Time to clinical investigation for Indigenous and non-Indigenous Queensland women after a high grade abnormal Pap smear, 2000-2009.

OBJECTIVES: To investigate time to follow-up (clinical investigation) for Indigenous and non-Indigenous women in Queensland after a high grade abnormality (HGA) being detected by Pap smear. DESIGN, SETTING, PARTICIPANTS: Population-based retrospective cohort analysis of linked data from the Queensland Pap Smear Register (PSR), the Queensland Hospital Admitted Patient Data Collection, and the Queensland Cancer Registry. 34 980 women aged 20-68 years (including 1592 Indigenous women) with their first HGA Pap smear result recorded on the PSR (index smear) during 2000-2009 were included and followed to the end of 2010. MAIN OUTCOME MEASURES: Time from the index smear to clinical investigation (histology test or cancer diagnosis date), censored at 12 months. RESULTS: The proportion of women who had a clinical investigation within 2 months of a HGA finding was lower for Indigenous (34.1%; 95% CI, 31.8-36.4%) than for non-Indigenous women (46.5%; 95% CI, 46.0-47.0%; unadjusted incidence rate ratio [IRR], 0.65; 95% CI, 0.60-0.71). This difference remained after adjusting for place of residence, area-level disadvantage, and age group (adjusted IRR, 0.74; 95% CI, 0.68-0.81). However, Indigenous women who had not been followed up within 2 months were subsequently more likely to have a clinical investigation than non-Indigenous women (adjusted IRR for 2-4 month interval, 1.21; 95% CI, 1.08-1.36); by 6 months, a similar proportion of Indigenous (62.2%; 95% CI, 59.8-64.6%) and non-Indigenous women (62.8%; 95% CI, 62.2-63.3%) had been followed up. CONCLUSIONS: Prompt follow-up after a HGA Pap smear finding needs to improve for Indigenous women. Nevertheless, slow follow-up is a smaller contributor to their higher cervical cancer incidence and mortality than their lower participation in cervical screening.

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

BACKGROUND: 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. METHODS: This was a retrospective, population-based study of 1,334,795 female Queensland residents, aged 20 to 69 years, who participated in cervical screening from 2000 to 2011; 26,829 were identified as Indigenous through linkage to hospitalization records. Participation rates were calculated as the number of women screened divided by the average estimated resident population, with adjustments made for hysterectomies, for each 2-, 3-, and 5-year screening period. Multivariate logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs), which were adjusted for age group, place of residence, and socioeconomic disadvantage. RESULTS: In 2010-2011, the 2-year participation rate was 55.7% (95% CI, 55.6%-55.9%) for non-Indigenous women and 33.5% (95% CI, 32.9%-34.1%) for Indigenous women; this represented a decrease from 2000-2001 (57.7% [95% CI, 57.6%-57.9%] and 35.3% [95% CI, 34.5%-36.1%], respectively). The difference between Indigenous and non-Indigenous women was greatest for those aged 45 to 49 years. The 3- and 5-year participation rates were higher within both groups, and the absolute differences between the 2 groups were larger. Significant interactions between the Indigenous status and the place of residence and socioeconomic disadvantage highlight that the Indigenous/non-Indigenous differential was evident in all places of residence except for very remote areas (OR, 0.99; 95% CI, 0.95-1.02) and was greatest in the most affluent areas (OR, 0.26; 95% CI, 0.24-0.27). CONCLUSIONS: Indigenous Australian women participate less than non-Indigenous women, and this gap has not closed. These results provide important benchmarks for the new Australian cervical screening program commencing in 2017, which will provide opportunities to reduce inequities for Indigenous women and address longstanding data deficiencies in the collection of the Indigenous status. Cancer 2016;122:1560-9. © 2016 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

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.

Factors associated with cancer-specific and overall survival among Indigenous and non-Indigenous gynecologic cancer patients in Queensland, Australia: a matched cohort study.

