Table 3

Environmental exposures and K-ras codon 12 mutation in pancreatic cancer patients, San Francisco Bay Area 1995–1998

CharacteristicnK-ras negative n = 15K-ras positive n = 46P
Smoking historyN.S.a
Never smoker246 (40%)18 (39%)
Ever smoker379 (60%)28 (61%)
Pack-year (±SD)50.9 (±48.2)31.0 (±20.6)
Years of smoking (±SD)38.3 (±15.4)32.6 (±12.1)
Current smokers13310
Coffee consumption61
Caffeinated1.00b
<1 cup/day7 (47%)17 (37%)
≥1 cups/day8 (53%)29 (63%)
Decaffeinated0.43b
<1 cup/day14 (93%)38 (83%)
≥1 cups/day1 (7%)8 (17%)
Total coffee1.00b
<1 cup/day7 (47%)11 (24%)
≥1 cups/day8 (53%)35 (76%)
Organochlorine levels24717
DDE (ng/g lipid)0.16c
Mean (±SD)2579 (±1648)1547 (±1203)
Median19511287
Range860–5347187–5352
PCBs (ng/g lipid)0.34c
Mean (±SD)633 (±594)408 (±337)
Median304322
Range180–1840  1–1306
  • a N.S. Not significant; analyses done for: ever versus never smoker (P = 1.00, Fisher’s exact test); nonsmoker versus current smoker (P = 1.00, Fisher’s exact test); pack-year (P = 0.26, Student t-test); duration of smoking (P = 0.22, Student’s t-test).

  • b Fisher’s exact test.

  • c Wilcoxon’s rank-sum test.