Table 3. Dietary intake levels of fish and marine n-3 fatty acid in relation to risk of breast cancer by stage of disease and menopausal status, the Singapore Chinese Health Study.

^aRRs were adjusted for age at baseline interview (years), year of recruitment (1993–1998), dialect group (Cantonese, Hokkien), education (no formal education, primary school, secondary school or higher), daily alcohol drinker (yes, no), family history of breast cancer (yes, no), age when period became regular (⩽12, 13–14,15–16, 17+ years or irregular), and number of live births (0, 1–2, 3–4, 5+).

^bThe sum was less than the total number of cases due to exclusion of cases with unknown stage in these analyses.