Gall bladder cancer, extrahepatic bile duct cancer and ampullary carcinoma in New Zealand: Demographics, pathology and survival.

Abstract

The aim of present paper was to document the incidence of gall bladder cancer, cancer of the extrahepatic bile ducts and ampullary carcinoma in New Zealand. Data were collected from the New Zealand Cancer Registry from 1980 to 1997 and combined with national census statistics to give crude and age standardized incidence rates. Over the 18-year study period, 226 carcinomas of the ampulla of Vater, 608 gall bladder cancers, and 486 extrahepatic cholangiocarcinomas were registered. The age standardized incidence rates for gall bladder carcinoma in all New Zealanders were 0.41/100 000 in men and 0.74/100 000 in women. The age standardized incidence rates for gall bladder cancer in Maori were 1.49/100 000 in Maori men and 1.59/100 000 in Maori women. The corresponding age standardized incidence rates for extrahepatic bile duct cancers were 0.67/100 000 in men and 0.45/100 000 in women. There were insufficient cases to calculate an age standardized incidence in Maori or Pacific Islanders. For carcinoma of the ampulla, the age standardized rates were 0.34/100 000 in men and 0.25/100 000 in women. There were insufficient cases to calculate an age standardized incidence rate for Maori or Pacific Islanders. When histology was defined adenocarcinoma was the most common form of cancer occurring in 66% of gall bladder cancers, 91% of extrahepatic bile duct cancers and 70% of ampullary cancers. Most tumours were advanced at presentation with regional or distant metastases present in 72% of gall bladder cancers, 63% of extrahepatic bile duct cancers and 69% of ampullary tumours at diagnosis. Survival was poor with median survivals of 86 days, 151 days and 440 days recorded for gall bladder cancer, extrahepatic bile duct cancer and ampullary cancer, respectively. The demographic profile, pathology and survival of patients with gall bladder cancer, extrahepatic bile duct cancer and ampullary carcinoma are similar in New Zealand to that of other Western countries. However New Zealand Maori have a relatively high incidence of gall bladder cancer, and the incidence is equal in both Maori men and women, while cancers of the extra-hepatic bile duct and ampulla of Vater are rare in Maori. In comparison, cancers of the gall bladder, extrahepatic bile ducts and ampulla are rare in Pacific Islanders.