15th December 2017, Volume 130 Number 1467

Charis Brown, Chunhuan Lao, Ross Lawrenson, Sandar Tin Tin, Michelle Schaaf, Jacquie Kidd, Anne Allan-Moetaua, Josephine Herman, Reena Raamsroop, Ian Campbell, Mark Elwood

Breast cancer is a significant health issue for women in New Zealand. There are approximately 3,000 registrations and around 600 deaths during 2012.1 One hundred and twenty Pasifika women were…

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Summary

Pasifika women were diagnosed with more advanced breast cancer and with a poorer prognosis. The presence of advanced cancer is associated with less breast screening, higher deprivation, age and some biological factors. For those of screening age, adherence to the screening programme and improvements in access to earlier diagnosis for Pasifika women under the current screening age have the potential to make a substantial difference in the number of Pasifika women presenting with late-stage disease.

Abstract

Aim

Breast cancer in New Zealand-based Pasifika women is a significant issue. Although Pasifika women have a lower incidence of breast cancer compared to New Zealand European women, they have higher breast cancer mortality and lower five-year survival. The aim of this study was to describe the characteristics and tumour biology of Pasifika women and to compare New Zealand European women to identify what factors impact on early (Stage 1 and 2) vs advanced stage (Stage 3 and 4) at diagnosis.

Method

Data on all Pasifika and New Zealand European women diagnosed with breast cancer (C50) during the period 1 June 2000 to 31 May 2013 was extracted from the Auckland and Waikato Breast Cancer Registries. Descriptive tables and Chi-square test were used to examine differences in characteristics and tumour biology between Pasifika and New Zealand European women. Logistic regression was used to identify factors that contributed to an increased risk of advanced stage at diagnosis.

Results

A significantly higher proportion of Pasifika women had advanced disease at diagnosis compared to New Zealand European women (33.3% and 18.3%, respectively). Cancer biology in Pasifika women was more likely to be: 1) HER2+, 2) ER/PR negative and 3) have a tumour size of ≥50mm. Pasifika women live in higher deprivation areas of 9–10 compared to New Zealand European women (55% vs 14%, respectively) and were less likely to have their cancer identified through screening. Logistic regression showed that if Pasifika women were on the screen-detected pathway they had similar odds (not sig.) of having advanced disease at diagnosis to New Zealand European women.

Conclusion

Mode of detection, deprivation, age and some biological factors contributed to the difference in odds ratio between Pasifika and New Zealand European women. For those of screening age, adherence to the screening programme and improvements in access to earlier diagnosis for Pasifika women under the current screening age have the potential to make a substantial difference in the number of Pasifika women presenting with late-stage disease.

Author Information

Charis Brown, Director, SMART Marketing and Research, University of Waikato, Hamilton;
Chunhuan Lao, Research Fellow, University of Waikato, Hamilton;
Ross Lawrenson, Professor of Population Health, University of Waikato, Hamilton;
Sandar Tin Tin, Senior Research Fellow, Section of Epidemiology and Biostatistics, University of Auckland, Auckland; Michelle Schaaf, Lecturer, University of Otago, Dunedin;
Jacquie Kidd, Senior Lecturer, University of Auckland, Auckland;
Anne Allan-Moetaua, Manager, Central Pasifika Collective, Wellington;
Josephine Herman, Research Fellow, Section of Epidemiology and Biostatistics, University of Auckland, Auckland; Reena Raamsroop, Surgical Pathology Department, Waitemata District Health Board, Auckland; Ian Campbell, Breast and General Surgeon, Waikato District Health Board, Hamilton;
Mark Elwood, Professor of Cancer Epidemiology, Section of Epidemiology and Biostatistics, University of Auckland, Auckland. 

Acknowledgements

Funding from Health Research Council/Ministry of Health, reference number: 14/484: Improving outcomes for women with breast cancer in New Zealand.

Correspondence

Dr Chunhuan Lao, Research Fellow, The University of Waikato, Private Bag 3105, Hamilton 3240.

Correspondence Email

clao@waikato.ac.nz

Competing Interests

Dr Brown, Dr Tin Tin and Dr Campbell report grants from Health Research Council of New Zealand during the conduct of the study.

