Suzanne P. Moore

Association of Helicobacter pylori Infection With Reduced Risk for Esophageal Cancer Is Independent of Environmental and Genetic Modifiers

BACKGROUND & AIMS Infection with Helicobacter pylori is associated with reduced risk of esophageal adenocarcinoma (EAC), but it is not clear whether this reduction is modified by genotype, other host characteristics, or environmental factors. Furthermore, little is known about the association between H pylori and adenocarcinomas of the esophagogastric junction (EGJAC) or squamous cell carcinomas (ESCC). We sought to measure the association between H pylori infection and esophageal cancer and identify potential modifiers. METHODS In an Australian, population-based, case-control study, we compared the prevalence of H pylori seropositivity and single nucleotide polymorphisms in interleukin (IL)-1B (-31, -511) and tumor necrosis factor (TNF)-alpha (-308, -238) among 260 EAC, 298 EGJAC, and 208 ESCC patients and 1346 controls. To estimate relative risks, we calculated odds ratios (OR) and 95% confidence intervals (CI) using multivariable logistic regression in the entire sample and within strata of phenotypic and genotypic risk factors. RESULTS H pylori infection was associated with significantly reduced risks of EAC (OR, 0.45; 95% CI: 0.30-0.67) and EGJAC (OR, 0.41; 95% CI: 0.27-0.60) but not ESCC (OR, 1.04; 95% CI: 0.71-1.50). For each cancer subtype, risks were of similar magnitude across strata of reflux frequency and smoking status. We found no evidence that polymorphisms in IL-1B or TNF-alpha modified the association between H pylori and EAC or EGJAC. CONCLUSIONS H pylori infection is inversely associated with risks of EAC and EGJAC (but not ESCC); the reduction in risk is similar across subgroups of potential modifiers.

Serous ovarian, fallopian tube and primary peritoneal cancers: A comparative epidemiological analysis

Invasive serous cancers are diagnosed in the ovary, fallopian tube and peritoneum. It is widely believed that these are variants of the same malignancy but little is known about fallopian tube and primary peritoneal cancers. A comparison of risk factors for these tumor types may shed light on common or distinct aetiological pathways involved in these types of cancer. We investigated risk factors for the three cancers using data from a large Australian population‐based case‐control study. We included women with incident invasive serous ovarian (n = 627), primary peritoneal (n = 129) and fallopian tube (n = 45) cancer and 1,508 control women. Participants completed a comprehensive reproductive and lifestyle questionnaire. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Hormonal contraceptive use was inversely related to risk of all three cancers. Parity and breast‐feeding were also inversely related to risk of serous ovarian and fallopian tube cancer. In contrast, parous women had an increased risk of peritoneal cancer (OR = 1.8, 95%CI 0.8–3.9), and increasing parity did not lower risk. There was also no association between breast‐feeding and peritoneal cancer. However, obesity was associated with a doubling of risk for peritoneal cancer alone (OR = 2.1, 95%CI = 1.3–3.4). The strikingly similar patterns of risk for serous ovarian and fallopian tube cancers and the somewhat different results for primary peritoneal cancer suggest that peritoneal cancers may develop along a different pathway. These results also call into question the role of the physical effects of ovulation in the development of serous ovarian cancer.

The burden of stomach cancer in indigenous populations: a systematic review and global assessment

Objective Stomach cancer is a leading cause of cancer death, especially in developing countries. Incidence has been associated with poverty and is also reported to disproportionately affect indigenous peoples, many of whom live in poor socioeconomic circumstances and experience lower standards of health. In this comprehensive assessment, we explore the burden of stomach cancer among indigenous peoples globally. Design The literature was searched systematically for studies on stomach cancer incidence, mortality and survival in indigenous populations, including Indigenous Australians, Maori in New Zealand, indigenous peoples from the circumpolar region, native Americans and Alaska natives in the USA, and the Mapuche peoples in Chile. Data from the New Zealand Health Information Service and the Surveillance Epidemiology and End Results (SEER) Program were used to estimate trends in incidence. Results Elevated rates of stomach cancer incidence and mortality were found in almost all indigenous peoples relative to corresponding non-indigenous populations in the same regions or countries. This was particularly evident among Inuit residing in the circumpolar region (standardised incidence ratios (SIR) males: 3.9, females: 3.6) and in Maori (SIR males: 2.2, females: 3.2). Increasing trends in incidence were found for some groups. Conclusions We found a higher burden of stomach cancer in indigenous populations globally, and rising incidence in some indigenous groups, in stark contrast to the decreasing global trends. This is of major public health concern requiring close surveillance and further research of potential risk factors. Given evidence that improving nutrition and housing sanitation, and Helicobacter pylori eradication programmes could reduce stomach cancer rates, policies which address these initiatives could reduce inequalities in stomach cancer burden for indigenous peoples.

