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Differential Colon Cancer Survival by Ethnicity in New Zealand

About the project

Objective

The main objectives of the Differential Colon Cancer Survival by Ethnicity in New Zealand projects main objectives were to:

  1. Assess the extent to which survival from colon cancer varies between Māori and non-Māori independently of stage at diagnosis
  2. To identify post-diagnosis factors contributing to this inequality, including differences in treatment and follow-up

Recent research suggests that Māori have worse survival rates from cancer (including colon cancer) compared with non-Māori. Moreover, this difference appears at least partly due to factors occurring after diagnosis.

Overview

New Zealanders with colon cancer were identified from the cancer registry (n=642). Information was obtained about their cancer and treatment from health care records, pathology records, and the national mortality database. We have compared characteristics important to survival between Māori and non-Māori. We have also conducted survival analyses assessing the impact of disease, patient, treatment, and healthcare factors on survival disparities.

Results

The results of this study are currently in the process of being published and disseminated more generally. The main findings were that:

  • Māori patients have significantly poorer survival from colon cancer compared with non-maori patients (HR 1.33)
  • Greater comorbidity levels and differences in health care access are both important mediators of worse survival in Māori (each accounts for ~ 1/3 of the total disparity)

Funder

cancer-society-logoThis research was funded by The Cancer Society of New Zealand.

Publications

Hill S, Sarfati D, Blakely T, Robson B, Purdie G, Chen J, Dennett E, Cormack D, Cunningham R, Dew K, McCreanor T, Kawachi I. Ethnicity and Management of Colon Cancer in New Zealand: Do Indigenous Patients Get a Worse Deal? Cancer 2010; 116: 3205-14

Hill S, Sarfati D, Blakely T, Robson B, Purdie G, Chen J, Dennett E, Cormack D, Cunningham R, Dew K, McCreanor T, Kawachi I. Survival disparities in Indigenous and non-Indigenous New Zealanders with colon cancer: the role of patient comorbidity, treatment and health service factors. J Epidemiol Community Health 2010; 64: 117-123

Sarfati D, Hill S, Purdie G, Dennett E, Blakely T. How well does routine hospitalisation data capture information on comorbidity in New Zealand? New Zealand Medical Journal 2010; 123(1310) :50-61

Hill S, Sarfati D, Blakely T, Robson B, Purdie G, Chen J, Dennett L, Cormack D, Cunningham R, Dew K, McCreanor T, Kawachi I. Survival disparities in Indigenous and non-Indigenous New Zealanders with colon cancer: the role of patient comorbidity, treatment and health service factors. J Epidemiol Community Health. 2010; 64: 117-123

Hill S, Sarfati D, Blakely T, Robson B. Ethnicity and cancer treatment in New Zealand: do Maori patients get a worse deal? J Epidemiol Community Health 2009; 63(13)

Sarfati D, Hill S, Blakely T, Robson B, Purdie G,  Dennett L, Cormack D, Dew K. The effect of comorbidity on the use of adjuvant chemotherapy and survival from colon cancer: a retrospective cohort study. BMC Cancer 2009; 9(116)

Cunningham R, Sarfati D, Hill S, Dennett E, O’Donnell A. Colon cancer management in New Zealand 1996-2003. New Zealand Medical Journal 2009; 122(1294): 51-60

Cunningham R, Sarfati D, Hill S, Kenwright D. An Audit of Colon Cancer Data on the New Zealand Cancer Registry. New Zealand Medical Journal 2008; 121(1279): 46-56

Sarfati D, Blakely T, Hill S. The epidemiology of relative survival analysis. Australasian Epidemiologist 2008; 15(1): 21-3 [abstract only]

Presentations

Hill SE, Sarfati D. Survival differences between indigenous and non-indigenous New Zealanders with colon cancer: contribution of disease, patient and health care factors (3818).  International Epidemiology Association, XVIII World Congress of Epidemiology, Porto Alegre, Brazil, 21 September 2008. 

Hill SE, Sarfati D, Blakely T, Robson B, Purdie G, Kawachi I. Survival differences between indigenous and non-indigenous New Zealanders with colon cancer: contribution of disease, patient and health care factors.  Society of Epidemiology Research, Xth Annual Scientific meeting, Chicago, IL, 26 June 2008.  In: American Journal of Epidemiology 2008;167(S11):S128

Sarfati D, Hill S, Blakely T, Robson B, Purdie G,  Dennett L, Cormack D, Dew K.  Comorbidity and colon cancer.  The effect of comorbidity on the use of adjuvant chemotherapy and survival from colon cancer.  (Poster)  International Epidemiology Association, XVIII World Congress of Epidemiology, Porto Alegre, Brazil, 21 September 2008.

Sarfati D, Blakely T, Hill S.  The epidemiology of relative survival analyses. Australasian Epidemiologist 2007; 14(3): 109

Sarfati D. Ethnic inequalities in cancer survival. Public Health Association Conference. 2007, Auckland

Hill SE; Sarfati D. 2006.  How should we measure disparities in cancer survival? – Māori  and non-Māori  New Zealanders with colon cancer: cause-specific vs relative survival.  Australasian Epidemiologist 2006; 13 (3): 50.

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