OBJECTIVE: Aboriginal and Torres Strait Islander women have a higher mortality rate due to gynecologic cancer compared with non-Indigenous women. For cervical cancer, Australian Indigenous women are less likely to survive 5 years following diagnoses than non-Indigenous women. This study investigates the factors associated with gynecologic cancer treatment and survival among Queensland indigenous and non-Indigenous women. METHODS: Australian Indigenous women diagnosed with uterine, cervical, ovarian, or other gynecologic cancers during 1998-2004 in the public hospital system were included. They were frequency matched on age (±5 years), residential remoteness, and cancer type to a random sample of non-Indigenous women. One- and 5-year cancer-specific survival was examined according to Indigenous status using Cox proportional hazards regression. RESULTS: Indigenous women (n = 137) compared with non-Indigenous women (n = 120) were less likely to be diagnosed with localized disease (49% vs 65%, P = 0.02) and had more comorbidities (52% vs 21%, P < 0.001). Indigenous women were less likely to receive any cancer treatment compared with non-Indigenous women (91% vs 98%, P = 0.01), although when excluding those with metastatic cancer, there was no significant difference in uptake of treatment (95% vs 91%, respectively, P = 0.31). Among those who did undergo treatment, there was no difference in time to treatment (median difference 0.5 days, P = 0.98). Gynecologic cancer-specific survival differences between Indigenous and non-Indigenous women were most prominent in the first year following diagnosis (hazard ratio [HR], 1.89; 95% confidence interval [CI], 1.06-3.38) and were no longer significant 5 years after diagnosis (HR, 1.47 [95% CI, 0.97-2.25]). For cervical cancer, crude 1-year survival was poorer for Indigenous women compared with non-Indigenous women (HR, 2.46 [95% CI, 1.03-5.90]), but was no different when adjusted for stage and treatment of cancer (HR, 1.00 [95% CI, 0.45-2.24]). CONCLUSIONS: Improving the early diagnosis of cervical cancer in Indigenous women may increase cancer-specific survival in the year following diagnosis.

Cancer outcomes for Aboriginal and Torres Strait Islander Australians in rural and remote areas.

OBJECTIVE: To examine the association between residential remoteness and stage of cancer at diagnosis, treatment uptake, and survival within the Australian Indigenous population. DESIGN: Systematic review and matched retrospective cohort study. SETTING: Australia. PARTICIPANTS: Systematic review: published papers that included a comparison of cancer stage at diagnosis, treatment uptake, mortality and/or survival for Indigenous people across remoteness categories were identified (n = 181). Fifteen papers (13 studies) were included in the review. Original analyses: new analyses were conducted using data from the Queensland Indigenous Cancer Study (QICS) comparing cancer stage at diagnosis, treatment uptake, and survival for Indigenous cancer patients living in rural/remote areas (n = 627, 66%) and urban areas (n = 329, 34%). MAIN OUTCOME MEASURES: Systematic review: Papers were included if there were related to stage of disease at diagnosis, treatment, mortality and survival of cancer. Restrictions were not placed on the outcome measures reported (e.g. standardised mortality ratios versus crude mortality rates). Original analyses: Odds ratios (OR, 95%CI) were used to compare stage of disease and treatment uptake between the two remoteness groups. Treatment uptake (treated/not treated) was analysed using logistic regression analysis. Survival was analysed using Cox proportional hazards regression. The final multivariate models included stage of cancer at diagnosis and area-level socioeconomic status (SEIFA). RESULTS: Existing evidence of variation in cancer outcomes for Indigenous people in remote compared with metropolitan areas is limited. While no previous studies have reported on differences in cancer stage and treatment uptake by remoteness within the Indigenous population, the available evidence suggests Indigenous cancer patients are less likely to survive their cancer the further they live from urban centres. New analysis of QICS data indicates that Indigenous cancer patients in rural/remote Queensland were less likely to be diagnosed with localised disease and less likely to receive treatment for their cancer compared to their urban counterparts. CONCLUSION: More research is needed to fully understand geographic differentials in cancer outcomes within the Indigenous population. Knowing how geographical location interacts with Indigenous status can help to identify ways of improving cancer outcomes for Indigenous Australians.

