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.

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.

Urolithiasis, Urinary Cancer, and Home Drinking Water Source in the United States Territory of Guam, 2006-2010.

We reviewed patient records with a first-listed diagnosis of urolithiasis-also known as urinary tract or kidney stone disease, nephrolithiasis-upon discharge from Guam's sole civilian hospital during 2006 to 2010 and urinary cancer mortality records from the Guam Cancer Registry for 1970 to 2009 to determine the source of municipal water supplied to the patients' residence. The objective was to investigate a possible relationship between the sources of municipal water supplied to Guam villages and the incidence of urolithiasis and urinary cancer. We analyzed hospital discharge diagnoses of urolithiasis or renal calculi by calculating the incidence of first-mentioned discharge for urolithiasis or renal calculi and comparing rates across demographic or geographic categories while adjusting by age, sex, and ethnicity/race. We reviewed cancer registry records of urinary cancer deaths by patient residence. The annual incidence of hospitalization for urolithiasis was 5.22 per 10,000. Rates adjusted for sex or age exhibited almost no change. The rate of 9.83 per 10,000 among Chamorros was significantly higher (p < 0.05) than the rates among any other ethnic group or race. When villages were grouped by water source, rates of patients discharged with a first-listed diagnosis of urolithiasis, adjusted for ethnicity/race, were similar for villages using either well water (5.44 per 10,000) or mixed source water (5.39 per 10,000), and significantly greater than the rate for villages using exclusively reservoir water (1.35 per 10,000). No statistically significant differences were found between the water source or village of residence and urinary cancer mortality. Some Guam residents living in villages served completely or partly by deep well water high in calcium carbonate may be at increased risk for urolithiasis compared with residents living in villages served by surface waters. Although the risk appears to be highest in villagers of Chamorro ethnicity, residents should be aware of other contributing risk factors and steps to take to avoid developing this health problem.

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.

Social Support for Chamorro Breast Cancer Survivors on Guam.

PURPOSE: The purpose of this study was to assess the types of social support used by Chamorro (indigenous) breast cancer survivors on Guam. METHODS: We assessed social support use among 25 self-reported Chamorro women with a diagnosis of breast cancer through interviews and construction of genograms and ecomaps -pictorial displays of the women's family relationships, medical history, and their social networks. RESULTS: The mean age of the participants was 54.5 years. The average number of years since the diagnosis of breast cancer was 7.8 years. Respondents indicated that the nuclear family was the most important form of social support (34.2%). Indeed, nuclear family and other types of informal systems were the most common type of social support used by the women (60.2%). Formal support services, clubs, and organizations were reported by 17.9% of participants while spiritual and/or religious resources were reported by 21.9% of them. CONCLUSION: These Chamorro breast cancer survivors depended largely on family for social support. Support from family, although informal, should be recognized as a pivotal factor in recovery and survivorship. Future directions could incorporate formal and informal mechanisms to utilize this natural support resource.

Ethnic disparities in cancer incidence among residents of Guam.

Cancer incidence data collected by the Guam Cancer Registry for the period 1998 through 2002 were analyzed by cancer site, age, and ethnicity. Ethnicity and site specific age-adjusted cancer incidence rates for Guam residents were calculated utilizing Guam 2000 census data and the U.S. 2000 standard population and were compared to U.S. 2000 data. Age-adjusted total cancer incidence rates per 100,000 population for the major ethnic groups represented on Guam were generally lower than U.S. averages (the exception was the Caucasian group which was higher). Some highlights include: 1). Chamorros (the indigenous people of the Mariana Islands) living on Guam had a slightly lower total cancer incidence rate than the total U.S. population (406.8/100,000 vs. 478.6 U.S.). Chamorros had high age-adjusted incidence rates for cancers of the mouth and pharynx (24.4 vs. U.S. 10.7), nasopharynx (13.9 vs. 0.6 U.S.), liver (13.2 vs. 5.2 U.S.), and cervix (16.2 vs. 9.6 U.S.). Rates for prostate cancer ( 103.9 vs. 167.7 U.S.), female breast (115.9 vs. 130.9 U.S.), ovary (7.0 vs. 14.2 U.S.), colon-rectum-anus (44.3 vs. 56.9 U.S.), leukemia (11.0 vs. 12.6 U.S.), and non-Hodgkin lymphoma (7.0 vs. 18.9 U.S.) were all lower than U.S. rates. 2). Filipinos living on Guam had high age-adjusted incidence rates for cancers of the nasopharynx (5.1), and liver (9.6). Filipinos had low age-adjusted incidence rates for all cancers (215.7), cancers of the mouth and pharynx when NPC was excluded (4.8), lung and bronchus (35.6 vs. U.S. 70.1), pancreas (1.7 vs. U.S. 11.1), colon-rectum-anus (37.1), female breast (60.7), prostate (46.1), leukemia (4.7), and non-Hodgkin lymphoma (8.4). 3). Micronesians other than Chamorros had the highest age-adjusted incidence rates for cancers of the lung and bronchus (111.5), liver (39.4), and cervix (27.4). Micronesians had low age-adjusted incidence rates for cancers of the colon-rectum-anus (4.1), female breast (35.0), prostate (78.4), leukemia (6.3), and non-Hodgkin lymphoma (6.6). 4). Asians had low total age-adjusted cancer incidence rates (149.7) but had high nasopharyngeal cancer (5.4) and liver (10.7) cancer rates. Asians had low rates of cancers of the mouth and pharynx when nasopharyngeal cancers were excluded (1.4), lung and bronchus cancers (25.8), colon-rectum-anus (26.3), female breast (63.0), ovary (no cases recorded), prostate (31.3), leukemia (5.0) and non-Hodgkin lymphoma (4.9). 5).Caucasians residing on Guam had high age-adjusted cancer incidence rates for cancers of the colon-rectum-anus (91.4), female breast (148.6), ovary (34.7), and leukemia (17.7). Caucasians had low age-adjusted cancer incidence rates for nasopharyngeal cancer (no cases recorded), liver (4.0) and non-Hodgkin lymphoma (7.9). Suggestions are made for further research to explain the ethnic disparitiesin cancer incidence observed on Guam and to develop strategies for ameliorating these disparities.