Cancer incidence in indigenous people in Australia, New Zealand, Canada, and the USA: a comparative population-based study

INTRODUCTION Indigenous people have disproportionally worse health and lower life expectancy than their non-indigenous counterparts in high-income countries. Cancer data for indigenous people are scarce and incidence has not previously been collectively reported in Australia, New Zealand, Canada, and the USA. We aimed to investigate and compare, for the first time, the cancer burden in indigenous populations in these countries. METHODS We derived incidence data from population-based cancer registries in three states of Australia (Queensland, Western Australia, and the Northern Territory), New Zealand, the province of Alberta in Canada, and the Contract Health Service Delivery Areas of the USA. Summary rates for First Nations and Inuit in Alberta, Canada, were provided directly by Alberta Health Services. We compared age-standardised rates by registry, sex, cancer site, and ethnicity for all incident cancer cases, excluding non-melanoma skin cancers, diagnosed between 2002 and 2006. Standardised rate ratios (SRRs) and 95% CIs were computed to compare the indigenous and non-indigenous populations of each jurisdiction, except for the Alaska Native population, which was compared with the white population from the USA. FINDINGS We included 24 815 cases of cancer in indigenous people and 5 685 264 in non-indigenous people from all jurisdictions, not including Alberta, Canada. The overall cancer burden in indigenous populations was substantially lower in the USA except in Alaska, similar or slightly lower in Australia and Canada, and higher in New Zealand compared with their non-indigenous counterparts. Among the most commonly occurring cancers in indigenous men were lung, prostate, and colorectal cancer. In most jurisdictions, breast cancer was the most common cancer in women followed by lung and colorectal cancer. The incidence of lung cancer was higher in indigenous men in all Australian regions, in Alberta, and in US Alaska Natives than in their non-indigenous counterparts. For breast cancer, rates in women were lower in all indigenous populations except in New Zealand (SRR 1·23, CI 95% 1·16-1·32) and Alaska (1·14, 1·01-1·30). Incidence of cervical cancer was higher in indigenous women than in non-indigenous women in most jurisdictions, although the difference was not always statistically significant. INTERPRETATION There are clear differences in the scale and profile of cancer in indigenous and non-indigenous populations in Australia, New Zealand, Canada, and the USA. Our findings highlight the need for much-improved, targeted programmes of screening, vaccination, and smoking cessation, among other prevention strategies. Governments and researchers need to work in partnership with indigenous communities to improve cancer surveillance in all jurisdictions and facilitate access to cancer data. FUNDING International Agency for Research on Cancer-Australia Fellowship.

Survival disparities in Australia: an analysis of patterns of care and comorbidities among indigenous and non-indigenous cancer patients

BackgroundIndigenous Australians have lower overall cancer survival which has not yet been fully explained. To address this knowledge deficit, we investigated the associations between comorbidities, cancer treatment and survival in Indigenous and non-Indigenous people in Queensland, Australia.MethodsA cohort study of 956 Indigenous and 869 non-Indigenous patients diagnosed with cancer during 1998–2004, frequency-matched on age, sex, remoteness of residence and cancer type, and treated in Queensland public hospitals. Survival after cancer diagnosis, and effect of stage, treatment, and comorbidities on survival were examined using Cox proportional hazard models.ResultsOverall Indigenous people had more advanced cancer stage (p = 0.03), more comorbidities (p < 0.001), and received less cancer treatment (77% vs. 86%, p = 0.001). Among patients without comorbidities and social disadvantage, there was a lower uptake of treatment among Indigenous patients compared to non-Indigenous patients. For those who received treatment, time to commencement, duration and dose of treatment were comparable. Unadjusted cancer survival (HR = 1.30, 95% CI 1.15-1.48) and non-cancer survival (HR = 2.39, 95% CI 1.57-3.63) were lower in the Indigenous relative to non-Indigenous patients over the follow-up period. When adjusted for clinical factors, there was no difference in cancer-specific survival between the groups (HR = 1.10, 95% CI 0.96-1.27). One-year survival was lower for Indigenous people for all-causes of death (adjusted HR = 1.33, 95% CI 1.12-1.83).ConclusionIn this study, Indigenous Australians received less cancer treatment, had more comorbidities and had more advanced cancer stage at diagnosis, factors which contribute to poorer cancer survival. Moreover, for patients with a more favourable distribution of such prognostic factors, Indigenous patients received less treatment overall relative to non-Indigenous patients. Personalised cancer care, which addresses the clinical, social and overall health requirements of Indigenous patients, may improve their cancer outcomes.

Cancer in indigenous people in Latin America and the Caribbean: a review

Cancer is a leading cause of death in Latin America but there have been few assessments of the cancer burden for the 10% of the population who are indigenous. Evidence from other world regions suggests cancer survival is poorer for indigenous people than for others due to a greater incidence of case‐fatal cancers, later stage at diagnosis, and less cancer treatment. A status report on the cancer profile of indigenous people in Latin America and the Caribbean (LAC) is therefore clearly warranted. We undertook a systematic review of the peer‐reviewed literature in academic databases, and considered evidence from cancer registries from 1980, to assess cancer epidemiology among indigenous people in LAC. We identified 35 peer‐reviewed articles pertaining to cancer in indigenous people. Rates of cervical cancer in parts of Brazil, Ecuador, and Guyana, stomach cancer rates in regions of Chile and gallbladder rates in Chile and Bolivia, were higher for indigenous compared to others. Breast cancer rates were lower in Ecuador, Brazil, and Chile. Six cancer registries in Brazil provided incidence data but no other reports of incidence, mortality, or survival were identified. There was a paucity of data surrounding the cancer burden of indigenous people in LAC. In view of predicted increases in cancer rates in ensuing decades, and the disparities in burden already experienced by indigenous people in the region, it is imperative that cancer profiles are obtained and cancer control measures identified and prioritized.

