Association of diabetes with survival among cohorts of Indigenous and non-Indigenous Australians with cancer

Utilising the CREATE quality appraisal tool to analyse Aboriginal and Torres Strait Islander peoples' involvement and reporting of cancer research in Australia

OBJECTIVE

We aimed to evaluate Aboriginal and Torres Strait Islander involvement in research focusing on cancer experiences using an Aboriginal and Torres Strait Islander quality appraisal tool (the QAT).

METHODS

We conducted a systematic review of the peer-reviewed literature on Aboriginal and Torres Strait Islander peoples' experiences associated with cancer, recently published elsewhere. We then appraised articles for the inclusion of Aboriginal and Torres Strait Islander-led research, community consultation, and involvement.

RESULTS

91 articles were appraised. A lack of Aboriginal and Torres Strait Islander-led research and consultation was reported in the majority of articles, only 10 (11%) demonstrated success across seven (50%) or more questions of the QAT.

CONCLUSIONS

This review underscores the need for anti-racist research and publication practices that actively engage Aboriginal and Torres Strait Islander peoples and researchers. This approach is vital to enhance cancer outcomes within these communities.

IMPLICATIONS FOR PUBLIC HEALTH

To advance and prioritise appropriate involvement of Aboriginal and Torres Strait Islander peoples in cancer research, the onus must be on 'systems owners,' including academic journals and institutions, to require and report genuine engagement as standard practice. Researchers will produce higher-calibre research with a strengths-based focus, advancing the cause of equitable research.

Systematic review of Aboriginal and Torres Strait Islander peoples' experiences and supportive care needs associated with cancer

BACKGROUND

Persistent disparities exist between Aboriginal and Torres Strait Islander peoples (the Indigenous peoples of Australia) and non-Indigenous Australians associated with cancer, with Aboriginal and Torres Strait Islander peoples experiencing a longer time to treatment, higher morbidity rates, and higher mortality rates. This systematic review aimed to investigate findings and recommendations in the literature about the experiences and supportive care needs of Aboriginal and Torres Strait Islander peoples with cancer in Australia.

METHODS

A qualitative systematic review was conducted using thematic analysis. Database searches were conducted in CINAHL, Informit, MEDLINE, ProQuest, Scopus, and Web of Science for articles published between January 2000 and December 2021. There were 91 included studies which were appraised using the Mixed Methods Appraisal Tool. The included studies reported on the experiences of cancer and supportive care needs in Aboriginal and Torres Strait Islander populations.

RESULTS

Six key themes were determined: Culture, family, and community; cancer outcomes; psychological distress; access to health care; cancer education and awareness; and lack of appropriate data. Culture was seen as a potential facilitator to achieving optimal cancer care, with included studies highlighting the need for culturally safe cancer services and the routine collection of Aboriginal and Torres Strait Islander status in healthcare settings.

CONCLUSION

Future work should capitalize on these findings by encouraging the integration of culture in healthcare settings to increase treatment completion and provide a positive experience for Aboriginal and Torres Strait Islander peoples with cancer.

Equity of Cancer and Diabetes Co-Occurrence: A National Study With 44 Million Person-Years of Follow-Up

PURPOSE

The co-occurrence of diabetes and cancer is becoming increasingly common, and this is likely to compound existing inequities in outcomes from both conditions within populations.

METHODS

In this study, we investigate the co-occurrence of cancer and diabetes by ethnic groups in New Zealand. National-level diabetes and cancer data on nearly five million individuals over 44 million person-years were used to describe the rate of cancer in a national prevalent cohort of peoples with diabetes versus those without diabetes, by ethnic group (Māori, Pacific, South Asian, Other Asian, and European peoples).

RESULTS

The rate of cancer was greater for those with diabetes regardless of ethnic group (age-adjusted rate ratios, Māori, 1.37; 95% CI, 1.33 to 1.42; Pacific, 1.35; 95% CI, 1.28 to 1.43; South Asian, 1.23; 95% CI, 1.12 to 1.36; Other Asian, 1.31; 95% CI, 1.21 to 1.43; European, 1.29; 95% CI, 1.27 to 1.31). Māori had the highest rate of diabetes and cancer co-occurrence. Rates of GI, endocrine, and obesity-related cancers comprised a bulk of the excess cancers occurring among Māori and Pacific peoples with diabetes.

