Cunningham et al. BMC Cancer 2010, 10:674 http://www.biomedcentral.com/1471-2407/10/674 Page 5 of 10 Table 2 Age standardised breast cancer rates, rate ratios and rate differences (compared to European/Other) by ethnicity, age 25+ Ethnicity Total Mäori Total Pacific Total Asian European/Other Cohort 1981-86 1986-91 1991-96 1996-01 2001-04 % Change P (Trend) Pooled 1981-86 1986-91 1991-96 1996-01 2001-04 % Change P (Trend) Pooled 1981-86 1986-91 1991-96 1996-01 2001-04 % Change P (Trend) Pooled 1981-86 1986-91 1991-96 1996-01 2001-04 % Change P (Trend) Pooled SR 95% CI 123 (105 - 140) 142 (126 - 157) 178 (162 - 194) 198 (184 - 212) 210 (194 - 225) 71% < .01 168 (161 - 175) 112 (79 - 145) 146 (115 - 177) 106 (86 - 126) 145 (126 - 165) 141 (121 - 161) 25% 0.38 129 (118 - 141) 69.9 (40.5 - 99.3) 110 (76 - 144) 89.6 (67.5 - 112) 117 (99 - 135) 126 (110 - 142) 80% 0.04 101 (90 - 113) 114 (110 - 118) 140 (136 - 144) 143 (139 - 147) 160 (156 - 164) 170 (166 - 175) 49% < .01 144 (142 - 146) SRR 95% CI 1.07 (0.93 - 1.24) 1.02 (0.91 - 1.14) 1.25 (1.13 - 1.37) 1.23 (1.14 - 1.33) 1.23 (1.14 - 1.33) 0.15 1.17 (1.11 - 1.22) 0.98 (0.73 - 1.32) 1.05 (0.84 - 1.30) 0.74 (0.62 - 0.89) 0.90 (0.79 - 1.04) 0.83 (0.72 - 0.95) 0.39 0.90 (0.82 - 0.98) 0.61 (0.40 - 0.93) 0.79 (0.58 - 1.08) 0.63 (0.49 - 0.80) 0.73 (0.63 - 0.86) 0.74 (0.65 - 0.84) 0.45 0.70 (0.63 - 0.79) 1 1 1 1 1 SRD 95% CI 8.4 (-9.2 - 26) 2.2 (-14 - 18) 35 (18 - 52) 38 (23 - 52) 39 (23 - 56) 0.06 24 (16 - 31) -2.0 (-35 - 31) 6.6 (-25 - 38) -37 (-57 - -17) -15 (-35 - 4.7) -29 (-50 - -9.2) 0.37 -15 (-26 - -3.0) -44 (-74 - -15) -29 (-64 - 5.1) -53 (-76 - -31) -43 (-62 - -25) -44 (-61 - -27) 0.89 -43 (-54 - -31) 0 0 0 0 0 *p test is test for linear trend The incidence pattern for breast cancer amongst Paci- fic women is consistent with our knowledge of breast cancer risk factor distribution in this group. Pacific women are more likely than European women to have children, to commence child bearing earlier and to have more children [37]. Lower alcohol consumption [38] will also contribute to the lower risk of breast cancer amongst Pacific women. The higher rates seen in younger Pacific women (Table 3) may be related to the cancer promoting effect of pregnancy. A similar pattern is seen in the US, with young black women having higher rates than young white women (and older black women having lower rates than older white women), which is thought to relate to earlier childbearing amongst black women [15]. Age at first birth data in New Zealand is only collected for “nuptial” births and is not reported by ethnic group. However based on age specific fertility rates [39] it is apparent that although Pacific women have similar early fertility rates to Māori women, both groups have age specific fertility rates more than double those of European women up to age 25, and so differences in early parity may explain the differences in breast cancer incidence seen between young Pacific and European women. Rates of breast cancer amongst Asian women were consistently lower than those of European and Māori