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.

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.

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

BACKGROUND: Indigenous 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. METHODS: A 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. RESULTS: Overall 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). CONCLUSION: In 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.

Under-screened Aboriginal and Torres Strait Islander women's perspectives on cervical screening.

Aboriginal and Torres Strait Islander women have lower participation in Australia's National Cervical Screening Program than other Australian women. Under-screened (including never screened) women's voices are rarely heard in research evidence, despite being a priority group for interventions to increase cervical screening participation. This study aimed to describe under-screened Aboriginal and Torres Strait Islander women's perspectives on cervical screening. Participants were 29 under-screened (women who had either never screened, had not screened in the previous five years or had recently screened in the past three months after more than five years) Aboriginal and Torres Strait Islander women from five communities across three states/territories. Female Aboriginal and Torres Strait Islander researchers Yarned with women about why they did not participate in screening and how to improve screening. Yarning is an Indigenous qualitative research method in which relationships and trust facilitate culturally safe conversation. Transcripts were analysed thematically. The proportion of eligible women who screened within 30 days after the Yarn was calculated. We identified four themes describing how the harms outweighed the benefits of cervical screening for under-screened women. These were: 1) distress, discomfort, and trauma; 2) lack of privacy and control; 3) complicated relationships with health care providers (HCPs); and 4) pressured, insensitive, and/or culturally unsafe communication from HCPs. Under-screened women who had recently screened had maintained privacy and control through self-collection and had experienced trauma-informed and empathetic care from their HCPs. While we cannot unequivocally attribute women's subsequent participation in screening to their involvement in this study, it is notable that one third of eligible under-screened women were screened within 30 days after the Yarn. Enhancing privacy, implementing trauma-informed approaches to care and sensitivity to the clinician-client relationship dynamics could enhance women's sense of comfort in, and control over, the screening procedure. The opportunity to Yarn about cervical screening and self-collection may address these issues and support progress toward cervical cancer elimination in Australia.

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.

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

BACKGROUND: Overall, 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. METHODS: Rates 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 Pearson's Chi-squared analysis to compare categorical data (proportions) and Cox proportional hazard models to assess survival differences. RESULTS: There 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). CONCLUSION: These 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.

Health care provider perspectives on cervical screening for Aboriginal and Torres Strait Islander women: a qualitative study.

OBJECTIVE: To investigate perspectives of primary health care providers (HCPs) on providing cervical screening for Aboriginal and Torres Strait Islander women, who experience a higher burden of cervical cancer than other Australian women. METHODS: Semi-structured interviews with 13 HCPs from four Australian Indigenous primary health care centres (PHCCs). Transcripts were thematically analysed. RESULTS: HCPs discussed the need to approach cervical screening with sensitivity to women's emotional and cultural needs and sustaining relationships built on trust and respect. HCPs reported challenges in promoting screening to Aboriginal and Torres Strait Islander women due to cumbersome systems, competing clinical priorities, workforce capacity limitations and specific challenges associated with implementing the renewed National Cervical Screening Program. CONCLUSIONS: In practice, HCPs experience several challenges to delivering cervical screening. Understanding HCPs' perspectives on their approach to cervical screening delivery, and the systems in which this occurs, can help to ensure that they receive adequate support and resources to deliver cervical screening to Aboriginal and Torres Strait Islander women. Implications for public health: It is important that HCPs adopt a multi-faceted, person-centred approach to cervical screening that is responsive to women's needs and that works synchronously with supportive PHCC services and systems and the National Cancer Screening Register.

Investigating inequities in cardiovascular care and outcomes for Queensland Aboriginal and Torres Strait Islander people: protocol for a hospital-based retrospective cohort data linkage project.

