Table 2.

Relative percent content of various fatty acids in RBC membranes of skin SCC cases and controls

Fatty acidCases, n = 336, mean (SE)*Controls, n = 321, mean (SE)*POR (95% CI)
Saturated fatty acids
    16:0 (palmitic)26.799 (.172)27.243 (.172)0.0630.94 (0.89-1.00)
    18:0 (stearic)17.453 (.147)17.410 (.147)0.8301.02 (0.95-1.09)
Monounsaturated fatty acids
    16:1n-7 (palmitoleic)0.646 (0.022)0.725 (0.023)0.0110.49 (0.30-0.81)
    18:1n-7c (vacceinic)0.715 (0.021)0.750 (0.021)0.2170.67 (0.41-1.10)
    18:1n-9c (oleic-cis)17.798 (0.105)18.001 (0.106)0.1600.96 (0.87-1.06)
    18:1n-9t (oleic-trans)1.326 (0.039)1.375 (0.039)0.3610.86 (0.67-1.12)
Polyunsaturated fatty acids
    18:2n-6c (linoleic-cis)13.073 (0.106)13.034 (0.106)0.7911.01 (0.92-1.12)
    18:2n-6t (linoleic-trans)0.293 (0.017)0.336 (0.017)0.0630.44 (0.24-0.82)
    18:3n-3 (linolenic)0.289 (0.020)0.304 (0.020)0.5910.79 (0.46-1.36)
    20:2n-9 (eicosadenoic)0.479 (0.027)0.476 (0.028)0.9411.02 (0.70-1.49)
    20:3n-9 (eicosatrienoic)1.786 (0.044)1.742 (0.044)0.4651.04 (0.83-1.31)
    20:4n-6 (arachidonic)15.301 (0.171)14.644 (0.171)0.0051.08 (1.02-1.15)
Long-chain N-3 polyunsaturated fatty acids
    20:5n-3 (eicosapentaenoic)0.601 (0.030)0.606 (0.030)0.9040.97 (0.68-1.37)
    22:6n-3 (docosahexaenoic)3.441 (0.060)3.355 (0.060)0.3011.12 (0.95-1.33)
N3/N6 ratio0.1511 (0.002)0.1518 (0.002)0.8404.57 (1.27-16.49)
P/S ratio0.8076 (0.008)0.7846 (0.008)0.0463.00 (0.88-10.18)
  • * Relative % mean and SE, standardized as weight percentages of the total 14 fatty acids extracted; adjusted for age, sex, lab.

  • P for t test of difference between adjusted means for cases and controls.

  • OR and 95% CI adjusted for age, sex, lab, freckles on arm, ability to tan, and history of actinic keratosis.