Table 1

Selected characteristics of breast cancer cases and controls

Total study rangeControlsCasesP
MeanSD (in years)MeanSD (in years)
Year blood collected (mo/yr)3/73–1/908/795.47/795.50.16a
Age at blood collection (yr)18.4–60.041.26.941.16.70.39a
Age at first birthb (yr)16–4023.24.024.14.70.02a
No. of birthsb0–72.21.42.11.50.70a
Serum triglycerides (mg/dl)48–287136.848.8132.548.30.53a
Total cholesterol (mg/dl)88–485206.254.6199.050.20.17a
Total lipids (mg/dl)c355–1311665.5135.4644.9128.90.16a
Date of diagnosis of breast cancer (mo/yr)2/76–12/93n.a.d5/884.5n.a.
Interval between blood sample and diagnosis (yr)2.0–18.2n.a.8.84.8n.a.
No.%No.%P
Occupational category
Professional, technical, sales, clerical4832.25637.60.81e
Manufacturing, labor, craft, repair117.485.4
Farm, fishery2416.12416.1
Service6040.36140.9
Unknown64.0
Region of birthf
Southeast7852.37047.00.17e
Southwest2919.53322.1
Oslo42.7149.4
North2315.52114.1
Other128.0117.4
Region of residence at time of blood collectionf
Southeast8859.08959.70.30e
Southwest2214.83322.1
Oslo149.4128.0
North2214.81510.1
  • a P from paired t test.

  • b In calculating numbers of births and age at first birth, only births before the date of the blood specimen were included.

  • c Total lipids = (2.27 × cholesterol + triglycerides + 62.3).

  • d n.a., not applicable.

  • e P from χ2 test.

  • f Southeast region includes the counties of Ostfold, Akershus, Hedmark, Oppland, Buskerud, Vestfold, Telemark, Aust-Agder, Vest Agder; Southwest region includes the counties of Rogaland, Hordaland, Sogn og Fjordane, More og Romsdal; North region includes the counties of Sor-Trondelag, Nord-Trondelag, Nordland, Troms, and Finnmark.