INTRODUCTION: Cardiovascular disease (CVD) represents a significant burden of disease for Aboriginal and Torres Strait Islander people, a population that continues to experience a lower life expectancy than other Australians. The aim of the Better Cardiac Care Data Linkage project is to describe patient care pathways and to identify disparities in care and health outcomes between Aboriginal and Torres Strait Islander people and other Queensland residents diagnosed with CVD in the state of Queensland. METHODS: This is a population-based retrospective cohort study using linked regional, state and national health and administrative data collections to describe disparities in CVD healthcare in primary and secondary prevention settings and during hospitalisation. The CVD cohort will be identified from the Queensland Hospital Admitted Patient Data Collection for admissions that occurred between 1 July 2010 and 31 June 2016 and will include relevant International Classification of Disease codes for ischaemic heart disease, congestive heart failure, stroke, acute rheumatic fever and rheumatic heart disease. Person-level data will be linked by Data Linkage Queensland and the Australian Institute of Health and Welfare (AIHW) in accordance with ethical and public health approvals to describe the patient journey prior to, during and post the hospital admission. ANALYSIS: This project will focus largely on descriptive epidemiological measures and multivariate analysis of clinical care standards and outcomes for Aboriginal and Torres Strait Islander people compared with other Queenslanders, including identification of risk factors for suboptimal care and change over time. Variation in care pathways and patient outcomes will be compared by Indigenous status, sex, age group, remoteness of residence, year of index hospitalisation and socioeconomic status. Cox models for time-to-event data and mixed models or generalised estimating equations for longitudinal data will be used to measure change over time where temporal effects exist. ETHICS AND DISSEMINATION: Ethical approval has been granted by Human Research Ethics Committees of the Prince Charles Hospital (HREC/15/QPCH/289) and the AIHW (EO2016-1-233). The Northern Territory Department of Health and Menzies School of Health Research have also provided reciprocal ethical approval of the project (HREC 2019-3490). The deidentified results will be summarised in a report and shared with investigators, advisory groups, Queensland Health and key stakeholders. Findings will be disseminated through workshops, conferences and will be published in peer-reviewed journals.

Indigenous Australian women's experiences of participation in cervical screening.

Aboriginal and Torres Strait Islander (collectively, Indigenous Australian) women experience a higher burden of cervical cancer than other women. The National Cervical Screening Program (NCSP) is failing to meet the needs of Indigenous Australian women, resulting in many women not regularly participating in cervical screening. However, one third of Indigenous Australian women do participate in cervical screening. The reasons that some women in this population commence and continue to screen remain unheard but could provide insights to support women who currently do not participate. We aimed to describe Indigenous Australian women's experiences and views of participation in cervical screening by yarning (a culturally-appropriate interview technique) with 50 Indigenous Australian women aged 25-70 years who had completed cervical screening in the past five years, recruited via Primary Health Care Centres (PHCCs) from three jurisdictions. Aboriginal or Torres Strait Islander women researchers conducted the interviews. Thematic analysis identified six themes: screening as a means of staying strong and in control; overcoming fears, shame, and negative experiences of screening; needing to talk openly about screening; the value of trusting relationships with screening providers; logistical barriers; and overcoming privacy concerns for women employed at PHCCs. Despite describing screening as shameful, invasive, and uncomfortable, women perceived it as a way of staying healthy and exerting control over their health. This ultimately supported their participation and a sense of empowerment. Women valued open discussion about screening and strong relationships with health providers. We identified logistical barriers and specific barriers faced by women employed at PHCCs. This study is strengthened by a research approach that centred Indigenous Australian women's voices. Understanding the experiences of Indigenous Australian women who participate in screening will help screening providers support women to start and continue to screen regularly. Recommendations for practice are provided.

Aboriginal women have a higher risk of cervical abnormalities at screening; South Australia, 1993-2016.

