Cancer incidence in four pacific countries: Tonga, Fiji Islands, Cook Islands and Niue.

BACKGROUND: We have established and/or upgraded cancer registries in four Pacific countries, a region where few cancer registries exist. We report age-standardised cancer incidence in Tonga (2000-2005), Fiji (2002-2005), Cook Islands (2000-2005) and Niue (2000-2005), and in Pacific people in New Zealand (2000-2005).
METHODS: In each country we identified incident cancer cases by reviewing hospital discharge, death registration, cancer registration records, and pathology reports. The primary site and morphology data were coded using ICD-0, and age-standardised incidence rates were calculated.
RESULTS: Age-standardised cancer incidence rates for Pacific people in New Zealand (315 per 100,000 person-years in females, 379 in males) were similar to those for New Zealand overall (322 in females, 404 in males); incidence rates were lower in the Pacific, with rates of 195 and 151 per 100,000 person-years for females and males respectively in Tonga, 231 and 126 in Fiji, 165 and 142 in the Cook Islands, and 228 and 131 in Niue. However, some specific cancers were elevated in the Pacific including cervical cancer (16 per 100,000 in Tonga, 51 in Fiji, 17 in Cook Islands, and 26 in Niue compared with 10 in Pacific people in New Zealand, and 8 in New Zealand overall), liver cancer (rates of 8, 5, 19, 0, 7, and 2 respectively) and uterine cancer (rates of 24, 18, 47, 19 and 12 respectively).
CONCLUSIONS: Cancer incidence in the Pacific is lower than for Pacific people living in New Zealand. Environmental rather than genetic factors are most likely to explain these patterns, and cancer incidence in the Pacific is likely to increase to rates similar to those in New Zealand as the region becomes more 'westernised' The high rates of cervical cancer and liver cancer in the Pacific indicate an important role of