A study of head and neck cancer treatment and survival among indigenous and non-indigenous people in Queensland, Australia, 1998 to 2004

BackgroundOverall, Indigenous Australians with cancer are diagnosed with more advanced disease, receive less cancer treatment and have poorer cancer survival than non-Indigenous Australians. The prognosis for Indigenous people with specific cancers varies however, and their prognosis for cancers of the head and neck is largely unknown. We therefore have compared clinical characteristics, treatment and survival between Indigenous and non-Indigenous people diagnosed with head and neck cancer in Queensland, Australia.MethodsRates were based on a cohort of Indigenous people (n = 67), treated in public hospitals between 1998 and 2004 and frequency-matched on age and location to non-Indigenous cases (n = 62) also treated in the public health system. Data were obtained from hospital records and the National Death Index. We used Pearsons Chi-squared analysis to compare categorical data (proportions) and Cox proportional hazard models to assess survival differences.ResultsThere were no significant differences in socioeconomic status, stage at diagnosis or number and severity of comorbidities between Indigenous and non-Indigenous patients, although Indigenous patients were more likely to have diabetes. Indigenous people were significantly less likely to receive any cancer treatment (75% vs. 95%, P = 0.005) and, when cancer stage, socioeconomic status, comorbidities and cancer treatment were taken into account, they experienced greater risk of death from head and neck cancer (HR 1.88, 1.10, 3.22) and from all other causes (HR 5.83, 95% CI 1.09, 31.04).ConclusionThese findings show for the first time that Indigenous Australians with head and neck cancer receive less cancer treatment and suggest survival disparity could be reduced if treatment uptake was improved. There is a need for a greater understanding of the reasons for such treatment and survival disparities, including the impact of the poorer overall health on cancer outcomes for Indigenous Australians.

International variations in childhood cancer in indigenous populations: A systematic review

Although the cancer burden in indigenous children has been reported in some countries, up to now, no international comparison has been made. We therefore aimed to assess the available evidence of the burden of childhood cancer in indigenous populations. We did a systematic review of reports on cancer incidence, mortality, and survival in indigenous children worldwide. Our findings highlight the paucity of accessible information and advocate the pressing need for data by indigenous status in countries where population-based cancer registries are established. The true extent of disparities between the burden in the indigenous community needs to be measured so that targeted programmes for cancer control can be planned and implemented.

Cervical Abnormalities Are More Common among Indigenous than Other Australian Women: A Retrospective Record-Linkage Study, 2000-2011.

Indigenous Australian women have much higher incidence of cervical cancer compared to non-Indigenous women. Despite an organised cervical screening program introduced 25 years ago, a paucity of Indigenous-identified data in Pap Smear Registers remains. Prevalence of cervical abnormalities detected among the screened Indigenous population has not previously been reported. We conducted a retrospective cohort study of population-based linked health records for 1,334,795 female Queensland residents aged 20–69 years who had one or more Pap smears during 2000–2011; from linked hospital records 23,483 were identified as Indigenous. Prevalence was calculated separately for Indigenous and non-Indigenous women, for cytology-detected low-grade (cLGA) and high-grade abnormalities (cHGA), and histologically confirmed high-grade abnormalities (hHGA). Odds ratios (OR) were estimated from logistic regression analysis. In 2010–2011 the prevalence of hHGA among Indigenous women (16.6 per 1000 women screened, 95% confidence interval [CI] 14.6–18.9) was twice that of non-Indigenous women (7.5 per 1000 women screened, CI 7.3–7.7). Adjusted for age, area-level disadvantage and place of residence, Indigenous women had higher prevalence of cLGA (OR 1.4, CI 1.3–1.4), cHGA (OR 2.2, CI 2.1–2.3) and hHGA (OR 2.0, CI 1.9–2.1). Our findings show that Indigenous women recorded on the Pap Smear Register have much higher prevalence for cLGA, cHGA and hHGA compared to non-Indigenous women. The renewed cervical screening program, to be implemented in 2017, offers opportunities to reduce the burden of abnormalities and invasive cancer among Indigenous women and address long-standing data deficiencies.

The first comprehensive report on Indigenous Australian women's inequalities in cervical screening: A retrospective registry cohort study in Queensland, Australia (2000‐2011)

The Australian National Cervical Screening Program, introduced more than 20 years ago, does not record the Indigenous status of screening participants. This article reports the first population‐based estimates of participation in cervical screening for Indigenous and non‐Indigenous Australian women.