CONCLUSION

Our observations reinforce the need for the primordial prevention of risk factors that are shared between diabetes and cancer. Also, the commonality of diabetes and cancer co-occurrence, particularly for Māori, reinforces the need for a multidisciplinary, joined-up approach to the detection and care of both conditions. Given the disproportionate burden of diabetes and those cancers that share risk factors with diabetes, action in these areas is likely to reduce ethnic inequities in outcomes from both conditions.

Influence of Preexisting Diabetes on Survival After a Breast Cancer Diagnosis in First Nations Women in Ontario, Canada

PURPOSE

Survival after a breast cancer diagnosis is poorer in First Nations women with a preexisting comorbidity compared with comorbidity-free First Nations women in Ontario, Canada. Given the high prevalence of diabetes in this population, it is important to determine whether preexisting diabetes is related to poorer survival after a breast cancer diagnosis.

METHODS

All First Nations women were identified from a cohort of First Nations people diagnosed with breast cancer in diagnostic periods-1995 to 1999 and 2000 to 2004-and seen at a regional cancer program (RCP) in Ontario. Preexisting diabetes status and other factors, such as age at diagnosis, body mass index, and stage at diagnosis, were collected from medical charts at the regional cancer programs. The association between preexisting diabetes and First Nations status was examined by each of the demographic, personal, tumor, and treatment factors using logistic regression models. Survival was compared between First Nations women with (n = 67) and without (n = 215) preexisting diabetes, adjusted by significant study factors using a Cox proportional hazards regression model.

RESULTS

The 5-year survival rate among First Nations women with diabetes was 59.8% versus 78.7% among those without diabetes (P < .01). Preexisting diabetes significantly increased the risk of death among First Nations women with breast cancer (hazard ratio, 1.87; 95% CI, 1.12 to 3.13) after adjustment for age group, period of diagnosis, body mass index, other comorbidities at diagnosis, and stage.

CONCLUSION

This study recommends awareness of this survival discrepancy among the treatment team for First Nations patients with breast cancer with preexisting diabetes.

The impact of comorbidity on cancer and its treatment

Answer questions and earn CME/CNE Comorbidity is common among cancer patients and, with an aging population, is becoming more so. Comorbidity potentially affects the development, stage at diagnosis, treatment, and outcomes of people with cancer. Despite the intimate relationship between comorbidity and cancer, there is limited consensus on how to record, interpret, or manage comorbidity in the context of cancer, with the result that patients who have comorbidity are less likely to receive treatment with curative intent. Evidence in this area is lacking because of the frequent exclusion of patients with comorbidity from randomized controlled trials. There is evidence that some patients with comorbidity have potentially curative treatment unnecessarily modified, compromising optimal care. Patients with comorbidity have poorer survival, poorer quality of life, and higher health care costs. Strategies to address these issues include improving the evidence base for patients with comorbidity, further development of clinical tools to assist decision making, improved integration and coordination of care, and skill development for clinicians. CA Cancer J Clin 2016;66:337-350. © 2016 American Cancer Society.

Colorectal cancer among Indigenous and non-Indigenous people in Queensland, Australia: Toward survival equality

AIM

While Indigenous people in Queensland have lower colorectal cancer (CRC) incidence and mortality than the rest of the population, CRC remains the third most frequent cancer among Australian Indigenous people overall. This study aimed to investigate patterns of care and survival between Indigenous and non-Indigenous Australians with CRC.

METHODS

Through a matched-cohort design we compared 80 Indigenous and 85 non-Indigenous people all diagnosed with CRC and treated in Queensland public hospitals during 1998-2004 (frequency matched on age, sex, geographical remoteness). We compared clinical and treatment data (Pearson's chi-square) and all-cause and cancer survival (Cox regression analysis).

RESULTS

Indigenous patients with CRC were not significantly more likely to have comorbidity, advanced disease at diagnosis or less treatment than non-Indigenous people. There was also no statistically significant difference in all-cause survival (HR 1.14, 95% CI 0.69, 1.89) or cancer survival (HR 1.01, 95% CI 0.60, 1.69) between the two groups.

