Guam village.

UNLABELLED: Beginning more than 10 years after the release of polychlorinated biphenyl (PCB) contamination in the favored fishing grounds of Merizo village, an increase in the proportional cancer mortality rate was observed among residents of the village. This increased rate continued for approximately 20 years after which it returned to near island-wide Guam levels. Although the temporal association between PCB contamination of the environment of this village and an increase in cancer mortality is intriguing, it does not necessarily demonstrate a cause and effect relationship. OBJECTIVE: To investigate a possible temporal relationship between PCB contamination of the Cocos Lagoon and cancer deaths in the adjoining village of Merizo. METHODS: Data utilized in the study included deaths recorded by the Guam Cancer Registry (years 2000 to 2007) and data collected from original death certificates (years 1968-1999). To check whether there was a significant difference in the proportion of deaths due to cancer in Merizo compared with the rest of Guam, deaths were grouped in four 10-year periods, 1968-1977, 1978-1987, 1988-1997, and 1998-2007, and the Pearson Chi-Square test was calculated for each period separately RESULTS: While the number of new cancer cases recorded in the village of Merizo were insufficient in number to draw a statistically significant conclusion when single year incidence rates were compared to the rest of the island, a proportional mortality study showed a distinct increase for the village of Merizo compared to other villages for the period 1978-1997. CONCLUSION: While it is not possible to conclude with certainty that PCB contamination of the Cocos Lagoon was responsible for the observed increase in the proportion of cancer deaths in Merizo village beginning during the 10-year period 1978-1987, that increase and the subsequent decrease as PCB levels also decreased presents the possibility that these trends may be related.