Ethnic disparities in cancer mortality among residents of Guam.

Cancer mortality data collected by the Guam Cancer Registry for the period 1998 through 2002 were analyzed by cancer site, age, and ethnicity. Ethnicity and site specific age-adjusted cancer mortality rates for Guam were calculated utilizing Guam 2000 census data, the US 2000 standard population and compared to U.S. 2002 age-adjusted cancer mortality rates. Age-adjusted cancer mortality rates for ethnic populations represented on Guam, except those of leukemia and non-Hodgkins lymphoma, were high in relation to other population groups and higher than U.S. averages. Some highlights include: 1. Chamorros had high age-adjusted mortality rates for mouth and pharynx (15.5 vs. 2.7 [corrected] U.S.), nasopharynx (9.1 vs. 0.2 U.S.), lung and bronchus (66.9 vs. 54.9 U.S.), colon-rectum-anus (28.6 vs. 19.7 U.S.), breast (32.0 vs. 28.0 U.S.) and prostate cancer (40.9 vs. 27.9 U.S.); 2. Chamorros (6.4 vs. 2.5 U.S.) and Micronesians (6.3) had high and nearly identical age-adjusted mortality rates for cancer of the mouth and pharynx when nasopharyngeal cancers were excluded; 3. Micronesians had the highest mortality rate for liver cancer over all ethnicities documented (43.5 vs. 4.9 U.S.); 4. Asians had the highest mortality rates for pancreatic (12.5 vs. 10.5 U.S.) and cervical cancer (8.5 vs. 2.6 U.S.); 5. Caucasians had the highest mortality rates for leukemia (19.9 vs. 7.5 U.S.) and Non-Hodgkin's lymphoma (17.6 vs. 7.6 U.S.). Suggestions are made for further research on both explaining and ameliorating cancer mortality disparities among ethnic groups on Guam.

Oral cancer incidence disparity among ethnic groups on Guam.

Although the prevalence of betel nut use among Chamorro residents of Guam is higher than that of other Micronesians residing on the island, the "other Micronesian" ethnic groups have a mouth cancer incidence rate more than double that of Chamorros. The reason for this apparent disparity in rates of mouth cancer incidence may be clarified by future studies focused on the frequency and method of betel nut use among these populations. Another possible explanation for this apparent disparity in cancer incidence rates could be that of migration to Guam for medical treatment.

Cancer in the Territory of Guam.

The purpose of this study, funded by the National Cancer Institute, was to assess cancer awareness and service needs in Guam. Guam maintains a cancer registry, and data suggest that cancer is the second-leading cause of death in Guam. A chapter of the American Cancer Society has been established on the island. Although basic cancer diagnosis and treatment services can be provided on Guam, many cancer patients must travel to Hawai'i, the U.S. continent, or to Asian countries to seek more advanced medical care. This places a severe strain on the island's limited financial resources that, in turn, affects all aspects of health care for the people of Guam. Key informants identified a number of cancer-related service needs, and an action plan was developed based on five priority areas: 1) increasing the capacity of cancer prevention and control staff; 2) increasing public awareness of cancer risk factors; 3) expanding the capacity of the Guam Cancer Registry; 4) establishing a Cancer Prevention and Control Advisory Board for the Territory; and 5) improving early detection and screening for priority cancers.

Cancer on Guam, especially among Micronesians.

The Guam Cancer Registry (GCR) collects data on cases of cancer in Guam residents whether their initial diagnosis is made on Guam or as a result of a referral to an off-island medical facility. It also collects data on cancer of non-residents diagnosed on Guam. Although including non-Guam resident cancer cases in statistical tables will have the effect of raising local cancer rates, this probably only partially compensates for the number of Guam-resident cancer cases that are diagnosed off-island and not reported to the registry. Cases are also collected by a periodic review of death certificates filed with the Guam Office of Vital Statistics. To test this hypothesis GCR records were reviewed to determine the number of reported cancer cases for each ethnic group that claimed to be Guam residents. Since a high proportion of cancers seen among Micronesians on Guam represent cases referred from their home islands, it may also be that these cases only represent those cancers most likely to be referred to Guam rather than being representative of the cancers most commonly occurring within these ethnic groups in their home islands.