CONCLUSIONS

Similar CRC mortality among Indigenous and other Australians may reflect both the lower incidence and adequate management. Increasing life expectancy and exposures to risk factors suggests that Indigenous people are vulnerable to a growing burden of CRC. Primary prevention and early detection will be of paramount importance to future CRC control among Indigenous Australians. Current CRC management must be maintained and include prevention measures to ensure that predicted increases in CRC burden are minimized.

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.

Association of diabetes mellitus and pancreatic adenocarcinoma: a meta-analysis of 88 studies

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is often diagnosed at an advanced, incurable stage. Previous epidemiological data suggests that diabetes mellitus (DM) is a risk factor for PDAC, which may be important in early detection. However, the strength of this association needs to be determined, taking into account a number of recently published studies.

METHODS

A systematic review of the association between DM and PDAC was undertaken by searching electronic databases and journal references from 1973 to 2013. Summary estimates were obtained separately for case-control and cohort studies by means of a 'random effects' approach. Data pertaining to the DM was recorded and plotted at both an individual and study level, with the relative risks (RR) pooled separately to determine the relationship of DM duration and PDAC.

RESULTS

A total of 88 independent studies, including 50 cohort and 39 case-control studies were examined. The overall summary-combined RR was 1.97 (95 % CI 1.78-2.18) with marked heterogeneity that could not be clearly attributed to any subgroup analyses. The risk of PDAC was greatest early after the diagnosis of DM but remained elevated long after the diagnosis. The individual-level RR ranged from 6.69 at less than 1 year to 1.36 at 10 years.

CONCLUSION

The results demonstrate a strong association between PDAC and recently diagnosed DM, which may be attributed to a paraneoplastic effect. However, the presence of diabetes also remains a modest risk factor for the development of PDAC long-term. Selective screening of patients with new-onset DM for PDAC needs to be considered.

Diabetes and cancer I: risk, survival, and implications for screening

Type 2 diabetes mellitus (DM) and cancer are common diseases that are frequently diagnosed in the same individual. An association between the two conditions has long been postulated. Here, we review the epidemiological evidence for increased risk of cancer, decreased cancer survival, and decreased rates of cancer screening in diabetic patients. The risk for several cancers, including cancers of the pancreas, liver, colorectum, breast, urinary tract, and endometrium, is increased in patients with DM. In a pooled risk analysis weighting published meta-analytic relative risk (RR) for individual cancer by differences in their incidence rates, we found a population RR of 0.97 (95 % CI, 0.75-1.25) in men and 1.29 (95 % CI, 1.16-1.44) in women. All meta-analyses showed an increased relative risk for cancer in diabetic men, except studies of prostate cancer, in which a protective effect was observed. The relationship between diabetes and cancer appears to be complex, and at present, a clear temporal relationship between the two conditions cannot be defined. DM also impacts negatively on cancer-related survival outcomes and cancer screening rates. The overwhelming evidence for lower cancer screening rates, increased incidence of certain cancers, and poorer prognosis after cancer diagnosis in diabetic patients dictates a need for improved cancer care in diabetic individuals through improved screening measures, development of risk assessment tools, and consideration of cancer prevention strategies in diabetic patients. Part two of this review focuses on the biological and pharmacological mechanisms that may account for the association between DM and cancer.

Prognostic role of diabetes mellitus in hepatocellular carcinoma patients after curative treatments: a meta-analysis

BACKGROUND

The prognostic role of diabetes mellitus (DM) coexisting with hepatocellular carcinoma (HCC) remains controversial. To clarify its impact on survival in HCC patients after curative treatments, a meta-analysis was performed.

DATA SOURCES

Eligible studies were identified through multiple search strategies in the databases PubMed (MEDLINE), EMBASE, the Cochrane Library and ACP Journal Club between January 1950 and March 2010. Ten studies fulfilled the inclusion criteria, and data were aggregated comparing overall survival and recurrence-free survival in HCC patients according to DM status.