OBJECTIVE: Cervical cancer mortality has halved in Australia since the national cervical screening program began in 1991, but elevated mortality rates persist for Aboriginal and Torres Strait Islander women (referred to as Aboriginal women in this report). We investigated differences by Aboriginal status in abnormality rates predicted by cervical cytology and confirmed by histological diagnoses among screened women. METHODS: Using record linkage between cervical screening registry and public hospital records in South Australia, we obtained Aboriginal status of women aged 20-69 for 1993-2016 (this was not recorded by the registry). Differences in cytological abnormalities were investigated by Aboriginal status, using relative risk ratios from mixed effect multinomial logistic regression modelling. Odds ratios were calculated for histological high grade results for Aboriginal compared with non-Aboriginal women. RESULTS: Of 1,676,141 linkable cytology tests, 5.8% were abnormal. Abnormal results were more common for women who were younger, never married, and living in a major city or socioeconomically disadvantaged area. After adjusting for these factors and numbers of screening episodes, the relative risk of a low grade cytological abnormality compared with a normal test was 14% (95% confidence interval 5-24%) higher, and the relative risk of a high grade cytological abnormality was 61% (95% confidence interval 44-79%) higher, for Aboriginal women. The adjusted odds ratio of a histological high grade was 76% (95% confidence interval 46-113%) higher. CONCLUSIONS: Ensuring that screen-detected abnormalities are followed up in a timely way by culturally acceptable services is important for reducing differences in cervical cancer rates between Aboriginal and non-Aboriginal women.

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.

Comorbidity and cervical cancer survival of Indigenous and non-Indigenous Australian women: A semi-national registry-based cohort study (2003-2012).

BACKGROUND: Little is known about the impact of comorbidity on cervical cancer survival in Australian women, including whether Indigenous women's higher prevalence of comorbidity contributes to their lower survival compared to non-Indigenous women. METHODS: Data for cervical cancers diagnosed in 2003-2012 were extracted from six Australian state-based cancer registries and linked to hospital inpatient records to identify comorbidity diagnoses. Five-year cause-specific and all-cause survival probabilities were estimated using the Kaplan-Meier method. Flexible parametric models were used to estimate excess cause-specific mortality by Charlson comorbidity index score (0,1,2+), for Indigenous women compared to non-Indigenous women. RESULTS: Of 4,467 women, Indigenous women (4.4%) compared to non-Indigenous women had more comorbidity at diagnosis (score ≥1: 24.2% vs. 10.0%) and lower five-year cause-specific survival (60.2% vs. 76.6%). Comorbidity was associated with increased cervical cancer mortality for non-Indigenous women, but there was no evidence of such a relationship for Indigenous women. There was an 18% reduction in the Indigenous: non-Indigenous hazard ratio (excess mortality) when comorbidity was included in the model, yet this reduction was not statistically significant. The excess mortality for Indigenous women was only evident among those without comorbidity (Indigenous: non-Indigenous HR 2.5, 95%CI 1.9-3.4), indicating that factors other than those measured in this study are contributing to the differential. In a subgroup of New South Wales women, comorbidity was associated with advanced-stage cancer, which in turn was associated with elevated cervical cancer mortality. CONCLUSIONS: Survival was lowest for women with comorbidity. However, there wasn't a clear comorbidity-survival gradient for Indigenous women. Further investigation of potential drivers of the cervical cancer survival differentials is warranted. IMPACT: The results highlight the need for cancer care guidelines and multidisciplinary care that can meet the needs of complex patients. Also, primary and acute care services may need to pay more attention to Indigenous Australian women who may not obviously need it (i.e. those without comorbidity).

Association between comorbidity and participation in breast and cervical cancer screening: A systematic review and meta-analysis.