References

  1. Ministry of Health. Cancer: New registrations and deaths 2012. Ministry of Health: Wellington, New Zealand; 2015.
  2. Bramley D, Hebert P, Jackson R, Chassin M. Indigenous disparities in disease-specific mortality, a cross-country comparison: New Zealand, Australia, Canada, and the United States. N Z Med J. 2004; 117(1207):U1215.
  3. Dachs GU, Currie MJ, McKenzie F, et al. Cancer disparities in indigenous Polynesian populations: Māori, Native Hawaiians, and Pacific people. The Lancet Oncology. 2008; 9(5):473–484.
  4. Valery PC, Coory M, Stirling J, Green AC. Cancer diagnosis, treatment, and survival in Indigenous and non-Indigenous Australians: a matched cohort study. Lancet. 2006; 367(9525):1842–1848.
  5. Althuis MD, Dozier JM, Anderson WF, et al. Global trends in breast cancer incidence and mortality 1973–1997. Int J Epidemiol. 2005; 34(2):405–412.
  6. Hill S, Sarfati D, Blakely T, et al. Survival disparities in Indigenous and non-Indigenous New Zealanders with colon cancer: the role of patient comorbidity, treatment and health service factors. J Epidemiol Comm Health. 2010; 64:117–123.
  7. Hill S, Sarfati D, Blakely T, et al. Ethnicity and management of colon cancer in New Zealand: do indigenous patients get a worse deal? Cancer. 2010; 116(13):3205–3214.
  8. Hill S, Sarfati D, Robson B, Blakely T. Indigenous inequalities in cancer: what role for health care? ANZ J Surg. 2013; 83(1–2):36–41.
  9. Cunningham R, Shaw C, Blakely T, et al. Ethnic and socioeconomic trends in breast cancer incidence in New Zealand. BMC Cancer. 2010; 10:674.
  10. Jeffreys M, Sarfati D, Stevanovic V, et al. Socioeconomic inequalities in cancer survival in New Zealand: the role of extent of disease at diagnosis. Cancer Epidemiol Biomarkers Prev. 2009; 18(3):915–921.
  11. Sarfati D, Blakely T, Pearce N. Measuring cancer survival in populations: relative survival vs cancer-specific survival. Int J Epidemiol. 2010; 39:598–610.
  12. Sarfati D, Blakely T, Shaw C, et al. Patterns of disparity: ethnic and socio-economic trends in breast cancer mortality in New Zealand. Cancer Causes Control. 2006; 17(5):671–678.
  13. Soeberg M, Blakely T, Sarfati D, et al. Cancer Trends: Trends in cancer survival by ethnic and socioeconomic group, New Zealand 1991–2004. University of Otago and Ministry of Health: Wellington, New Zealand; 2012.
  14. Seneviratne S, Campbell I, Scott N, et al. Impact of mammographic screening on ethnic and socioeconomic inequities in breast cancer stage at diagnosis and survival in New Zealand: a cohort study. BMC Public Health. 2015; 15:46.
  15. Seneviratne S, Campbell I, Scott N, et al. Ethnic differences in breast cancer survival in New Zealand: contributions of differences in screening, treatment, tumour biology, demographics and comorbidities. Cancer Causes Control. 2015; 26(12):1813–1824.
  16. Obertova Z, Scott N, Brown C, et al. Survival disparities between Maori and non-Maori men with prostate cancer in New Zealand. BJU Int. 2015; 115 Suppl 5:24–30.
  17. Statistics New Zealand. 2013 Census QuickStats about culture and identity. Pacific peoples ethnic group 2015. [cited: 15/06/2016]; Available from: http://www.stats.govt.nz/Census/2013-census/profile-and-summary-reports/quickstats-culture-identity/pacific-peoples.aspx
  18. Meredith I, Sarfati D, Ikeda T, Blakely T. Cancer in Pacific people in New Zealand. Cancer Causes Control. 2012; 23:1173–1184.
  19. Campbell I, Scott N, Seneviratne S, et al. Breast Cancer Characteristics and Survival Differences between Maori, Pacific and other New Zealand Women Included in the Quality Audit Program of Breast Surgeons of Australia and New Zealand. Asian Pacific Journal of Cancer Prevention. 2015; 16(6):2465–2472.
  20. McKenzie F, Ellison-Loschmann L, Jeffreys M. Investigating reasons for ethnic inequalities in breast cancer survival in New Zealand. Ethn Health. 2011; 16(6):535–549.
  21. McKenzie F, Jeffreys M, ’t Mannetje A, Pearce N. Prognostic factors in women with breast cancer: inequalities by ethnicity and socioeconomic position in New Zealand. Cancer Causes Control. 2008; 19(4):403–411.
  22. Seneviratne S, Campbell I, Scott N, et al. Treatment delay for Maori women with breast cancer in New Zealand. Ethn Health. 2015; 20(2):178–193.
  23. Ministry of Health. Ethnicity Code Tables. 2010 [cited: 13/05/2016]; Available from: http://www.health.govt.nz/nz-health-statistics/data-references/code-tables/common-code-tables/ethnicity-code-tables
  24. Atkinson J, Salmond C, Crampton P. NZDep2013 Index of Deprivation. University of Otago: Dunedin; 2014.
  25. Sobin LH, Gospodarowicz MK, Wittekind C. Union for International Cancer Control (UICC) TNM Classification of Malignant Tumours Seventh Edition. Switzerland: Wiley-Blackwell; 2009.
  26. Sarfati D, Gurney J, Stanley J, et al. Cancer-specific administrative data-based comorbidity indices provided valid alternative to Charlson and NHI indices. J Clin Oncol. 2014; 67(5):586–595.
  27. Ministry of Health. BreastScreen Aotearoa National Policy and Quality Standards. Ministry of Health: Wellington; 2013.
  28. Vona-Davis L, Rose DP. The influence of socioeconomic disparities on breast cancer tumor biology and prognosis: a review. J Womens Health (Larchmt). 2009; 18(6):883–893.
  29. Seneviratne S, Lawrenson R, Scott N, et al. Breast Cancer Biology and Ethnic Disparities in Breast Cancer Mortality in New Zealand: A Cohort Study. PLoS One. 2015; 0(4): e0123523. doi:10.1371/journal.pone.0123523.
  30. BPAC NZ. Increasing the uptake of breast screening. Best Practice Journal. 2011; 34.
  31. Morrell S, Taylor R, Roder D, Robson B. Cohort and Case Control Analyses of Breast Cancer Mortality: BreastScreen Aotearoa 1999–2011. Ministry of Health: New Zealand; 2015.
  32. Ministry of Health. BSA District Health Board Coverage Report: period ending 31 March 2016. Ministry of Health: Wellington; 2016.
  33. Seneviratne S, Lawrenson R, Harvey V, et al. Stage of breast cancer at diagnosis in New Zealand: Impacts of socio-demographic factors, breast cancer screening and biology. BMC Cancer. 2016; 16(1):1–9.
  34. Tin Tin S, Elwood JM, Lawrenson R, et al. Differences in Breast Cancer Survival between Public and Private Care in New Zealand: Which Factors Contribute? PLOS ONE. 2016; 11(4):e0153206.

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