RESULTS

The pooled hazard ratios (HRs) estimate for overall survival was 1.34 (95% CI, 1.18-1.51; P<0.0001) and for recurrence-free survival was 1.48 (95% CI, 1.00-2.18; P<0.0001), showing a worse survival for HCC with coexisting DM. However, the patients with DM had a shorter survival time in HCV-related HCC (HR=1.71; 95% CI, 1.10-2.66; P=0.016), while HBV-related cases were not significantly different (HR=1.29; 95% CI, 0.69-2.40; P=0.182). Meanwhile, the coexistence of DM impaired overall survival in HCC patients with a small tumor burden (HR=1.63; 95% CI, 1.25-2.12; P<0.0001).

CONCLUSION

HCC patients with coexisting DM have a shorter survival time and a higher risk for tumor recurrence after curative treatments, while the precise value should be defined in more clinical trials with consistent methodology, especially prospective studies.

Stage at diagnosis and comorbidity influence breast cancer survival in First Nations women in Ontario, Canada

BACKGROUND

Indigenous populations in Canada and abroad have poorer survival after a breast cancer diagnosis compared with their geographic counterparts; however, the influence of many demographic, personal, tumor, and treatment factors has not been examined to describe this disparity according to stage at diagnosis.

METHODS

A case-case design was employed to compare First Nations (FN) women (n = 287) to a frequency-matched random sample of non-FN women (n = 671) diagnosed with breast cancer within the Ontario Cancer Registry. Women were matched on period of diagnosis (1995-1999 and 2000-2004), age at diagnosis (<50 vs. ≥50), and Regional Cancer Centre (RCC). Stage and other factors were collected from medical charts at the RCCs. Survival was compared using an adjusted Cox proportional hazards model and stratified by stage at diagnosis (I, II, and III-IV). Determinants of survival in FN women stratified by stage at diagnosis were also modeled.

RESULTS

Survival was more than three times poorer for FN women diagnosed at stage I than for non-FN women (HR = 3.10, 95% CI = 1.39-6.88). The risk of death after a stage I breast cancer diagnosis was about five times higher among FN women with a comorbidity other than diabetes (HR = 4.65, 95% CI = 1.39-15.53) and was more than five times greater for women with diabetes (HR = 5.49, 95% CI = 1.69-17.90) than for those without a comorbidity.

CONCLUSIONS

Having a preexisting comorbidity was the most important factor in explaining the observed survival disparity among FN women.

IMPACT

Improving the general health status of FN women could increase their survival after an early-stage breast cancer diagnosis.

Australia's national bowel cancer screening program: does it work for indigenous Australians?

BACKGROUND

Despite a lower incidence of bowel cancer overall, Indigenous Australians are more likely to be diagnosed at an advanced stage when prognosis is poor. Bowel cancer screening is an effective means of reducing incidence and mortality from bowel cancer through early identification and prompt treatment. In 2006, Australia began rolling out a population-based National Bowel Cancer Screening Program (NBCSP) using the Faecal Occult Blood Test. Initial evaluation of the program revealed substantial disparities in bowel cancer screening uptake with Indigenous Australians significantly less likely to participate in screening than the non-Indigenous population.This paper critically reviews characteristics of the program which may contribute to the discrepancy in screening uptake, and includes an analysis of organisational, structural, and socio-cultural barriers that play a part in the poorer participation of Indigenous and other disadvantaged and minority groups.

METHODS

A search was undertaken of peer-reviewed journal articles, government reports, and other grey literature using electronic databases and citation snowballing. Articles were critically evaluated for relevance to themes that addressed the research questions.

RESULTS

The NBCSP is not reaching many Indigenous Australians in the target group, with factors contributing to sub-optimal participation including how participants are selected, the way the screening kit is distributed, the nature of the test and comprehensiveness of its contents, cultural perceptions of cancer and prevailing low levels of knowledge and awareness of bowel cancer and the importance of screening.

CONCLUSIONS

Our findings suggest that the population-based approach to implementing bowel cancer screening to the Australian population unintentionally excludes vulnerable minorities, particularly Indigenous and other culturally and linguistically diverse groups. This potentially contributes to exacerbating the already widening disparities in cancer outcomes that exist among Indigenous Australians. Modifications to the program are recommended to facilitate access and participation by Indigenous and other minority populations. Further research is also needed to understand the needs and social and cultural sensitivities of these groups around cancer screening and inform alternative approaches to bowel cancer screening.