BACKGROUND: Comorbidity is associated with poor outcomes for cancer patients but it is less clear how it influences cancer prevention and early detection. This review synthesizes evidence from studies that have quantified the association between comorbidity and participation in breast and cervical screening. METHODS: PubMed, CINAHL and EMBASE databases were systematically searched using key terms related to cancer screening and comorbidity for original research articles published between 1 January 1991 and 21 March 2016. Two reviewers independently screened 1283 studies that met eligibility criteria related to Population (adult, non-cancer populations), Exposure (comorbidity), Comparison (a 'no comorbidity' group), and Outcome (participation in breast cancer or cervical screening). Data was extracted and risk of bias assessed using a standardised tool from the 22 studies identified for inclusion (17 breast; 13 cervical). Meta-analyses were performed for participation in breast and cervical screening, stratified by important study characteristics. RESULTS: The majority of studies were conducted in the United States. Results of individual studies were variable. Most had medium to high risk of bias. Based on the three "low risk of bias" studies, mammography screening was less common among those with comorbidity (pooled Odds Ratio 0.66, 95%CI 0.44-0.88). The one "low risk of bias" study of cervical screening reported a negative association between comorbidity and participation. CONCLUSION: While a definitive conclusion could not be drawn, the results from high quality studies suggest that women with comorbidity are less likely to participate in breast, and possibly cervical, cancer screening.

Indigenous Australians with non-small cell lung cancer or cervical cancer receive suboptimal treatment.

BACKGROUND: Lung cancer and cervical cancer are higher in incidence for Indigenous Australians and survival is worse compared with non-Indigenous Australians. Here we aim to determine if being Indigenous and/or other factors are associated with patients receiving "suboptimal treatment" compared to "optimal treatment" according to clinical guidelines for two cancer types. METHODS: Data were collected from hospital medical records for Indigenous adults diagnosed with cervical cancer and non-small cell lung cancer (NSCLC) and a frequency-matched comparison group of non-Indigenous patients in the Queensland Cancer Registry between January 1998 and December 2004. The two cancer types were analyzed separately. RESULTS: A total of 105 women with cervical cancer were included in the study, 56 of whom were Indigenous. Indigenous women had higher odds of not receiving optimal treatment according to clinical guidelines (unadjusted OR 7.1; 95% CI, 1.5-33.3), even after adjusting for stage (OR 5.7; 95% CI, 1.2-27.3). Of 225 patients with NSCLC, 198 patients (56% Indigenous) had sufficient information available to be analyzed. The odds of receiving suboptimal treatment were significantly higher for Indigenous compared to non-Indigenous NSCLC patients (unadjusted OR 1.9; 95% CI, 1.0-3.6) and remained significant after adjusting for stage, comorbidity and age (adjusted OR 2.1; 95% CI, 1.1-4.1). CONCLUSIONS: The monitoring of treatment patterns and appraisal against guidelines can provide valuable evidence of inequity in cancer treatment. We found that Indigenous people with lung cancer or cervical cancer received suboptimal treatment, reinforcing the need for urgent action to reduce the impact of these two cancer types on Indigenous people.

Breast cancer diagnosis, patterns of care and burden of disease in Queensland, Australia (1998-2004): does being Indigenous make a difference?

OBJECTIVES: We compared patterns of care, comorbidity, disability-adjusted life-years (DALYs) and survival in Indigenous and non-Indigenous women with breast cancer in Queensland, Australia (1998-2004). METHODS: A cohort study of Indigenous (n = 110) and non-Indigenous women (n = 105), frequency matched on age and remoteness. We used Pearson's Chi-squared analysis to compare proportions, hazard models to assess survival differences and calculated disability-adjusted life years (DALYs). RESULTS: Indigenous women were more likely to be socially disadvantaged (43 vs. 20 %, p < 0.01) have comorbidity (42 vs. 18 % p < 0.01), and have regional spread or distant metastasis (metastasis, 51 vs. 36 %, p = 0.02) than non-Indigenous women; there was no difference in treatment patterns. More Indigenous women died in the follow-up period (p = 0.01). DALY's were 469 and 665 per 100,000 for Indigenous and non-Indigenous women, respectively, with a larger proportion of the burden attributed to premature death among the former (63 vs. 59 %). CONCLUSIONS: Indigenous women with breast cancer received comparable treatment to their non-Indigenous counterparts. The higher proportion of DALYs related to early death in Indigenous women suggests higher fatality with breast cancer in this group. Later stage at diagnosis and higher comorbidity presence among Indigenous women reinforce the need for early detection and improved management of co-existing disease.