Ethnic disparity of pancreatic cancer in New Zealand

Abstract

Background: The etiology of pancreatic cancer remains elusive. Identification of high-risk groups may enable targeted study to identify new markers and risk factors.

Aim: To review the epidemiology of pancreatic cancer in New Zealand and identify any differences between ethnic groups.

Methods: All cases notified with pancreatic cancer between 1988 and 1997 were identified from the New Zealand Cancer Registry. Age-specific and age-standardized incidence rates (ASR) of pancreatic cancer were calculated for the total sample and the ethnic subgroups (Maori, Pacific, and Other, which was predominantly European). Data on the site, morphology, stage of tumors, and survival times were also reviewed.

Results: There were 3004 cases over the 10-yr period. Ethnic ASR comparisons demonstrated higher rates in Maori (7.3/100,000) compared with Pacific (6.4/100,000) and the Other (5.6/100,000) ethnic group. Males had higher incidence rates than females in Pacific and Other, but not in Maori because of the unusually high rate among Maori women (7.2/100,000). The most commonly identified site, morphological type, and stage at presentation were the head of the pancreas (80.9% of site-specified cases), adenocarcinoma (44.3% of histologically confirmed cases), and diffuse +/- metastases (69.2% of staged cases), respectively. The median survival time was 92 d, and this did not differ significantly for the Maori and Other ethnic groups.

Conclusion: The Maori have higher rates of pancreatic cancer than other ethnic groups in New Zealand, and do not show the expected male predominance. Maori women currently have one of the highest reported female rates in the world, and are a population that should be further investigated for disease markers and modifiable risk factors.